LUCERO, Circuit Judge.
This case arises from a reduction in force (“RIF”) instituted in 1993 by defendant Sea-gate Technology, Inc., a manufacturer of computer equipment. As a result of the RIF, more than 200 employees at Seagate’s Oklahoma City facility were laid off. Many of the laid-off employees had worked at the Oklahoma City facility for more than a decade. Some of the plaintiffs in this case had more than twenty years seniority when they were let go. Twenty-seven former employees sued Seagate for violation of various federal and state antidiscrimination laws. Some of the plaintiffs voluntarily dismissed their claims, and the district court granted Seagate summary judgment as to most of the others. The judgment became final when the remaining plaintiffs settled and the district court entered a final judgment. Eight plaintiffs remain parties to this appeal.
Plaintiffs raise two distinct objections to summary judgment. First, they argue that it was reversible error to allow Seagate to submit a reply brief with additional materials after plaintiffs had responded to Seagate’s original summary judgment motion, but not to permit plaintiffs to file a surreply controverting the arguments and materials contained in the reply. Second, they contend that questions of material fact remain with respect to each plaintiff and that summary judgment was thus improper.
I
In 1993, Seagate decided to reorganize its Oklahoma City facility and reduce the number of employees working there. According to the RIF procedures described in Seagate’s employee handbook, “[i]n determining which employees will be subject to a reduction in force, the Company will take into account, among other things, operational requirements, performance and potential. Where these factors are equal, length of service will be taken into account.” See Appellants’ App. at 228.
In an affidavit submitted to the district court, Seagate’s Director of Human Services, Lowell Yandell, elaborated on this scheme. According to Yandell, operational requirements dictated the total number of employees to be cut within each job code. Thereafter, employee performance determined which employees would number in the final lay-off total. Where one employee’s performance ranking was equal to another’s, length of service was used as a tiebreaker. If two employees had identical seniority, the employee born on the earliest day of the month was selected first.
For purposes of the RIF, Seagate measured performance in two ways. Employees who had recently been subject to formal disciplinary proceedings were chosen for layoff before any other employee within their [1163]*1163job code.1 If there were no such documented disciplinary actions, Seagate stated that it considered the employee’s most recent written performance evaluation rating, which was measured on a scale of one to five. For all plaintiffs, the most recent written performance evaluations were compiled in a “CHA-PA” report, dated July 26, 1993, that also lists the date of their final evaluation. In some cases, employees were evaluated on a zero-to-500 point scale that was converted into a performance evaluation corresponding to the CHAPA one-to-five scale.
Plaintiffs alleged principally that the RIF, as applied to them, was a pretext for illegal discrimination. Seagate moved for summary judgment, asserting that all lay-off decisions were made in strict accordance with the RIF guidelines outlined above. In response, plaintiffs disputed that contention by introducing a Seagate evaluation document as their Exhibit 53. Plaintiffs argued that this document showed they should have been retained in place of employees who were not laid off; that the RIF criteria, including potential and disciplinary history, were used selectively; and that strict seniority was not applied.
The district court then allowed Seagate to file a reply brief, in which it explained the preliminary nature of Exhibit 53 and reiterated that the RIF criteria had been consistently applied. Plaintiffs moved to strike Seagate’s reply brief or, in the alternative, to file a surreply. The district court denied both motions. Thereafter, the district court granted Seagate summary judgment with respect to all of the appellants. As to appellants Clark, Bush, Bobo and Henson, the district court concluded that a prima facie case of discrimination had not been made. With respect to all eight appellants, it concluded that Seagate’s RIF was a legitimate nondiseriminatory reason for termination and that appellants had failed to carry their burden of presenting facts that would allow a factfinder to conclude that the RIF was applied in a pretextual manner. Eight plaintiffs timely appealed.
II
Appellants first argue that the district court committed reversible error in allowing Seagate to file a reply after plaintiffs responded to Seagate’s motion for summary judgment, while denying plaintiffs the opportunity to file a surreply. The substance of Seagate’s reply is in three parts: (1) the existence of performance point totals inconsistent with the performance ratings used in the RIF had no effect on plaintiffs’ selection for the RIF; (2) plaintiffs’ previous attack on the use of potential as a criterion for RIF consideration now precludes assertions that the RIF did not properly consider potential; and (3) the voluntary dismissal of discrimination claims by many of the plaintiffs suggests the remaining plaintiffs likewise have no valid claims.
The parties disagree as to what standard of review we should apply to the district court’s decision to allow a reply brief. Appellants argue that we should review the district courts’s decision de novo. They contend that the district court’s error is jurisdictional and, thus, requires reversal regardless of any showing of prejudice. Additionally, appellants argue that some of their number were in fact prejudiced by the district court’s reliance on new material to which they had no opportunity to respond. Seagate contends that we should review the district court’s decision only for an abuse of discretion. Seagate argues that the district court acted within its discretion in allowing the company to file a reply brief without allowing plaintiffs a surreply and, further, that no unfair prejudice occurred as a result of the district court’s consideration of Seagate’s reply-
Federal Rule of Civil Procedure 56 implicitly requires the district court to allow the nonmoving party an opportunity to respond before summary judgment is entered against it. See Fed.R.Civ.P. 56(c) (“The motion shall be served at least 10 days before the time fixed for the hearing. The adverse [1164]*1164party prior to the day of hearing may serve opposing affidavits.”); Celotex Corp. v. Catrett, 477 U.S. 317, 326, 106 S.Ct. 2548, 91 L.Ed.2d 265 (1986) (“[District courts are widely acknowledged to possess the power to enter summary judgments sua sponte, so long as the losing party was on notice that she had to come forward with all of her evidence.”). In our circuit, “[i]t is settled law that noncompliance with the time provisions of Rule 56(c) deprives the court of authority to grant the motion for summary judgment unless the opposing party has waived this requirement.” Osbakken v. Venable, 931 F.2d 36, 37 (10th Cir.1991). Here, appellants analogize Seagate’s reply to an initial summary judgment motion, and suggest that the district court had ho authority to grant summary judgment without • allowing plaintiffs the opportunity to respond to the new materials.
