Coming into the 2024 game I didn't put too much thought into the following..
OK State was the ONLY team on the 2024 schedule that had specifically planned and beat Retzlaff before.
I think Gundy playing pretty much the same BYU ( although improved ) team from 2023 and him having a lot of the same weapons he had that allowed him to win in 2023 allowed him the confidence not only for himself but also his team coming into the game.
OK State 2023 XP and keeping somw of their main pieces from their 2023 team intact made them uniquely more prepared for BYU than any other ( Kansas could qualify too ) teams on our schedule which is what allowed them to almost win the game.