<4.d4...> After the round, Najdorf and I sit in his room once again. Miguel smiles because he did not let his opponent to play Ben-Oni. And because now, during intermission, he stands to win.

<6.e3...> "6.e4 is also good," says Najdorf, "but I always like it when there is a lot of pieces on the board. Most of my games I won in the middle-game."

<10...Nxc3> Najdorf was surprised by the last move by Tal. "I expected Nf6," he says and continues to show me his game.

<16...Na5> Of course, 16...Bxh4 was not feasible for 17.Nxh4 Qxh4 18.Bg5 Qg4 19.Re4 Qf5 20.Rh4... with a devastating attack of White.

<17.Ng5...> After 17.Ne5 the pawn h4 could already be taken.

<19...Nc4> "What was I supposed to do?" asks Najdorf. "The 20.Qf4 was most attractive. Black can not play 20...e5 21.Qg3 exd4, because of 22.hxg6 hxg6 23.Ne6! and White wins. Nor he can play 20...Nb2 for 21.hxg6 with 22.Qh4! I though a whole hour here, but did not know what to play after the correct 20...h6!"

<23.f3...> Thus far, both players are playing flawlessly. White could not play the tempting 23.Ne4 f5 24.Qh6 for 24...Rc7!

<24.Qg3!...> For Najdorf, this must have been the hardest move in the game. The exchange 25.Qxf5 gxf5 26.Nd6 Rc7 27.c4 Rd8 would have probably been more advantageous for Black. By playing the last move, White actually sacrifices a pawn for an attack along the f-file.

<29.Ref3...> This is the core of the whole thing. Black now has problems protecting the black squares of his king-side.

<30.Qf4...> Outlines of the threat 31.Qf6+ with the following Rf3-f4-h4-h8 are suddenly on the board.

<31...Rxf3?> This in fact is the first and last Black error. After the correct 31...Qg5! 32.Rxc3 Rxc3 33.Qb8+ Kg7 34.Qxa7 Qe3+ 35.Kh1 Qh6+ 36.Kg1 Qe3+ the game would have ended a draw.

<32.Qd8+...> Important in-between move. I have to prize the move; Najdorf is watching if I am impressed. White takes under control the square h4.

<34...Rc3> Tal must have pinned his hopes upon this moves, but in vain.

<40...Kh5> Here, the game is adjourned. Najdorf knows that victory can no longer escape from his grasp. Deliberately and with epicurean care he writes the winning moves on a piece of paper. So that he does not forget? Rather that he can delight in the whole thing.

<44.Rf1!...> The winning move!

I wondered why Tal didn't play 29...Rxf3. After all, he's a pawn up and on the defensive, and in those situations it's generally desirable to reduce the number of pieces on the board since it makes the attack more difficult and increases the power of the extra pawn.

Stockfish 10 at d=43 evaluates the position as dead even, [0.00], after either 29...f5, 29...Rxf3, 29...Kg8, or 29...f6. Black doesn't seem to have a problem on the dark squares. But after 29...R8c7 as played by Tal Stockfish at d=43 evaluates the position at as decisively winning for White, [+8.20], after Najdorf's 30.Qf4.

My take here is that perhaps the most obvious defensive move in the position <Rc8-c7> is in fact weak. For instance, after the sequence <29...Rxc3 30.Qxf3 Rc7? 31.Qf6+...> Black is lost. (More or less, because of the general weakness of black K-side squares.)