Rule 56 neither authorizes nor forbids a reply brief by the party moving for summary judgment. In the absence of a specific federal rule, the Federal Rules of Civil Procedure permit federal judges to regulate practice “in any manner consistent with federal law, rules adopted under 28 U.S.C. §§ 2072 and 2075, and local rules of the district.” See Fed. R.Civ.P. 83(b). Under the local rules of the Western District of Oklahoma, authorized under Fed.R.Civ.P. 83(a), “[rjeply ... briefs are not encouraged and may be filed only upon application and leave of Court.” LR7.1(g) (1997). In this case, the district court’s actions are properly viewed as stemming from the authority granted by Rule 83.
Although there is no clear statutory prescription as to the standard of appellate review, the permissive language of Local Rule 7.1(g) and of both provisions of Federal Rule 83 implies that we must give the district court appropriate deference on appeal. See Pierce v. Underwood, 487 U.S. 552, 558-59, 108 S.Ct. 2541, 101 L.Ed.2d 490 (1988). Moreover, “[i]t is especially common for issues involving what can broadly be labeled ‘supervision of litigation’ ... to be given abuse-of-discretion review.” Id. at 558 n. 1. The question presented here, that of determining whether the district court may consider evidence and issues raised by the party moving for summary judgment in a reply brief without allowing the opposing party to respond, fits best within this “supervision of litigation” framework. Consequently, we review the trial court’s managing its docket and supervising the parties in this respect for an abuse of discretion only. Cf. Walter v. Morton, 33 F.3d 1240, 1244 (10th Cir.1994) (holding trial court did not abuse its discretion by denying summary judgment without giving movant opportunity to file reply brief).
Under the abuse of discretion standard, “a trial court’s decision will not be disturbed unless [we have] a definite and firm conviction that the lower court has made a clear error of judgment or exceeded the bounds of permissible choice in the circumstances.” McEwen v. City of Norman, 926 F.2d 1539, 1553-54 (10th Cir.1991) (quoting United States v. Ortiz, 804 F.2d 1161, 1164 n. 2 (10th Cir.1986)). Appellants contend that the district court had no “permissible choice” but to allow a surreply once it had accepted the materials in Seagate’s reply. That contention is incorrect. Having accepted the reply brief, the district court in fact had two permissible courses of action. It could either have permitted a surreply or, in granting summary judgment for the movant, it could have refrained from relying on any new material contained in the reply brief.
Rule 56(c) requires the nonmoving party to be given notice and a reasonable opportunity to respond to the movant’s summary judgment materials. See Celotex, 477 U.S. at 326, 106 S.Ct. 2548 (holding that summary judgment is to be entered only if nonmovant on notice that it must come forward with all its evidence); Osbakken, 931 F.2d at 37 (holding that purpose of ten-day period in Rule 56(c) is to provide nonmovant with opportunity to prepare defense to summary judgment). Thus, when a moving party advances in a reply new reasons and evidence in support of its motion for summary judgment, the nonmoving party should be granted an opportunity to respond. See Cia. Petrolera Caribe, Inc. v. Arco Caribbean, Inc., 754 F.2d 404, 410 (1st Cir.1985). However, if the district court grants summary judgment for the movant without relying on the new materials and arguments in the mov-[1165]*1165ant’s reply brief, it does not abuse its discretion by precluding a surreply.
The issue is not jurisdictional. It is true that under Rule 56(e) a court lacks authority to enter summary judgment until ten days have run from the filing of the motion. But once that requirement has been met and the motion is at issue, the court does not lose jurisdiction simply because it accepts a reply brief from the movant. Rule 56(c) simply requires that if the court relies on new materials or arguments in a reply brief, it may not forbid the nonmovant from responding to these new materials. See id.
In this case, we are not convinced that the district court relied on any new materials or arguments contained in Seagate’s reply brief. We need not resolve the issue definitively, however, because we conclude that the district court should not have granted summary judgment as to any of the appellants even on the basis of all the evidence and arguments before the court. Had the district court abused its discretion in refusing the appellants an opportunity to respond to any reply brief materials or argument, it would not affect our decision today.
Ill
Summary judgment should be granted when “there is no genuine issue as to any material fact and ... the moving party is entitled to a judgment as a matter of law.” Ped.R.Civ.P. 56(c). In reviewing the district court’s decision to grant summary judgment, we view the evidence in the light most favorable to the nonmoving party. Kaul v. Stephan, 83 F.3d 1208, 1212 (10th Cir.1996). The substantive law at issue determines which facts are material in a given case. Anderson v. Liberty Lobby, Inc., 477 U.S. 242, 248, 106 S.Ct. 2505, 91 L.Ed.2d 202 (1986). “Only disputes over facts that might affect the outcome of the suit under the governing law will properly preclude the entry of summary judgment.” Id.
All eight appellants raise claims of age discrimination under the Age Discrimination in Employment Act of 1967 (“ADEA”), 29 U.S.C. §§ 621-634. We assess these claims under the burden-shifting framework of McDonnell Douglas Corp. v. Green, 411 U.S. 792, 93 S.Ct. 1817, 36 L.Ed.2d 668 (1973). To make out a prima facie case of discriminatory discharge under the ADEA, a claimant affected by a RIF must prove: (1) that she is within the protected age group; (2) that she was doing satisfactory work; (3) that she was discharged despite the adequacy of her work; and (4) that there is some evidence the employer intended to discriminate against her in reaching its RIF decision. See Ingels v. Thiokol Corp., 42 F.3d 616, 621 (10th Cir.1994). The fourth element may be established “through circumstantial evidence that the plaintiff was treated less favorably than younger employees during the [RIF].” Id.
