X (Q) punches with the left hand and Y (E) with the right. The hand rides the input as PunchL — the striking arm is also the hitbox, so it has to be part of what netplay and replays carry (one more bit at the end of the mask; older replays decode unchanged). startMelee strikes with that hand and the pose names it. X+Y together is the 2D fight's grab; A, X and Y each wait two samples for a chord partner. The online challenger sampled the raw pad, so the host read its X as the old bubble; it now sends the translated buttons. Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>