If you're up two, you are never suppose to foul. If you are up 3, it depends on how many seconds are left, who's on the court, how many time outs, who's in foul trouble, where you are playing, etc. A smart coach would analyze all of this to determine yes or no with the limited time you have to make this decision. I'll try to break it down by the recent heartbreakers:
-Clippers up 3 with 9 secs left, Blazers ball
-Foul: Blazers can potentially make both and foul the Clippers hoping they will not make both. So for the Clippers, you are back to square one by being up 3 with a few secs ran off, or you can actually lose the game if you miss a FT and the Blazers hit a game winner at the end of regulation.
-No Foul: Hope for a missed shot with good defense or it goes into OT where Clippers actually had the momentum after such a comeback.
-IMO, Doc made the right decision because there was 9 secs left. We just didn't get the right defense and didn't do so well in OT.
-Clippers up 2 with 6 secs left, Nuggets ball
-Foul: HELL NO! You can't just hand them two free shots to try and tie the game. Clippers would then have to make the game winner or go into OT as the away team.
-No Foul: You just have to trust your defense and hope for a miss to win the game. Unfortunately, Foye made a hell of a 3 pt shot to win the game. You really can't defend that shot any much better or else you foul them and they get 3 FTs.
I'm no coach, but I hope you guys can see what's going on in a coach's head during that decision process. I give them props because sometimes they don't even have a timeout to anaylze it out, they just call it from the sidelines which can just be a few seconds. Anyways, just because you lose the game doesn't mean the coach made the wrong decision. As long as you play the statistics, you're going to win more games than lose.