I know that for Guaranteed Starts... I think it's 80% of the games the player will expect to start without their WE dropping.

For Guaranteed Minutes does it work the same way? Does the player expect to hit the guaranteed minimum in 80% of games... or will be he be happy as long as his average amounts at or above the promised number of minutes?

It is ROUGHLY 80 percent of the minutes promised. Some players want higher, some won't complain til below 75 percent. But it is the average over the season not the percent of games. So you could promise 10, play the kid 19 minutes I half your games and 1 minute in the other half and be in the clear as that would average 10.

Thank you, rednu. That's very helpful.

Between 3 different recruits, I promised a total of 50 minutes. 2 are starting... so I'm mostly worried about keeping the 3rd happy. Should be interesting!

Agreed with what rednu said. 

I've had some players who wanted about 90% of the promised minutes.  My guess is that's about where the upper limit is (90).  80% seems to be fine for the majority in my experience.

One other thing to keep in mind (since it hasn't been said) -- just like promised starts the average is taken over just the 26 regular season games. Exhibition and conference tournament/postseason tournament games don't factor in, so if he's happy after game 26, you can sit him for the postseason and he'll still be happy. On the flip side, a kid who sits out a game for non-injury reasons will still count that game toward his calculation of whether you're playing him a suitable percentage of the promised amount (so you can't play a kid you've promised 10 minutes to for 12 minutes in the season opener, sit him the next 25 games and expect him to be happy...that used to work, but they plugged that hole)