Establishing a prima facie case of age discrimination under the ADEA creates a presumption of discriminatory intent that the defendant may rebut by asserting a facially nondiscriminatory reason for the employee’s termination. Id. The plaintiff may then resist summary judgment if she can present evidence that that proffered reason was pretextual, “i.e. unworthy of belief,” see Randle v. City of Aurora, 69 F.3d 441, 451 (10th Cir.1995), or otherwise introduces evidence of illegal discriminatory motive, see id. at 453.2
[1166]*1166Five of the plaintiffs — Beaird, Bobo, Bush, Clark and Johnson — also argue that their inclusion within the RIF was the product of intentional racial discrimination in violation of Title VII of the Civil Rights Act, 42 U.S.C. § 2000e-2(a)(l), and 42 U.S.C. § 1981. In addition, Beaird asserts that her discharge constituted gender discrimination in violation of Title VII. AU these claims are assessed under the same McDonnell Douglas order of proof. See Branson, 853 F.2d at 770 (ADEA and Title VII claims both subject to McDonnell Douglas indirect method of proof); Ran-dle, 69 F.3d at 450 (assessing § 1981 claims under McDonnell Douglas framework).
A
The district court ruled that four of the plaintiffs — Bobo, Bush, Clark and Henson — failed to establish prima facie cases of age discrimination. The district court also ruled that three plaintiffs — Bobo, Bush and Clark — failed to establish prima facie cases of racial discrimination. There is no apparent dispute on appeal that these plaintiffs each established the first three elements of a prima facie case of race and age discrimination.3 The district court appears to have based its decision on the fourth element— that is, that none of these employees had shown Seagate treated them less favorably than their younger or nonminority counterparts. See Appellants’ App. at 1082-84, 1093. We disagree. Although this circuit has not fully defined the fourth element of a prima facie case of discrimination in the context of a RIF, that element was more than satisfied as to each of these plaintiffs.
Our most complete statement of the fourth element to date is Branson, which holds: “Evidence that an. employer fired qualified older employees but retained younger ones in similar positions is sufficient to create a rebuttable presumption of discriminatory intent....” Branson, 853 F.2d at 771. We have not further described such evidence, thus leaving unanswered such questions as whether a single younger employee retained in a similar position is sufficient to establish the fourth element, or how similar a position must be in order to be relevant under Branson. To do so, we return to Branson’s fundamental fourth-prong requirement that the plaintiff introduce “evidence, circumstantial or direct, from which a factfinder might reasonably conclude that the employer intended to discriminate in reaching the decision at issue.” Id. (quoting Williams v. General Motors Corp., 656 F.2d 120, 129 (5th Cir.1981)). To interpret this standard, we look in turn to the basic function of the plaintiffs prima facie case within the McDonnell Douglas order of proof, mindful that the burden-shifting framework “allows victims of age discrimination to prevail without presenting any evidence that age was a determining factor in the employer’s motivation.” La Montagne v. American Convenience Prods., Inc., 750 F.2d 1405, 1409-10 (7th Cir.1984).
A prima facie case of discrimination is one sufficient to raise a presumption of intentional discrimination. St. Mary’s Honor Ctr. v. Hicks, 509 U.S. 502, 506, 113 S.Ct. 2742, 125 L.Ed.2d 407 (1993). Left unanswered by the defendant, that presumption mandates a finding of intentional discrimination, see id., because a prima facie case “eliminates the most common nondiscriminatory reasons for the plaintiffs rejection,” Texas Dep’t of Community Affairs v. Burdine, 450 U.S. 248, 254, 101 S.Ct. 1089, 67 L.Ed.2d 207 (1981), namely a “lack of qualifications or the absence of a vacancy in the job sought,” International [1167]*1167Brotherhood of Teamsters v. United States, 431 U.S. 324, 358 n. 44, 97 S.Ct. 1843, 52 L.Ed.2d 396 (1977). More specifically, the second element of the McDonnell Douglas prima facie case — that the plaintiff be “qualified,” McDonnell Douglas, 411 U.S. at 802, 93 S.Ct. 1817 — and the fourth element — that the “position remained open,” id. — perform this elimination role. “Elimination of these reasons for the refusal to hire is sufficient, absent other explanation, to create an inference that the decision was a discriminatory one.” Teamsters, 431 U.S. at 358 n. 44, 97 S.Ct. 1843.
The prima facie case raises an inference of discrimination precisely because once the two most common nondiseriminatory reasons for an adverse employment decision are eliminated, that decision, “if otherwise unexplained, [is] more likely than not based on the consideration of impermissible factors.” Burdine, 450 U.S. at 254, 101 S.Ct. 1089 (quoting Furnco Constr. Corp. v. Waters, 438 U.S. 567, 577, 98 S.Ct. 2943, 57 L.Ed.2d 957 (1978)). Thus, the fourth element of Bran-son should be understood to parallel the fourth element of McDonnell Douglas by eliminating “lack of vacancy” as a legitimate nondiseriminatory motive for the employment decision. Once the first three elements have been satisfied, that elimination is all that is required to give rise to a prima facie case. See Branson, 853 F.2d at 771 n. 5 (indicating no higher quantum of proof required to establish a prima facie case in RIF situation). The language used in Branson should not be understood to require a plaintiff to produce evidence that age was a determining factor in the employer’s motivation. Such an understanding would effectively fuse the prima facie and pretext steps of McDonnell Douglas and “obviate[ ] the central purpose behind the McDonnell Douglas method, which is to relieve the plaintiff of the burden of having to uncover what is very difficult to uncover — evidence of discriminatory intent.” Oxman v. WLS-TV, 846 F.2d 448, 454-55 (7th Cir.1988).
