The tvOS question was whether losing JavaScriptCore's JIT would blow the frame budget, and guessing at it was cheaper to settle than to argue: run the same self-play fight twice, once under JSC_useJIT=0. It costs 2.8-3.1ms of 16.67 either way. The frame is spent crossing the native bridge, not executing JavaScript, so the JIT has little to take away. OSKIEWAR_PERF=1 prints it; OSKIEWAR_SELFPLAY=1 measures a real fight, because a title screen simulates almost nothing.