Combining Masters of the Endgame, where I identified a number of players well known for their superior endgame play, with Endgame Storyboard, where I worked out a technique for discussing endgames on this blog, the image below is a slight adaptation of the one I used in the 'Storyboard' post. The game is the fourth from a 1974 Candidates Match and can be found on Chessgames.com at Anatoly Karpov vs Lev Polugaevsky; Moscow cqf 1974.
On top of the references in the 'Masters of the Endgame' post, I found the game annotated in collections by Botvinnik, R.Byrne, and Mednis. The differences in the notes of the three GMs convinced me that this game was not as straightforward as I thought at first.
Looking at the first and last positions in the storyboard, everyone agrees that Polugaevsky was better after 22...Rxe6, while Karpov was winning after 45...Re5. In fact, he was already winning after 41.b5, the sealed move, where Botvinnik commented, 'The adjournment analysis of this position can not have brought Black any comfort.' What happened in the ~20 moves after 22...Rxe6?
After 25...Be3, Karpov's 26.Bxe3 was given a '?' by the two Americans. Mednis noted, 'Rather incomprehensible from as fine a strategist as Karpov'. Botvinnik agreed with the others that 26.Bxg4 was 'probably better' than the move played, but gave Karpov the benefit of the doubt, saying, 'Karpov does not want to part with his Bishop, which protects his e-Pawn so effectively.' Karpov was known for his stubborn defense of inferior positions, often converting them to draws or even wins.
The tide began to turn with 30.Rd3. Here Black played 30...g5, the start of a series of inferior moves. Mednis tried to show that Black had a forced win of a Pawn, but the engines do not confirm his analysis. After 31.h3 h5 32.Nd5, Black went awry with 32...Nxd5, when 33.Rxd5 left the Black Kingside Pawns vulnerable and initiated a plan of advancing the White Queenside Pawns.
Polugaevsky's last chance was after 36.R1d4. He played 36...f6, hemming in his own Rook and missing the chance to stop White's advance with 36...b6. Karpov didn't give Black a second chance and played 37.a5. I often see this type of Pawn move in Karpov's games, where he both furthers his own plan and blocks his opponent's best defense.
It took only a few weak moves by Polugaevsky to give Karpov his first win in the Candidate series on the way to becoming World Champion. The eighth game in the same match was given by several commentators as another example of Karpov's endgame prowess.