In the game Euwe-Averbakh (Zurich Candidates, 1953), the following position was reached after 25...Ne7xf5.
The article "Note by Bronstein on Euwe-Averbakh (Zurich, 1953)" (https://www.redhotpawn.com/forum/only-chess/note-by-bronstein-on-euwe-averbakh-zurich-1953.191843) concluded that after 26. Re5 (recommended by Bronstein) 26...Qg6, one benefit of 27. Qxg6 (in contrast to advancing the h- or f-pawn to defend the queen) is that 27...hxg6 might make it harder for Black to win a single minor piece ending. (See next chess movie for this sequence.)
This PGN could not be parsed.
- move 1 could not be played: Invalid PGN : Error converting move Re5
[fen "r5nk/5rpp/1q6/3p1nQN/p1pP4/PpP2P2/1B2R1PP/R5K1 w - - - -"]
26. Re5 Qg6 27. Qxg6 hxg6
26. Re5 Qg6 27. Qxg6 hxg6
The present article continues from 27...hxg6.
White's knight could retreat to g3 or f4. (28. g4, attacking Black's knight, would be refuted by 28...Nh4, threatening 29...Nxf3+ and leaving White's knight en pris.) From the f4-square, the knight would be attacking two pawns. (The position after 28. Nf4 is shown in the next diagram.)
Black can't hold both pawns, but he can counter with 28...Nxd4, discovering on White's knight. (See next diagram.)
White would have a slew of possible captures:
A) 29. cxd4 Rxf4 30. Rxd5 would maintain material equality, at the cost of giving Black a passed c-pawn to go with the passed b-pawn.
B) 29. Nxg6+ Kh7, and now
B1) 30. cxd4 Kxg6 31. Rxd5 gains White a pawn but again leaves Black with a connected duo of passed pawns.
B2) 30. Rxd5 might unfold as depicted in the next chess movie (which starts with 29. Nxg6+).
This PGN could not be parsed.
- move 1 could not be played: Invalid PGN : Error converting move Nxg6
[fen "r5nk/5rp1/6p1/3pR3/p1pn1N2/PpP2P2/1B4PP/R5K1 w - - - -"]
29. Nxg6+ Kh7 30. Rxd5 {Now each side has a knight attacked.} Nc2 {Now White has two pieces attacked, but...} 31. Ne5 {Counterattacking against Black's rook.} Rf5 32. Rc1 {The otherwise desirable 32. Rad1 would walk into the fork 32...Ne3.} Re8 33. f4 {The only way to defend the knight.} Rxf4 34. Nf3 {Black was threatening to pin the poor steed again.} Nf6 {Black's piece activity has become alarming.}
29. Nxg6+ Kh7 30. Rxd5 {Now each side has a knight attacked.} Nc2 {Now White has two pieces attacked, but...} 31. Ne5 {Counterattacking against Black's rook.} Rf5 32. Rc1 {The otherwise desirable 32. Rad1 would walk into the fork 32...Ne3.} Re8 33. f4 {The only way to defend the knight.} Rxf4 34. Nf3 {Black was threatening to pin the poor steed again.} Nf6 {Black's piece activity has become alarming.}
C) 29. Rxd5 would transpose to line B2 after 29...Nc2 30. Nxg6+ Kh7.
D) 29. Nxd5 would eliminate the protector of Black's c-pawn, while threatening 30. Nb6, forking a8-rook and c-pawn. The necessity of Black's knight's escaping with tempo compels 29...Nc2, from which the knight has practically no mobility. But at least the knight will keep a White rook off e1 and pressure a3. (See next diagram.)
Where should the attacked rook go? One possibility is 30. Rd1, which is examined in the next chess movie.)
This PGN could not be parsed.
