Removing PER From Rainbow DQN Set a New Snake AI World Record

Greetings all! Quick context: this is part of an ongoing series where I'm building Rainbow DQN one component at a time on Snake and measuring what each piece actually does. The first post covered the encoding, the second covered a memory optimisation. This one is about the finding I've been teasing: which Rainbow component hurts performance on Snake. The answer is Prioritised Experience Replay (PER). Removing it from Rainbow DQN didn't just match performance. It set a new world record of 153 on