Sports thrive on statistics, and the N.F.L. scouting combine produces no shortage of them. Players’ official measurements in drills like the 40-yard dash, vertical jump and bench press help determine how high they will be drafted in April.

In recent years, the supposedly confidential results of the Wonderlic test, a 50-question I.Q. exam administered to players at the combine, have regularly leaked to the public, giving observers fodder to try to quantify the “smarts” of future pros based on an exam that has long been criticized for racial and socioeconomic biases. No statistically significant correlation between a player’s Wonderlic score and his on-field performance has ever been documented.

As part of what Troy Vincent, the league’s executive vice president of football operations, called “an overall audit of all of the assessments” taken at the combine, the N.F.L. announced in January that it would stop administering the test. “Frankly, it’s been an outdated process,” Vincent said.

Teams will still have the option of using the test if they choose, though the league could institute a complete ban after this year’s combine. “We didn’t want to be too disruptive,” Vincent said.

But the league’s efforts to phase out the Wonderlic have not stopped N.F.L. teams from trying to meaningfully assess what’s in a prospective player’s heart and head ahead of the draft, and they are employing a bevy of other tools, tests and exams in an attempt to do so.

E.F. Wonderlic invented his eponymous I.Q. evaluation in 1936 as a graduate student at Northwestern University, and it made national news in 1971, when the Supreme Court ruled that the Duke Power Company’s use of the test as a basis for promotion violated the Civil Rights Act, which forbids race-based discrimination in employment. But the Wonderlic nevertheless caught on in the N.F.L. in the mid-1970s, when Tom Landry, then the head coach of the Dallas Cowboys, adopted it as his preferred measure of on-field intelligence. The rest of the league quickly followed suit.

Dr. Derrick White, a professor of history, African American and Africana Studies at the University of Kentucky, said the test’s biases likely aided in “stacking,” or placing players in certain positions according to racial stereotypes.

“A lot of the discussion only gets at the quarterback position,” White said, “but in the 1970s, middle linebacker, safety, center — those were all the quote-unquote ‘thinking positions.’ The Wonderlic, I suspect, was testing to keep Black folks out of those positions.”

A 2011 study by two Cal State Fullerton economics professors found that an increase from the 25th to the 75th percentile in a Wonderlic score correlated to a rise of more than 14 spots in draft position for a white player. For a Black player, the gain was less than half that.

Increasingly over the last decade, the N.F.L. and its teams have turned to other assessments that claim to gauge how quickly players pick up football-specific concepts and assess behavioral tendencies, all in an attempt to discern if they’ll fit in with the pros. At the 2013 combine, the league debuted the Player Assessment Test, a computerized test created by Cyrus Mehri of the Fritz Pollard Alliance that measures attributes like aggressiveness alongside cognitive traits.

To scout players themselves, teams have also leaned on consultants with proprietary tests that claim, with varying support, to evaluate players’ sport-specific intellectual ability. The Athletic Intelligence Quotient emphasizes spatial awareness and fast-paced decision-making, the Troutwine Athletic Profile rates a dozen “performance traits” such as composure and grit, and Human Resource Tactics uses testing that purports to gauge, among other things, an athlete’s love of the game.

Mark Aoyagi, a director of sport and performance psychology at the University of Denver and a former draft adviser to an N.F.L. team, views the testing boom with skepticism. Aside from the A.I.Q. and the Test of Attentional and Interpersonal Style, the tests have not been subject to peer review in leading scientific journals, leading to doubts of their efficacy.

“A test that does not have scientific validity is no different than me playing tic-tac-toe with them and saying, ‘This must predict something about their future,’” Aoyagi said.

In his consulting role, Aoyagi employed the A.I.Q. and T.A.I.S. to evaluate draft prospects, before conducting interviews with them. “We call that triangulation — the data from the A.I.Q. and T.A.I.S. and your own observational data,” Aoyagi said.

Daniel Jeremiah, a former N.F.L. scout who now works as a draft analyst for the N.F.L. Network, emphasized that no one test can provide conclusive insight into whether a player will be able to adapt to being a professional. Talking to coaches and teammates, scouring film and spending as much time with the prospect as possible, he said, are all necessary evaluation tools. “It’s the biggest challenge for scouts now, finding out how they’ve dealt with stuff in terms of toughness, mentally and physically,” Jeremiah said.

Taking that approach could help teams make educated decisions on some of the highest-rated players who have entered this year’s draft. Six months ago, Oregon defensive lineman Kayvon Thibodeaux’s burst, flexibility and tackling earned him a reputation as a can’t-miss prospect. But since completing his junior season, in which he recorded a career-high 49 tackles, Thibodeaux has dropped in draft projections as scouts and analysts have questioned his commitment to the game.

While gauging aptitude has been the domain of tests, personality has been left largely to sometimes contentious interviews with teams. In 2010, Miami Dolphins General Manager Jeff Ireland asked wide receiver Dez Bryant if his mother was a prostitute, a question Ireland later apologized for, though he received no league punishment. It was a particularly egregious example of a common practice — what the former N.F.L. scout Jim Nagy called an “interrogation style to get a rise out of a player and see how he will respond.” In such circumstances, players can be called to walk an impossibly fine line: They must show passion without being labeled a hothead, yet stay cool without seeming dispassionate.

Sarah Jackson, an Atlanta-based agent, rehearses answers to just this sort of question with players she represents. “If they talk about your mom, what are you going to say?” Jackson asks. “If you have a challenging relationship with your family and they start poking at that, how are you going to reply?”

Jeremiah, the former N.F.L. scout, said the Thibodeaux conversation brought to mind Haloti Ngata, whom he scouted when he worked for the Baltimore Ravens in 2006. “There were a lot of questions about his motor,” Jeremiah said, but the Ravens staff found good reason for the occasional tired play: The 340-pound defensive tackle played an astronomical 90-some snaps a game and took on extra duties on special-teams units. “It’s not humanly possible for him to go hard all the time,” Jeremiah said.

Baltimore selected Ngata 12th overall; he retired in 2019 as a five-time Pro Bowler.