If the position in the diagram below looks familiar, it's because you followed the recent 2012 Anand - Gelfand World Championship match. Game 12 was the last game at standard time controls in a match tied at +1-1=9. After capturing a Bishop on e7, Anand offered a draw even though he had a Pawn more and a large time advantage on the clock. Gelfand accepted the draw and went on to lose the match in rapidplay tiebreaks. Anand's draw offer left the spectators bewildered. Here's how Chessbase.com described it.
Though his winning chances were minimal, to be fair, his opponent was down to sixteen minutes to make eighteen moves, and it was entirely riskless to press on and see what happened. Vishy’s justification in the post-game conference was that it was equal and simplified, but that is hardly the question. The real question is: where was the harm in playing on? The only certainty is that he will not win if he does not even try. [...] When the players finally shook hands, Kramnik, expert commentator of the day at the official site, was fairly shocked. World Championship G12 – Draw in 22 moves
I was watching Kramnik's commentary at the time of the draw offer and agree that he was 'fairly shocked', even annoyed, as were most post-game commentators. No one, however, explained how White should continue, which left me curious about the likely conclusion to the endgame. The diagram shows the position which would have occurred had Black played the automatic recapture of the Bishop.
Anand - Gelfand, 2012 WCC match, game 12
After 22...Kxe7 (not played)
Chessgames.com's live, written coverage of the game is available on its site. The moment when the draw was agreed is on page 19 of the commentary: Viswanathan Anand vs Boris Gelfand (2012). Despite heavy criticism of the game and the match, there was no concrete analysis of the final position. The only clue I could find was 'Shipov gives a sharp line explaining Anand's draw'. As luck would have it, Shipov's Russian analysis is translated on DanaMackenzie.com: Anand – Gelfand Game 12: The Battle Continues.
22.Bxe7 and here Anand somewhat unexpectedly OFFERED A DRAW, which Gelfand quickly accepted. A possible continuation was 22...Kxe7 23.Nd2 a4 24.Rc7+ Kf8! 25.b4 a3! and Black’s counterplay is not bad. What can I say? It’s easy to understand the champion’s decision. One can’t say that playing for a win in the final position would be free of risk. Quite the opposite!
The game just completed must be considered disappointing for Anand. In the opening he achieved a promising position and an hour time advantage -- what more could you possibly want? Gelfand held himself together like a champion with a fine sense of psychology. He correctly returned the extra pawn, and then provoked his opponent, tempted him with another pawn sacrifice, seized the initiative and escaped with only a mild scare.
Which assessment is correct, Chessbase.com's 'entirely riskless to press on', or Shipov's 'One can’t say that playing for a win in the final position would be free of risk. Quite the opposite'? I fed the position to an engine, which offered the same continuation given by Shipov, minus the '!'. After 25...a3, it suggested 26.Nc4, when in all subsequent continuations White must give up the extra Pawn, leaving him with no winning chances. The problem with White's position is the isolated Pawn on d3. Black has sufficient pressure to keep White tied up defending it. If White's King were on f1 instead of g1, White would have better chances.
Objectively then, the position is a draw. Anand must have determined the same and decided that he had better chances in the forthcoming tiebreak games. Are world class players obliged to reveal their thinking to the public by playing the game out? If so, the rules should mandate it. This is easily done by eliminating the draw offer as a valid variation. You can't blame the players for using the legitimate tools at their disposal.