Determines which player's state to use for: score (state_score_player_1_low vs state_score_player_2_low), lives (state_lives_player_1 vs state_lives_player_2), bridge progress (state_bridge_player_1 vs state_bridge_player_2). Players alternate turns in two-player mode, switching when one dies if the other has lives. Colors: P1=yellow ($06), P2=cyan ($05).