This wasn’t how this was supposed to end. The SEC Tournament champion wasn’t supposed to crash out of the NCAA Tournament not even a week later. The career of Jaylin Williams — Auburn’s winningest player in program history — wasn’t supposed to end his time in this uniform with the Ivy League winners perched atop media tables in celebration about 2,400 miles from home.

But No. 4 seed Auburn was upset by No. 13 seed Yale 78-76 on Friday in Spokane. It happened because Auburn finally fell victim to some Bruce Pearl warnings that hadn’t managed to bite Auburn yet.

On Friday they bit. They bit hard, and it sent Auburn packing far earlier than it expected in the NCAA Tournament.

Auburn’s hallmarks failed it. It was the anatomy of a stunning upset.

It has relied on an efficient offense that shared the ball well. Auburn spent much of the season in the top 10 nationally for assists and assist-to-turnover ratio. It entered Friday as such — eighth in the nation in assist-to-turnover ratio (1.70) and eighth in assists per game (18).

It wasn’t there against Yale. Auburn committed more turnovers (14) than it had assists (11). Six of those turnovers game in the final six minutes. Auburn had nine second half turnovers against two for Yale.

For this team, that’s not a formula to win.

Nor is missing four crucial free throws in the final minute. Guard Denver Jones missed the front end of a 1-and-1 with 46 seconds left. Guard Tre Donaldson missed both free throws with six seconds left and the game still in reach.

Winning in March requires free throw shooting. Because 26 of Auburn’s 27 wins came by double-digits, Auburn was rarely in a position to make key free throws. Auburn’s win over Mississippi State in the SEC Tournament is the only time Auburn has successfully done that this season. Chad Baker-Mazara missed a game-tying free throw with 12 seconds left in Tuscaloosa in Auburn’s Jan. 24 loss to Alabama.

This Auburn team cruised through so much of the season, it didn’t have experience in a close game where clutch shots were required.

Auburn has a 75.2% free throw make rate this season. It went 15-22 against Yale, with all the brutal misses coming late.

But those are the anomalies.

Two other areas that Pearl has warned about finally got Auburn: second-half defense and fouls.

“The defense was in front of our bench in the first half,” Pearl said on Nov. 21 after beating Alabama A&M. “We were obviously flying around and doing what we needed to do, and once again, our second half defense dropped off.”

It was one of many games where Pearl sounded an alarm. Auburn’s defense was good and got better as the year went on. Auburn is a top-five team in defensive efficiency per KenPom. But the second-half defense lapsed throughout the year.

“That second half team couldn’t win an SEC game,” Pearl said after the Alabama A&M game. “Not a one.”

Auburn saw that second half team that lost the second half to Alabama A&M at times throughout SEC play. But Auburn’s average scoring margin is 15.3 points, the seventh most in America.

Auburn was often up by so much at halftime that it could lapse in the second half and it wouldn’t matter.

Second half defense never bit Auburn because it wasn’t playing many close games.

Until Friday.

“I think our second half defense wasn’t as good,” Pearl said after losing to Yale. “We didn’t turn ‘em over as much. We succumbed to fatigue a little bit. They made a bunch of shots off of us, and we turned the ball over too much in the second half to win.”

Auburn was outscored 44-35 in the second half and 20-8 over the final 7:27. Auburn led by 10 points with 7:27 left to play.

Yale shot 52% from the field in the second half after shooting 40.7% in the first.

Yale equaled Auburn’s points in the paint in the second half with 12 for each team. It had 13 fast break points in the second half to Auburn’s five.

Of those final 20 points in the 7:27, half of them came on Yale free throws.

Pearl was clearly frustrated at the officiating throughout the game. He disagreed with the decision to throw out Chad Baker-Mazara on a Flagrant 2 foul. He thought it was just a Flagrant 1. He said frequently in his press conference that he planned to go back and look at the film to see just how much contact was and was not called.

What Pearl didn’t discuss is the data that finally caught up to Auburn. The Tigers are among the highest-fouling teams in America. Auburn commits 19.2 fouls per game. That’s 322nd out of 351 teams. No matter what Pearl thinks of the officiating against Yale, season-long numbers show a consistent fault.

Fouls are by far Auburn’s biggest statistical detriment. It’s the only significant category Auburn is not in the top 140 teams in.

For all the depth Auburn has, foul trouble has never been a serious issue for this team. But the amount of times it sends its opponent to the free throw line can be.

In no previous game did it cost Auburn like this.

Auburn was called for 25 fouls against Yale. Yale shot 31 free throws and made 21 of them. It’s the same percentage from the line (68%) that Auburn shot, but on nine more attempts. Of the 31 attempts for Yale, 20 came in the second half.

There’s a formula to win in March. It takes clean basketball, it takes defense.

Auburn had been so good in those areas all season. It’s why it was a trendy pick to make a run in the NCAA Tournament.

Its sudden failure in Spokane in what it had done so well all season led to Auburn’s sudden exit.

Matt Cohen covers sports for AL.com. You can follow him on X at @Matt_Cohen_ or email him at [email protected]