He tried a number of different combinations, starting the game with Nick Collison and then going small with Kevin Durant at the 4 and super-small with KD at the 5. Not all of them worked, but it was a refreshing change of pace for a coach who was always been afraid to alter his line-ups and make adjustments over the course of a seven-game series. However, with the Spurs offense clicking on all cylinders, Brooks doesn't have too much time to find the right answers.
We will see whether he will continue to experiment in Game 2 or return to his usual pattern of stubbornly refusing to confront reality. He needs Kendrick Perkins to counter Tim Duncan, but the other three veterans he has stuck with to the very end - Derek Fisher, Caron Butler and Thabo Sefolosha - are once again offering very little and dragging the Thunder down. If there's an answer in OKC besides the obvious (play Reggie Jackson and Jeremy Lamb more), it comes from another young player who has never really earned Brooks trust - Perry Jones 3.
PJ3 is the closest approximation of Ibaka's skill-set on their roster - he's 6'11 235 with a 7'2 wingspan, extremely athletic and he can knock down corner 3's. He fell out of the rotation over the course of the season, but he played 62 games in the regular season and was a huge factor in both their games against the Miami Heat this season. He's the best of both worlds for Brooks line-up dilemma - he spreads the floor on offense and gives them size on defense.
Part of the problems with the small-ball line-ups with KD at the 4 or the 5 is that Brooks is sacrificing any gains in athleticism by putting Caron and/or Fish on the floor. Those guys are older than everyone in the Spurs rotation except Duncan and Ginobili and they are pretty much useless defensively. Fisher was able to make some 3's in Game 1 but that was the definition of a broken clock being right twice a day - he's shooting 27% from 3 in the playoffs, if you hoist enough shots, eventually some have to go in.
PJ3 gives them a ton of line-up flexibility - he can play at the 5, 4 or 3 and he shot 36% from the 3 in the regular season. He's a much bigger body for post defense than KD and he's way more of an offensive threat than Perkins or Collison. He hasn't played much over the course of his first two seasons in the NBA, but that shouldn't stop a coach from going with what he thinks is the best line-up - look at how Popovich used Aaron Baynes in Game 1. It isn't that complicated. If you miss what Ibaka is bringing to the floor, use the player on your roster who most closely replicates his skill-set.