STILLWATER, Okla. — One of the most dismal seasons in recent BYU football history ended Saturday night in the rain and cold of half-empty Boone Pickens Stadium in one of the worst ways possible, as the Cougars blew an 18-point halftime lead and fell 40-34 in double overtime to the Big 12 championship-game-bound Oklahoma State Cowboys.

If nothing else, however, the final game of the 5-7 Cougars’ first season in the Big 12 showed that just maybe there are brighter days ahead.

“BYU did a good job. They had a lot of different things. They could put all their chips out, no matter what their hand was. ... They did the right thing and were trying to win at all costs.” — Oklahoma State coach Mike Gundy

“We did everything we could,” BYU coach Kalani Sitake said outside a somber, disconsolate BYU locker room after the nearly four-hour game ended. “Just came down to the end. Mistakes cost us. But the guys fought hard. I appreciate how hard they fought. We just didn’t make enough plays, especially in the second half.”

Only when tight end Isaac Rex was stripped of the football on BYU’s second offensive play of the second overtime could a team favored to win by 17 points celebrate, and celebrate the Cowboys did — twice. The play was reviewed after Trey Rucker’s strip and fumble recovery, and officials ruled that Rex wasn’t down before the ball came out.

Ball game.

And what a game it was, the third largest comeback in OSU history. The No. 20 Cowboys will face No. 7 Texas in the Big 12 championship game, while the Cougars will miss a bowl game for just the second time in 19 seasons.

“We threw the playbook at them,” Sitake said.

Indeed, the Cougars tried an onside kick, a fake punt, and the usual assortment of jet sweeps and screens, before getting much too conservative in the second half, playing not to lose after putting together one of their best halves in years in the opening 30 minutes, taking a 24-6 lead at the break.

It was eerily reminiscent of the 2018 loss to Utah when the Cougars had a 27-7 lead in the third quarter, tightened up and lost 35-27.

While the Cowboys escaped in a game that most pundits figured they would win easily, the Cougars were left wondering what might have been. For instance, what if BYU hadn’t punted on fourth-and-1 from their 35 with 5:34 left in the game and clinging to a 24-21 lead?

Oklahoma State promptly drove 80 yards in 11 plays, converting a huge fourth-and-3 by a yard at its 42, and took a 27-24 lead with 53 seconds remaining. BYU offensive lineman Simi Moala blocked the PAT to keep it a 3-point game.

“I wanted to go for it. I felt like we were closer on the spot, maybe a half a yard closer (after Aidan Robbins’ third-down run),” Sitake said. “And the problem is that if you go for it they are right away in field goal territory. We talked about it as a staff, decided to punt the ball and boomed a punt that went all the way into the end zone. … So it wasn’t that decision that lost us the game. It was the drive that we gave up.”

Really, it was puckering up in the second half that cost the Cougars the game. As he left the field at halftime and his team ahead by 16, Sitake said they “got back to our roots” and pulled out all the stops. But they stopped doing that in the second half, while sticking with quarterback Jake Retzlaff when it was obvious he was struggling to make even routine throws.

“BYU did a good job. They had a lot of different things,” admitted OSU coach Mike Gundy. “They could put all their chips out, no matter what their hand was. ... They did the right thing and were trying to win at all costs.”

Then they shot off their own feet. Pistols up had a whole new meaning. The Cougars stopped firing away.

After netting 202 yards in the first half, they had just 100 in the second 30 minutes. They punted the first six times they had the ball in the second half.

“I will have to watch the film,” Sitake said of the sputtering in the second half. “Obviously we would like to see more points on the board, because if we get more production in the second half it will help us out, even sustain some drives so that we can get some relief to the defense. … The turnovers cost us. That’s a problem. We have to take care of the football.”

Actually, the Cougars played turnover-free in the second half — until Rex’s fumble in the second overtime.

“I think we could have found a way to win the game in different areas, and it doesn’t come down to one guy making a mistake,” Sitake said. “I wish it hadn’t come down to Isaac (with) the ball and fumbling the ball.”

Retzlaff finished 14 of 30 for 161 yards and ran 11 times for 15 net yards, and two touchdowns, including a 6-yard scamper in the first OT.

Why didn’t coaches turn to the veteran Kedon Slovis, who they said was available to play?

“Yeah, I think that was (part of) the thought process,” Sitake said. “Kedon hasn’t been 100% yet. You are putting someone at risk. If he gets banged up. I think he … has a career at the next level. He throws well, and when he is healthy he is really good. It would be hard for us to make that move and put that much pressure on him. I don’t think we felt that was the right move at that time.

“But we considered it,” Sitake continued. “I know Kedon was ready to go and wanted to be in there.”

3 takeaways from BYU’s season-ending loss to Oklahoma State
Highlights, key plays and photos from BYU’s double-overtime loss to Oklahoma State

The first overtime almost didn’t happen. BYU’s Will Ferrin booted a 48-yard field goal with no time remaining in regulation, that after fourth-time starter Retzlaff had driven the Cougars 44 yards in 10 plays in 53 seconds. 

“We was right there. We had the opportunity. It was just one of those games where we came out clicking, but we just didn’t make the big plays down the stretch to finish the game,” said BYU cornerback Eddie Heckard, who had two interceptions, including one he returned 13 yards to give the Cougars a 14-6 lead in the second quarter.

Any momentum the Cougars may have garnered in taking the 24-6 halftime lead was squandered away when they went three-and-out on their first possession of the second half, and Ryan Rehkow’s punt traveled just 29 yards.

Oklahoma State got back in it quickly, driving 43 yards in four plays and cashing in with a 2-yard touchdown run by Ollie Gordon, the nation’s leading rusher who finished with 166 yards and five touchdowns on 34 carries.

Some of Gordon’s TD runs were of the eye-popping variety.

“He really went to work,” said BYU defensive end Tyler Batty, who caught a 36-yard pass from punter Ryan Rehkow on a brilliant fake-punt play in the first half when the Cougars were throwing caution to the wind. “We knew that coming in, that he was a phenomenal back.”

Batty said the defense, which held OSU to 169 yards and 4.3 yards per play in the second half, made some adjustments in the second half when OSU’s quick-passing game got going enough to open up more opportunities for Gordon. 

But the Cowboys were a step ahead the entire second half.

In the second overtime, OSU went first, took advantage of an iffy defensive pass interference call, and went ahead 40-34 on Gordon’s fifth TD run.

Then came the fateful play on second-and-2, Rex caught the 4-yard pass, took a few steps, then lost the ball a split second before his knee hit the ground.

And BYU’s first season in the Big 12 was over.

“The guys didn’t quit their fight,” Sitake said. “There were some big losses on the scoreboard to West Virginia and Iowa State, but the guys didn’t quit. … I can build off guys that work hard and want to be here and want to fight.”

He will just have to wait until next season.