This has actually been very unclear, but the player Hot Streak has been in the game for a while. On XBox, press the right stick down to see how hot your players are. Grey is neutral, shades of blue mean they're doing bad (The darker the shade the worse they are) and orange and red mean the player is 'on fire.' They get these levels by doing well or struggling, and then cause your player to continue to play like that. So if a QB throws 2 picks in a row, he will be blue and his ratings take a hit. You either want to pull him or dosimeter safe, conservative passes to boost his confidence. If you try tricky passes with the QB, his accuracy will likely be off.