Of course, in a RIF case, the plaintiff cannot actually point to a continuing vacancy because her position has been eliminated. She can, however, point to circumstances that show that the employer could have retained her, but chose instead to retain a younger employee.4 In such circumstances, “lack of vacancy” cannot explain the contested employment decision because the employer prefers to retain a younger employee in a position for which the plaintiff is qualified. Even though certain exigencies of RIF cases may explain the employer’s action in such circumstances, “these exigencies are best analyzed at the stage where the employer puts on evidence of a nondiseriminatory reason for the discharge.” Branson, 853 F.2d at 771.
For instance, a plaintiff who is fired pursuant to a RIF and who held a similar position to a younger retained employee can satisfy the fourth element. See Krause v. Dresser Indus., Inc., 910 F.2d 674, 677 (10th Cir.1990) (holding that prima facie case established where employer fires fifty-two year old accountant pursuant to RIF, but retains one younger employee in similar position); Herold v. Hajoca Corp., 864 F.2d 317, 320 (4th Cir.1988); Branson, 853 F.2d at 771 (“Evidence that an employer fired qualified older employees but retained younger ones in similar positions is sufficient to create a rebuttable presumption of discriminatory intent and to require the employer to articulate reasons for its decision.”). The company’s decision to reduce its workforce does not in itself legitimate the employer’s choice to fire the employee from the protected class rather [1168]*1168than the younger employee. “Lack of vacancy” is thereby eliminated as a nondiscriminatory explanation for that plaintiffs dismissal and, assuming the first three elements are met, a prima facie case has been shown.5
Here, the evidence in the record establishes that for each of the four plaintiffs noted above, at least one younger and/or nonminority employee was retained in the same job code. For example, in job code 1433, to which Bobo, Bush and Clark all belonged, Terry Smith, a white thirty-seven year-old employee was retained. See Appellants’ App. at 172-73. In job code 276X, to which Henson belonged, numerous younger employees were retained. See id. at 208-09. Under Rule 56(c), a movant for summary judgment has the burden of “pointing out to the district court ... [the] absence of evidence to support the nonmoving party’s case.” See Celotex, 477 U.S. at 325, 106 S.Ct. 2548. With regard to the prima facie case, the movant in this case was unable to carry its burden.
B
Seagate advances the RIF and its implementing criteria as a facially nondiscriminatory reason for its decision to lay off the plaintiffs. The company has therefore met its burden under the second step of McDonnell Douglas. See Furr v. Seagate Technology, Inc., 82 F.3d 980, 985 (10th Cir.1996), cert. denied, — U.S.-, 117 S.Ct. 684, 136 L.Ed.2d 608 (1997). In a RIF case, a plaintiff can demonstrate pretext in three principal ways.6
First, she can argue that her own termination does not accord with the RIF criteria supposedly employed. In this case, certain appellants contend that had employee potential been considered according to the employer’s own RIF formula, they would have been retained. This kind of evidence can in some cases suffice to substantiate pretext. See Christie v. Foremost Ins. Co., 785 F.2d 584, 586-87 (7th Cir.1986) (holding that failure of defendant to comply with its own RIF policy allowed jury to conclude RIF was pretextual). But minor inconsistencies in the application of RIF criteria may be too insubstantial to allow a reasonable jury to infer that the RIF was pretextual. See Lucas v. Dover Corp., 857 F.2d 1397, 1402 (10th Cir.1988).
Second, a plaintiff can adduce evidence that her evaluation under the defendant’s RIF criteria was deliberately falsified or manipulated so as to effect her termination or otherwise adversely alter her employment status. See, e.g., Gustovich v. AT & T Communications, Inc., 972 F.2d 845, 848 (7th Cir.1992) (“To make progress, the plaintiffs had to come up with evidence implying that the performance evaluations had been ‘cooked’ in order to do in the older workers.”). All the appellants in this case make claims of this kind. One method of demonstrating manipulation or falsification of evaluation is to produce evidence that a supervisor responsible for assessing her performance displayed ageist animus.
Third, a plaintiff can adduce evidence that the RIF is more generally pretex-tual. For instance, a plaintiff may establish that an employer actively sought to replace a number of RIF-terminated employees with new hires. Bush, Bobo and Henson all bring claims of this nature. Statistical evidence may, in certain circumstances, be relevant to this purpose. See Fallis v. Kerr-McGee Corp., 944 F.2d 743, 746 (10th Cir.1991). Contrary to defendant’s argument, however, statistical evidence cannot defeat the pretext claim of an individual plaintiff where the plaintiffs case rests on non-statistical evidence. “A racially balanced work force cannot immunize an employer from liability for specific acts of discrimination.” Furnco, 438 U.S. at 579, 98 S.Ct. 2943.
[1169]*11691. Ruth Noran
Noran is the only appellant fired from job code 1432. Seagate claims that she was fired pursuant to operational requirements that dictated the lay-off of ten employees from that job code. As the only employee from this job code with a score of two on the CHAPA report, she was selected first for termination.
There are two pieces of evidence in the record that together support a finding of pretext in this ease: (1) plaintiffs’ Exhibit 53; and (2) a final performance evaluation dated April 19, 1993. Exhibit 53, submitted by plaintiffs in response to Seagate’s motion for summary judgment, is an undated document headed “Employees Identified for RIF Using Statewide Pooling.” For Noran’s job code, it lists eleven employees ranked in ascending order according to their performance points evaluation. Noran is listed third, with a total of 240 points. See Appellants’ App. at 795.
