At first glance, 53. g4+ <Kxg4> looks dangerous because Black's king is in a net. But probably he can wriggle out again: 53. g4+ Kxg4 54. Rg3+ Kf5 55. Rg5+ Kf4 56. Bb2? <Bxf2!>.

So there is probably no quick king hunt, but White still looks winning after 53. g4+ Kxg4 54. Rg3+ Kf5 55. Rg5+ Kf4 56. Rxg6 Bd4 57. Rc6, etc.

After 53. g4+ Kxg4, White probably plays <54. Rd7>. The point is if 54...Nc5 now 55. Rd5 and Black's knight gets in the way of the rook, preventing the counter-attack with ...Rc2. Now Black's king really is in a dangerous net and White will probably pick up some more material in the near future.

54...Nd8 in that line looks even worse. At the very least, White has 55. Nf6+ Kf5 56. Nd5 trapping the bishop (56...Bd4 57. Ne7+ Ke6 58. Rxd4).

To take the tree metaphor, it is as if the e pawn of black - that pawn island of one is like a friendly little tree to the White's position, celebrating the warmth and comfort of that e4 square - as a basis for great operations.

Harry Golombek, who was Match Judge, but also made no bones about his preference for Botvinnik, did a real hit on this game, which Clarke may have been influenced by:

<GOLOMBEK: "The nineteenth game had been adjourned in a dead-won position for Petrosian. The general assumption was that it would last only another half a dozen moves. Had he had this position against Smyslov, it was said, Botvinnik would have resigned without resuming play. Flohr told his wile he would be back in half an hour in time to help entertain guests to a small party. I harboured ideas of going to the ballet that evening to see an interesting program of one-acters with music by Scriabin, Bartok and Prokofiev.

There seemed ample time for all this, but in reality we were still there some three and a half hours later engaged most exasperatingly in watching Petrosian miss chance after chance of finishing off the game. Flohr never saw his guests nor I the ballet and Petrosian's play seemed more incomprehensible than ever. Later, however, we learnt that Petrosian had eaten something that disagreed with him and was not feeling well during all the period of resumption of play. In fact, the next game had to be postponed because of this - he was suffering from a surfeit of points was the press-room comment - and this was the first known case in the history of world championship chess when a player fell sick after winning two games in succession.>

This made me curious to recheck 53. g4+ which Calli criticized (and I and a few other kibitzers tried to analyze) above.

The site's Stockfish shows that 53. g4+ is +0.99 while 53. Rd5+ is +2.75, which is a major difference (drop from "clearly winning" to "big edge"), and it's hard to conclude Stockfish thinks that decision is "okay."

I'm perfectly willing to concede that this ending was not played as well as it should have been, and maybe it really doesn't deserve to be in Clarke's book, depending on how you feel about the quality of the first session. But the idea that Botvinnik was dissing an opponent he was losing badly to at the time by playing out an ending he would have resigned against somebody else seems more like Golombek's wishful thinking than Botvinnik's actual view.

Golombek's comments indicate that he thought Botvinnik should have won the match. That's fine to feel that way, but it's a bit iffy for a match judge to say, not years later, but in coverage of the match.

We've actually got computer annotations here and those also flag 35. Rc4, 53. g4+, and 55. Rxc7 with question marks, besides 52. Nxh7 from your list.

But I have Clarke's book, and as a reader I remember being annoyed that one win was missing. Same with Alekhine's book. Even if the missing win wasn't that great, as a reader you still want to see it.