- move 1 could not be played: Invalid PGN : Error converting move Rd1
[fen "r5nk/5rp1/6p1/3NR3/p1p5/PpP2P2/1Bn3PP/R5K1 w - - - -"]
30. Rd1 {A near self-pin, which Black quickly exploits.} Rd8 {Threatening to double rooks, with ...Ne7 in reserve.} 31. Ne3 {The only move.} Rxd1+ 32. Nxd1 Rd7 {Not only attacking the knight but contemplating invasion at d2.} 33. Nf2 {Protecting d1 and d3, and prepared to answer 33...Rd2 by 34. Bc1.} Nf6 {Preparing several unpleasant mini-tours such as Nd5-f4-d3 or Nd5-e3-d1.}
30. Rd1 {A near self-pin, which Black quickly exploits.} Rd8 {Threatening to double rooks, with ...Ne7 in reserve.} 31. Ne3 {The only move.} Rxd1+ 32. Nxd1 Rd7 {Not only attacking the knight but contemplating invasion at d2.} 33. Nf2 {Protecting d1 and d3, and prepared to answer 33...Rd2 by 34. Bc1.} Nf6 {Preparing several unpleasant mini-tours such as Nd5-f4-d3 or Nd5-e3-d1.}
So, after 29...Nc2, where should the rook go instead? 30. Rc1 would seem to bite on mahogany ( not quite "granite" ), but the point is revealed in the next chess movie.
This PGN could not be parsed.
- move 1 could not be played: Invalid PGN : Error converting move Rc1
[fen "r5nk/5rp1/6p1/3NR3/p1p5/PpP2P2/1Bn3PP/R5K1 w - - - -"]
30. Rc1 Ra6 {To prevent the forking 31. Nb6.} 31. Nb4 {The point of 30. Rc1: Black's knight is now being attacked for a second time.} 31...Nxb4 32. cxb4 {White's c1-rook now looks well-placed.} 32...Rc6 33. b5 Rc8 34. Re4 {Black's queenside pawns are now in jeopardy, as White's last also threatens to win a piece by 35. Rh4+ Nh6 36. Rxh6+.}
30. Rc1 Ra6 {To prevent the forking 31. Nb6.} 31. Nb4 {The point of 30. Rc1: Black's knight is now being attacked for a second time.} 31...Nxb4 32. cxb4 {White's c1-rook now looks well-placed.} 32...Rc6 33. b5 Rc8 34. Re4 {Black's queenside pawns are now in jeopardy, as White's last also threatens to win a piece by 35. Rh4+ Nh6 36. Rxh6+.}
Another try, 30...Ra5, appears in the next chess movie.
This PGN could not be parsed.
- move 1 could not be played: Invalid PGN : Error converting move Rc1
[fen "r5nk/5rp1/6p1/3NR3/p1p5/PpP2P2/1Bn3PP/R5K1 w - - - -"]
30. Rc1 Ra5 {This seems to pin the knight.} 31. Ne7 {But, another fork looms.} 31...Rxe5 32. Nxg6+ Kh7 33. Nxe5 {If Black now plays 33...Rf4 or 33...Rc7, 34. Kf2 prepares Rd1 by first preventing ...Ne3.}
30. Rc1 Ra5 {This seems to pin the knight.} 31. Ne7 {But, another fork looms.} 31...Rxe5 32. Nxg6+ Kh7 33. Nxe5 {If Black now plays 33...Rf4 or 33...Rc7, 34. Kf2 prepares Rd1 by first preventing ...Ne3.}
30...Rd8 surrenders the pawn in the hope of invading at d2, but this doesn't seem to work for Black either, as shown in the next chess movie.
This PGN could not be parsed.
- move 1 could not be played: Invalid PGN : Error converting move Rc1
[fen "r5nk/5rp1/6p1/3NR3/p1p5/PpP2P2/1Bn3PP/R5K1 w - - - -"]
30. Rc1 Rd8 31. Nb6 Re7 32. Nxc4 Rxe5 33. Nxe5 Rd2 34. Nc4 Re2 35. Kf1 {Forcing the rook to quit the rank.}
30. Rc1 Rd8 31. Nb6 Re7 32. Nxc4 Rxe5 33. Nxe5 Rd2 34. Nc4 Re2 35. Kf1 {Forcing the rook to quit the rank.}
Conclusion: The position resulting from 26...Qg6 27. Qxg6 hxg6 seems better for White. Therefore, it seems that Bronstein was correct that 26. Re5 would have made it more difficult for Black to bring about a favorable ending.
(A list of the threads I've initiated at this forum is available at http://www.davidlevinchess.com/chess/RHP_my_threads.htm .)