It's funny that you started a thread on this... I was thinking about doing so as well.
I play on pro level with real ft % set at 50, and I noticed something:
When I let the players go through their free throw shooting ROUTINE I shoot a VERY HIGH percentage!!
BUT, when I hurry through that and skip the routines and just shoot them, my percentage drops a LOT.
So I'm thinking about ramping up the difficulty to 75 and see what happens. I've learned to be patient in this game: run plays, let the screen shots take place, and just relax and enjoy the game. I've upped my quarter length to 12 minutes, but run more plays. I only mention this because I am strongly believing that the FT routine might be connected to the percentage.
...but then again.
