Buzzer Beater is gullible. Whatever the setting is at the time of the training update, is what will be used. When a game is played, BB simply records the minutes played at each position and doesn't relate that to training. So if your player has 24 minutes at PG and 30 minutes at SG; it isn't until the training update that BB figures out whether this was helpful for training (eg if your setting on Friday is JS for PG/SG he will get training based on 48 minutes; if it is JS for SG, he will get training based on 30 minutes; and if it is SB for C, he will get no training).