Of the eleven listed, only four were in fact laid off. According to Seagate, the evaluations listed in Exhibit 53 were irrelevant because the final performance criterion selected for purposes of the RIF was performance grade rather than performance points. Additionally, Seagate claims that Noran’s ease was appropriately dismissed because, by the time final RIF decisions were made, No-ran’s performance rating listed in Exhibit 53 had been replaced by a later and lower review, which scored Noran at 180 points for a CHAPA performance grade of two.
Noran cannot defeat summary judgment by claiming that she would have been retained if different RIF criteria had been used. Seagate may choose to conduct its RIF according to its preferred criteria of performance — that is, performance grade as opposed to performance points — and we will not disturb that exercise of defendant’s business judgment. See Doan v. Seagate Technology, Inc., 82 F.3d 974, 978 (10th Cir.1996), cert. denied, — U.S.-, 117 S.Ct. 684, 136 L.Ed.2d 608 (1997). That is so even if it appears to Noran that the points scale would have represented a better tool of performance evaluation. The ADEA does not require Seagate’s business decisions to be wise — just nondiscriminatory. See Lucas, 857 F.2d at 1403.
But this principle does not immunize all potential “business judgments” from judicial review for illegal discrimination. See Sanchez v. Philip Morris Inc., 992 F.2d 244, 247 (10th Cir.1993) (when employer invokes business judgment rule in discrimination context, “[t]he reality of the entire situation must be examined”). Such a doctrine would defeat the entire purpose of the ADEA. See Montana, 869 F.2d at 106; Graefenhain v. Pabst Brewing Co., 827 F.2d 13, 21 & n. 8 (7th Cir.1987), overruled on other grounds by Coston v. Plitt Theatres, Inc., 860 F.2d 834 (7th Cir.1988). There may be circumstances in which a claimed business judgment is so idiosyncratic or questionable that a factfinder could reasonably find that it is a pretext for illegal discrimination. See Sanchez, 992 F.2d at 247; Thornbrough v. Columbus & Greenville R.R., 760 F.2d 633, 647 (5th Cir.1985), overruled on other grounds by Hicks, 509 U.S. 502, 113 S.Ct. 2742, 125 L.Ed.2d 407; Loeb v. Textron, Inc., 600 F.2d 1003, 1012 n. 6 (1st Cir.1979). Without more, however, the choice of performance grade over points cannot reasonably be thought to evidence pretext. There is simply no inference of foul play about that choice.
But Noran does more than question that choice. She argues further that Exhibit 53 shows that Seagate improperly manipulated her final CHAPA performance evaluation, which gave her 180 points for a two rating, in order to ensure her termination. Under the RIF criteria, had Noran’s 240 point score stood unaltered, she would have had a CHA-PA score of three and been retained. Of course, Noran cannot establish pretext by demonstrating the mere opportunity for manipulation. To allow her to do so would effectively — and incorrectly — require a defendant to prove nondiscrimination. Here, however, Noran has produced further evidence that raises the necessary inference of manipulation.
The record contains a final performance evaluation of Noran dated April 19, 1993. See Appellants’ App. at 265. But she did not receive its results until July 26, 1993, see id. [1170]*1170at 172, 895, three days after Seagate had conclusively decided to terminate her, see id. at 775. Even that might only point to the opportunity for employer misconduct but for the fact that the relevant portion of Exhibit 53, which lists her as having 240 points, was evidently compiled on or after June 28, 1993. See id. at 172, 795 (showing that Exhibit 53 contains point scores for Owens, Lashley and McCartney, all of which are dated June 28, 1993, on the CHAPA table). In other words, more than two months after Seagate claims to have completed the 180-point/grade-two performance evaluation that ostensibly led to Noran’s termination, the company was describing her on internal documents as having 240 points. That latter score would have resulted in a grade-three CHAPA ranking and Noran’s retention. One legitimate inference is that Seagate resolved to alter the score for Noran’s April evaluation after June 28, 1993. That legitimate inference of purposeful manipulation is sufficient to permit a jury to find pretext.7 Thus, there are genuine issues of material fact that preclude the entry of summary judgment against Noran.
2. Rosa Clark
Clark is one of four appellants fired from job code 1433. Seagate claims that operational requirements called for fifteen lay-offs in this job code. Clark received a performance grade of three on the CHAPA report. Because no employee in her job code scored lower, Seagate identified those to be laid off in reverse order of seniority. With 22.77 years of credited seniority, Clark was terminated as the tenth most junior employee with a three rating.
Clark attempts to rely on Exhibit 53, which indicates that she would have been retained had Seagate chosen to rely on points alone to identify lay-offs.8 As noted above, we agree with Seagate that its choice of performance criteria cannot properly evidence pretext.
Nor is Clark’s opinion that discrimination was pervasive at Seagate sufficient to establish pretext. Without specific examples of such discrimination, Clark’s views are “mere conjecture” and, thus, an insufficient basis on which to deny summary judgment. See Branson, 853 F.2d at 772. From the record before us, the instances of claimed discrimination that she does describe, such as her mistreatment by a supervisor, can only be speculatively attributed to discriminatory animus, and “speculation ... will not suffice for evidence.” Doan, 82 F.3d at 977.
Clark’s final argument for pretext is based on a comparison between herself and Mary McCartney, a white employee retained in job code 1432. Had the two employees been in the same job code, McCartney would have been laid-off before Clark because she scored a three in her final performance evaluation and was the less senior of the two. Seagate argues that comparisons across job codes are not probative of pretext because employees in different codes are not similarly-situated. The company insists that it is the plaintiffs’ obligation to show that Seagate’s pooling of employees into job codes for purposes of the RIF was not justified.
