Encountered a y10 guy who plays hyper-aggressively, and prefers quick paced open games.
Eventually got him into an inescapable checkmate by playing a slow, tight game.
Also encountered a y9 gut who I can play risky against because his play style is slow, allowing me to pull off sacrifices that return massive advantages.
And y11 guy who I just play normally against, opting for positional advantages.
Take away lesson:
The psychology and biases of your opponent matters just as much as the skill set of your opponent.