In season 2, episode 10 "Smile, Bitches!", Zach gets angry at Bryce during the baseball game.
Knowing the tension between the two of them it's not really surprising. But for a non-American / no baseball fan I'm a bit startled by why this was the trigger. Zach is the catcher (?) and pointing three fingers towards the ground. Bryce throws, Zach catches, it's a strike for the other team. I suppose that's a good thing.
Why is Zach angry at Bryce playing not team-focused when throwing a ball?