Seagate is not entirely correct. When an employer’s RIF criteria include job categorization, an employer must explain the basis for that categorization or risk a finding of pretext. Cf. Bell v. AT & T, 946 F.2d 1507, 1511 (10th Cir.1991) (recognizing that where employer decides to limit RIF to certain groups, it is incumbent on employer to explain reason for that limitation). “Otherwise, a sophisticated employer could immunize itself from liability by placing a minority [1171]*1171employee in a group with employees with greater seniority while banding all other employees with less seniority in another group not at risk of termination. In that situation, it is not the process of ranking within the groups that is suspect, but instead the formation of the groups itself.” Id. The same principle logically extends to the present instance in which the employer pooled employees into job codes and then determined the number of lay-offs to be made in each job code before identifying the employees to be let go.
Seagate has proffered a reason for its categorization. Operational requirements dictated that the company reduce the number of employees performing certain job functions. Thus, Seagate claims, employees were categorized according to job codes in which every employee “performed essentially the same set of tasks.” See Appellants’ App. at 315. Seagate having offered that reason, it becomes plaintiffs’ burden to show that comparisons across job codes are to similarly-situated individuals. See Furr, 82 F.3d at 988; Doan, 82 F.3d at 979. To do so, plaintiffs must show that they “essentially did the same type of work” as the employees they point to for purposes of comparison. See Fallís, 944 F.2d at 745. That showing would demonstrate that the employer’s categorization by job code was pretextual.
To meet this burden, Clark suggests that Seagate itself admitted the legitimacy of her comparison to McCartney. In its CHAPA report, Seagate lists McCartney’s job code, 1432, as “Shpg/Rec Str Clk A,” see Appellant’s App. at 172, and Clark’s job code, 1433, as “Shpg/Rec Str Clk Sr,” id. Appellants argue this shows that job code 1432 consists of higher job grades9 of the same job classification, and that both codes contain employees “performing the same duties.” Appellants’ Reply Br. at 17; see Appellants’ App. at 441. That may be the case, but we doubt that the mere similarity of job title is sufficient grounds to conclude that differential treatment of the two groups is pretextual. Cf. Fallis, 944 F.2d at 745 (to establish pretext, plaintiff geologist has burden to show that younger geologists held to lower standard had same “duties or responsibilities”). Likewise, the mere assertion, without any evidentiary support, that employees in the two codes performed the same tasks is insufficient to defeat summary judgment. See Fed.R.Civ.P. 56(e).
Clark also points to an internal Seagate memo about the RIF from Human Resources which notes: “The potential exists that within several grades of employees that have like skill sets, longer service employees may be released and lesser service employees, lesser grades, and lesser skills could be retained.” See Appellants’ App. at 581. Like the similarity of job title, this is certainly suggestive of pretext, but is insufficient without more to establish the separation of job codes 1432 and 1433 as pretextual. First, there is no indication that the above statement refers to those codes. Second, even if it does, the separation of employees with the same “skill sets” does not indicate that the separated groups perform the same functions. It may indicate that one set of employees can do the other’s jobs, but not that it actually does so. Appellants may believe that Seagate’s job coding should be by job qualification, not function performed, but it is not our place to disturb that kind of business judgment.
However, the evidence submitted by Clark does not stand alone. Critically, Jerlene Bush and Mildred Bobo, both within job code 1433, testified that at the time of the RIF, they trained two employees, Carolyn Muse and James Russell Hunter, who then replaced them in their positions. See Appellants’ App. at 496-98. Yet Hunter was placed in job code 1432, see id. at 171, and Muse in 1402, see id. at 170.10 Muse’s placement in another job code generally raises questions about the claimed functional differ-[1172]*1172enees between job codes. But Hunter was placed into the very job code that plaintiffs argue was pretextually separated from their own code for purposes of discrimination. On the basis of personal observation, two witnesses from job code 1433 testified that they trained someone to perform their jobs and that the person they trained was placed in job code 1432. That is sufficient for a reasonable jury to find Seagate’s differentiation of the two codes pretextual.
As a consequence, McCartney’s retention creates a genuine issue of material fact sufficient to preclude the entry of summary judgment against Clerk’s claim of race discrimination. However, Seagate correctly observes that Clark’s comparison to McCartney cannot support a claim of age discrimination because McCartney was 66 years old at the time of the RIF, fifteen years older than Clark. But, having established a sufficient basis to find the differentiation of job codes 1433 and 1432 pretextual, Clark can substantiate her claim of age discrimination by pointing to any retained employee in job code 1432 who is younger than she, less senior, and rated as a three 'on the CHAPA report. There is no shortage of such employees. See Appellants’ App. at 170-72. Thus, there are genuine issues of material fact that preclude the entry of summary judgment against Clerk’s claim of age discrimination.
3. Mildred Bobo, Jerlene Bush and Claudia Johnson
Like Clark, these three plaintiffs were all selected for termination from job code 1433, all of them scored three on the CHAPA report, and all three can legitimately establish age and race discrimination by pointing to younger, white employees retained in job code 1432. Like Clerk’s, therefore, their claims present genuine issues of material fact sufficient to preclude the entry of summary judgment against them.
