public Color performMcRun(boolean mercy, Board originalBoard) {
player.descend(this);
Color winner;
if (originalBoard.getPasses() == 2) {
winner = scorer.winner();
} else {
winner = playout(mercy);
}
player.updateTree(winner, this);
playoutsCompleted++;
return winner;
}
/**
* Plays moves to the end of the game and returns the winner: BLACK, WHITE, or (in rare event of a
* tie or a playout canceled because it hits the maximum number of moves) VACANT.
*
* @param mercy True if we should abandon the playout when one color has many more stones than the
* other.
*/
public Color playout(boolean mercy) {
do {
if (board.getTurn() >= coords.getMaxMovesPerGame()) {
// Playout ran out of moves, probably due to superko
return VACANT;
}
if (board.getPasses() < 2) {
selectAndPlayOneMove();
}
if (board.getPasses() >= 2) {
// Game ended
return scorer.winner();
}
final Color mercyWinner = mercyObserver.mercyWinner();
if (mercy && mercyWinner != null) {
// One player has far more stones on the board
return mercyWinner;
}
} while (true);
}