Ok I made a mistake. The game harness was doing a lot of heavy lifting for both models by preparing optimal options for Jev/Haiku to pick from, given a game state. If I change the harness to provide only game rules and game state, and only allow Jev to decide the control buttons (left/right/rotate/drop), it pretty much becomes useless.

Tony Dinh@tdinh_me2d ago

Tetris battle: Jev vs Claude Haiku 4.5 Both compete in REAL TIME. This means both SPEED and INTELLIGENCE matter. (Link to try it yourself below)