Anand, not expecting the blunder, replied with 26... a4?? in less than a minute. He, too, saw the missed tactic immediately after making his move. Carlsen made no further mistakes and converted his advantage into a win. Sometimes players, including strong grandmasters, resign in a position in which they are actually winning, not losing. Chess historian Tim Krabbé calls this kind of mistake "the ultimate blunder". In this 1902 game between Ignatz von Popiel and Georg Marco, the black bishop on d4 is pinned to the rook on d7, and there are no additional friendly pieces to come to its defense. Seeing no way to save his bishop, black resigned, missing 36... Bg1!, threatening Qxh2# and leaving no way for white to save both his queen and rook while staving off checkmate. Tim Krabbe called this the "earliest, most famous, and clearest example" of resigning with a winning position. In this game played in Budapest in 1955, Black saw that White's c3-knight is stopping Rd1#. Therefore Black played 19...Qxa2+??, deflecting the knight. White agreed, and resigned. Both players overlooked that after 20. Nxa2 Rd1+, the deflected knight can still stop the mate with 21.Nc1. Black is ahead by lots of material but White has a forced win. Correct is 58.Qg8+ winning the bishop (since 58...Bf7 59.Qd8 leaves two mate threats which cannot be parried at the same time). However, White played 58.Kd8?? (threatening 59.Qe7#), thinking that it won on the spot. Miguel agreed, and resigned. However, both players overlooked the defense 58...Rxg4 winning more material and the game. 58...Rxg4 also saved Black against mate. In fact, White doesn't have any more Qc8+ which forced mate.