In the NFL and the NBA, final salary cap numbers can fluctuate.

You have to assume that your bottom 8 guys(those you drop to get to 27) will, on average, be equal to every other teams bottom 8. So if you are under the cap with 35 players, 9 out of 10 times you will be under the cap with 27 players.

If every team has 35 players, and the ave. is 95, with a cap 117, then you can assume that when you drop your 8, the new cap will be approx 4-6 points less. So if you have a PB value of 120, figure you need to get down to around 112 to be safe. Look at 8 guys you might drop, and if you are still too high, you may need to trade one of your higher PB value guys for a good prospect.

Remember that less than 10% of the teams will even have to worry about this.

Hope that helps.