In addition, Johnson establishes pretext by raising the inference that her final CHAPA score, which is dated June 28, 1993, see Appellants’ App. at 173, may have been manipulated. Plaintiffs submitted a number of “Employee Evaluations,” see id. at 631-764, including one for Johnson that is dated July 13, 1993, which is after the claimed date of her final CHAPA evaluation, id. at 631. This document lists Johnson’s “Last Performance Rating,” dating from December 28,1992, as a four, and states that Johnson has since “continued to perform at the same rating level.” Id. The discrepancy is startling, and not only to us.11 More than two weeks after the performance evaluation on which Seagate claims to have based its lay-off of Johnson, the company was describing, her as continuing to perform at a four rating. Johnson’s submission raises the necessary inference of pretext, and her claims therefore survive Seagate’s motion for summary judgment.12
4. Maudie Beaird
Beaird was in job code 9104, from which fifteen employees were terminated, os[1173]*1173tensibly pursuant to operational requirements. Only one employee in this code scored a two on the CHAPA report, and Beaird was therefore terminated as the thirteenth most junior 9104 employee to have a CHAPA score of three. See Appellants’ App. at 203.
Most of Beaird’s arguments for pretext are plainly without merit. For instance, she contends that her final and controlling performance appraisal was carried out by a supervisor who had discriminated against her in 1990. However, the record contains little to suggest discrimination was involved in the 1990 incident. The only evidence Beaird has in support of this claim is that the Human Resources department responded adequately to her complaints in 1990; but that does not mean the department determined discrimination was involved.
Beaird does point out the anomaly between Exhibit 53, which, for her job code; lists Eugene Fischer for termination with a score of three, see Appellants’ App. at 796, and the CHAPA report, which rates Fischer as a four, see id. at 203, and therefore determines his retention. That anomaly does not itself suggest pretext. Seagate claims to have used the latest available performance appraisals for RIF purposes, which means that final lay-offs may differ from those listed in Exhibit 53 without evidencing pretext. But Seagate’s position does not fully explain Fischer’s retention. His CHAPA rating of four is dated November 2, 1992. See id. Exhibit 53, which gives his rating as a three, was evidently compiled well after that date because it contains a three rating for Walter Johnson, which the CHAPA report dates from. June 28, 1993. See id. at 203, 796.
The anomaly therefore raises the inference that Fischer’s latest, Exhibit 53-listed score was ignored in favor of a preexisting four-rating, thus preventing his lay-off. That the stated reason for Fischer’s retention may have been pretextual does not mean, however, that Beaird’s lay-off from the same job code is also suspect. Certainly, an employer’s failure to apply objective RIF criteria to a third party may sometimes establish that that employer was not guided by the RIF criteria in an individual plaintiffs case. Pointing to a third party could show pretext if, for instance, the RIF involved a small number of people or if there are a substantial number of third parties to whom the plaintiff can point. But where, as here, a plaintiff identifies only one third party from the relevant pool of 30 employees, she fails to put forth sufficient evidence that the employer’s nondiscriminatory reason in her specific case is “unworthy of belief.” Randle, 69 F.3d at 451. Beaird’s claim is at best “colorable” and therefore does not survive summary judgment. See Anderson, 477 U.S. at 249-50, 106 S.Ct. 2505.
5. Margaret Jones
Jones was employed in job code 1032, from which a total of 116 employees were laid off by Seagate to meet operational requirements. Jones scored a three on the CHAPA report; others with that score were retained, but all had worked for Seagate for a longer period of time. Aside from pointing to retained employees with lower point scores, which, as we have noted, does not establish pretext, Jones makes two arguments in support of her claim.
First, she points to Seagate’s selective use of potential as a RIF criterion. Seagate claims to have followed the RIF criteria listed in its employee handbook, see Appellants’ App. at 219, which states unequivocally that, for RIF purposes, Seagate will take into account “operational requirements, performance and potential. Where these factors are equal, length of service will be taken into account.” Id. at 321. Yet, in identifying employees to be laid off in job code 1032, Seagate first utilized the criteria of operational requirements and performance. If those two were equal, they looked to seniority as a tie-breaker without considering potential. See id. at 323. Thus, their selection method deviated from their stated policy. That deviation disadvantaged Jones because, as a three-performer with potential, see id. at 632, she would not have been laid-off if Sea-gate had used potential to rank those in her job code who also scored three on the final CHAPA listings.
Other things being equal, that deviation might evidence pretext. Here, however, it [1174]*1174appears that Seagate effectively abandoned its stated policy of considering potential. See id. at 220-21. If uniformly applied, that shift in policy would not evidence pretext because no employer is required to follow its previously stated policies. See Jones v. Unisys Corp., 54 F.3d 624, 632 (10th Cir.1995). But, Seagate did not abandon potential altogether. There is material in the record indicating that, in some job codes, potential was factored into the RIF decision. See Appellants’ App. at 775-79. Moreover, on at least a number of occasions, potential was used where a manager could document the greater potential of a less senior employee. See id. at 776. That raises an inference, albeit not a strong one, that potential was used selectively to benefit younger employees. Cf. Mohammed v. Callaway, 698 F.2d 395, 399 (10th Cir.1983) (“disturbing procedural irregularities” may evidence pretext). Accordingly, Seagate’s decision to ignore Jones’s recorded potential constitutes limited evidence of pretext.
Jones’s second argument is based on a one-page, hand-written submission dated July 28, 1993, and headed “Rating Deviations,” which lists Jones as going from a performance grade of four, which would have resulted in her retention, to a grade of three, which did result in her termination. See id. at 627. Because the CHAPA report lists her last three evaluations as threes (or the point equivalent thereof), see id. at 167, this document raises the inference that Jones achieved a four rating that was suppressed for purposes of including her in the RIF.13
None of this evidence, when considered separately, provides a clear indication of pretext. However, we are required to consider the totality of such circumstantial evidence, see Hidalgo v. Overseas Condado Ins. Agencies, Inc., 120 F.3d 328, 338 (1st Cir.1997); Graefenhain, 827 F.2d at 19, and that does question Seagate’s proffered explanation for Jones’s termination. Jones can therefore substantiate her claims sufficiently to survive summary judgment.
