A hot streak is when you're making more shots than the game expects you to. The game keeps a running tally during the game. Every make pushes it up, every miss pulls it down. Tough makes push it up more than easy ones. When that tally is high, your green window gets smaller on CONTESTED shots. Wide open shots are barely touched, 5% at most. Missing brings it back down. The game tracks makes against how likely each shot was, so a contested make counts for more than a wide-open one. So if your contested jumper feels tighter after you hit a few in a row, that's why. The Oct 1 update made that shrink a little weaker.