Finally, there remains the question, unaddressed by the district court, of whether Jones’s claims are timely. The defendant objects that Jones’s claims are barred because they were filed with the Equal Employment Opportunity Commission (“EEOC”) more than 300 days after Seagate notified her that she was to be included in the RIF. See 29 U.S.C. §§ 626(d)(2) & 633(b); see also Aronson v. Gressly, 961 F.2d 907, 911 (10th Cir.1992) (“A timely filing with the EEOC is a prerequisite to a civil suit under ... the ADEA.”); Hulsey v. Kmart, Inc., 43 F.3d 555, 557 (10th Cir.1994) (ADEA claims accrue on date employee notified of adverse employment action); Appellant’s App. at 145 (Jones notified on August 2, 1993, that she would be terminated under RIF); id. at 133 (Jones’s charge to EEOC, dated July 19, 1994).
We agree that Jones’s claims were not filed within the stated period, but that does not necessarily mean they are time-barred. Because the timely filing of a discrimination charge with the EEOC is not a jurisdictional [1175]*1175prerequisite to a suit in federal court, it is best likened to a statute of limitations and is therefore subject to waiver, estoppel and equitable tolling. Richardson v. Frank, 975 F.2d 1433, 1435 (10th Cir.1991). The trial court made no discernible ruling on these equitable issues. We are therefore reluctant to affirm summary judgment given that no apparent evidentiary hearing was held below to determine their potential application to Jones’s case. See Wilkerson v. Siegfried Ins. Agency, Inc., 621 F.2d 1042, 1045 (10th Cir.1980); see also Delmar v. Raytheon Aircraft Corp., No. 96-1002-JTM, 1996 WL 499144, at *7 (D.Kan. Aug. 9, 1996) (denying summary judgment to employer because Tenth Circuit cases “indicate a detailed factual inquiry is necessary to determine whether equitable tolling should be applied,” requiring “[i]n all likelihood, an evidentiary hearing”). Consequently, we vacate the grant of summary judgment to Seagate on Jones’s ADEA claim, and remand to the district court to determine, in the exercise of its equitable discretion, whether Jones’s claims should be heard.
6. William Henson
Henson was employed in job code 276X. Nine employees were terminated from this section because of alleged operational requirements. As the only 276X employee to have scored a two on the CHAPA report, Henson was the first to be terminated.
Henson testified that prior to the lay-off and “during the time we got our lay-off notice,” Seagate was advertising open positions within his job code. See Appellants’ App. at 519. That claim is borne out by the record. See id. at 578 (open position in Henson’s job code that was posted on June 28, 1993, still open on July 28,1993); id. at 857-60 (August 1993 postings of at least three open positions in Henson’s job code and grade). A factfin-der could therefore legitimately conclude that Seagate was hiring into positions similar to Henson’s at the very time it claimed the elimination of positions such as Henson’s was operationally required. That conclusion is certainly sufficient to support a finding of pretext. Defendant’s reliance on Furr, 82 F.3d at 985-86, and the district court’s on Fallís, 944 F.2d at 745 n. 2, are misplaced. In both those cases, there was no evidence that the employer was hiring into similar positions at the same time that it discharged the plaintiff. Thus, as to job code 276X, Henson presents sufficient evidence of the pretextual nature of the RIF to defeat summary judgment.14
IV
A1 of the appellants have presented claims of wrongful discharge in violation of Oklahoma’s public policy against discrimination. The district court granted summary judgment to Seagate on appellants’ state law claims because it held that no state claim could lie on facts that did not also support a federal claim. Given our holding that the federal claims are generally sufficient to survive defendant’s motion for summary judgment, we cannot, for the most part, affirm summary judgment as to the state claims unless a separate basis to do so exists under state law. It does.
Appellants’ age-based claims are barred because they are based on their status rather than their actions, and because the ADEA provides an adequate remedy for the discrimination charged. See List v. Anchor Paint Mfg. Co., 910 P.2d 1011, 1014-15 (Okla.1996).
Beaird’s gender-based state claims also fail. Although an earlier ease had allowed public policy suits for racial discrimination because of the relative inadequacy of Title VII remedies, see Tate v. Browning-Ferris, Inc., 833 P.2d 1218, 1223 (Okla.1992), the Supreme Court of Oklahoma has held that post-Tate amendments to Title VII have rendered the statute adequately remedial, thus barring suits for wrongful termination in violation of Oklahoma’s public policy against gender discrimination. See Marshall v. OK [1176]*1176Rental & Leasing, Inc., 939 P.2d 1116, 1122 (Okla.1997).
In light of List and Marshall, appellants’ race-based claims must also fail. The post-Tate Title VII amendments similarly improve the remedies available for race-based claims, and Marshall must therefore bar suits for wrongful termination in violation of state public policy against racial discrimination. Cf. Cassel v. WEBCO Indus., Inc., 942 F.Supp. 1409, 1412 (N.D.Okla.1996) (“[List’s] analysis applies equally to wrongful discharge eases that could be brought pursuant to Title VII, because the remedies available under Title VII are identical to those afforded by the ADEA.”)'.
V
All the appellants, with the exception of Beaird, present sufficient evidence of pretext to establish genuine issues of material fact precluding the entry of summary judgment against their federal claims of discrimination. With regard to Beaird, the district court’s grant of summary judgment to Seagate is AFFIRMED. With regard to the other appellants, the district court’s grant of summary judgment is REVERSED as to all federal claims of discrimination, save for the claim of age discrimination brought by appellant Jones, as to which we VACATE and REMAND for further proceedings consonant with the views herein expressed. The district court’s grant of summary judgment to Seagate is AFFIRMED as to all state claims.