Answers.Body: <p>I'm not sure exactly how you'd be satisfied with an answer here, but yes this famous position is zugzwang. First of all the f1 knight cannot move without allowing Qxe3. The f2 knight cannot move without allowing Ng4! Rxe2 fxe2, winning. The rook cannot move without allowing Ne4! which cannot be taken due to Qg2#. And the king cannot move without allowing Qxf1. So really, the only moves left to consider are pawn moves.</p>
  <pre><code>[FEN &quot;8/2p3pk/5n1p/5P2/3P1P1P/4Pp2/4qN1R/5NK1 w - - 1 41&quot;]
  
  1. e4 {is the only remaining try} (1. d5 Nxd5 {not played in the game - Kg8 was, just taunting Bogoljubov - but this is simplest}) (1. h5 Kh8! {Just to show the zugzwang, this move never accomplishes anything} 2. Rh4? Ne4! {which cannot be taken due to Qg2#} 3. Rh2 Nd2 4. Nxd2 Qxd2 {and black has broken through. Qxe3 or Qxf4 are unstoppable.}) Kh8 {not completely forced, but just to show that it's Zugzwang, we will consider this move.} 2. e5 (2. d5 Kh7! {once again showing the Zug} 3. h5 Kh8 4. e5 Nd5 {winning a pawn and the f4 pawn next}) Nd5 {and Nxf4 is unstoppable} 3. Ng4 Qe4 {does not change the nature of the position, white is losing all the pawns next.}
  </code></pre>
  <p>Once you exhaust all the possible pawn moves, it's easy to see that white has nothing to do.</p>
  <p>Stockfish 14 says -5.1 at depth 28, with the top moves being all the three pawn moves we considered. If you pass the move, then the threat is Kg8 haha once again passing the move onto white with an evaluation of -5.1 as well.</p>
  
Answers.ContentLicense: CC BY-SA 4.0
Answers.CreationDate: 2022-09-27T19:13:49.910Z
Answers.Text: If anyone wants to explore the whole game further: https://lichess.org/Z3a34Poh
Answers.UserDisplayName: NoseKnowsAll
Answers.ContentLicense: CC BY-SA 4.0
Answers.CreationDate: 2022-09-27T19:13:24.760Z
Answers.LastActivityDate: 2022-09-27T19:22:02.730Z
Answers.LastEditDate: 2022-09-27T19:22:02.730Z
Answers.UserDisplayName: NoseKnowsAll
Body: <p><a href="https://de.wikipedia.org/wiki/Bogoljubow_%E2%80%93_Aljechin,_Hastings_1922" rel="nofollow noreferrer">The German wiki</a> has a whole page devoted only to this game, so I won't paste it here. Even as a very small kid with a rating of 1500 or so, I always wondered: is it really Zugzwang after 40...Qe2? Nonsense!, I thought. We can simply play h5 and then Rh4! puts a stop to the Ng4 idea. Doesn't this show that the position isn't Zugzwang?</p>
  <p>Note that this doesn't claim White is not busted (he is), but merely that it isn't Zugzwang. Indeed, the best move of Black after h5 is given by the engine as Nd5, i.e. action. Let's be formal but lenient (if White is losing anyway, it can't be Zugzwang, strictly speaking game-theory-wise): we define White to be in Zugzwang if &quot;pass&quot; is the best centipawn move in the position. Rh4 makes Nd5 worse, since Ng4 is no longer possible, so this could be so. Obviously, Lichess Stockfish can't pass since that would be an illegal move, but I can enter the FEN with the &quot;wrong&quot; player to move, though. With a shallow analysis, I get -3.7 with WTM and -4.2 with BTM on standard depth 22. This is still not convincing: Black plays Kg8 and improves his king position for the big Qe2 exchange.</p>
  <p>Can somebody (best with an engine allowing pass moves) analyze this deeper? I'd accept &quot;Zugzwang&quot; if, see above, White's centipawn value is least bad after a pass move.</p>
  
Comments.ContentLicense: CC BY-SA 4.0
Comments.CreationDate: 2022-09-27T18:52:58.120Z
Comments.Text: FYI Lichess stockfish can pass. Click the bullseye looking button next to the toggle for the engine (or press x) to show the threat of the position with a pass.
Comments.UserDisplayName: NoseKnowsAll
Comments.ContentLicense: CC BY-SA 4.0
Comments.CreationDate: 2022-09-28T07:22:55.873Z
Comments.Text: Oh, THX for the info. I didn't hit all buttons yet, my computer is 20 years old and might explode :-)
Comments.UserDisplayName: Hauke Reddmann
Comments.ContentLicense: CC BY-SA 4.0
Comments.CreationDate: 2024-07-25T11:11:33.410Z
Comments.Text: White is probably losing even with pass moves.
Comments.UserDisplayName: Lucenaposition
Tags: <analysis><history>
Title: Bogoljubow – Aljechin, Hastings 1922 - Zugzwang?
ThreadText: # Bogoljubow – Aljechin, Hastings 1922 - Zugzwang?
  
  (Asked by: username_0 on 2022-09-27)
  
  [The German wiki](https://de.wikipedia.org/wiki/Bogoljubow_%E2%80%93_Aljechin,_Hastings_1922) has a whole page devoted only to this game, so I won't paste it here. Even as a very small kid with a rating of 1500 or so, I always wondered: is it really Zugzwang after 40...Qe2? Nonsense!, I thought. We can simply play h5 and then Rh4! puts a stop to the Ng4 idea. Doesn't this show that the position isn't Zugzwang?
  
  Note that this doesn't claim White is not busted (he is), but merely that it isn't Zugzwang. Indeed, the best move of Black after h5 is given by the engine as Nd5, i.e. action. Let's be formal but lenient (if White is losing anyway, it can't be Zugzwang, strictly speaking game-theory-wise): we define White to be in Zugzwang if "pass" is the best centipawn move in the position. Rh4 makes Nd5 worse, since Ng4 is no longer possible, so this could be so. Obviously, Lichess Stockfish can't pass since that would be an illegal move, but I can enter the FEN with the "wrong" player to move, though. With a shallow analysis, I get -3.7 with WTM and -4.2 with BTM on standard depth 22. This is still not convincing: Black plays Kg8 and improves his king position for the big Qe2 exchange.
  
  Can somebody (best with an engine allowing pass moves) analyze this deeper? I'd accept "Zugzwang" if, see above, White's centipawn value is least bad after a pass move.
  
  **Tags:** analysis, history
  
  > **Comments:**
  > **username_1**: FYI Lichess stockfish can pass. Click the bullseye looking button next to the toggle for the engine (or press x) to show the threat of the position with a pass.  
  > **username_0**: Oh, THX for the info. I didn't hit all buttons yet, my computer is 20 years old and might explode :-)  
  > **username_2**: White is probably losing even with pass moves.  
  
  ---
  
  ## 1 answers
  
  ### Answer by username_1 on 2022-09-27. Score: 2
  
  I'm not sure exactly how you'd be satisfied with an answer here, but yes this famous position is zugzwang. First of all the f1 knight cannot move without allowing Qxe3. The f2 knight cannot move without allowing Ng4! Rxe2 fxe2, winning. The rook cannot move without allowing Ne4! which cannot be taken due to Qg2#. And the king cannot move without allowing Qxf1. So really, the only moves left to consider are pawn moves.
  
  ```
  [FEN "8/2p3pk/5n1p/5P2/3P1P1P/4Pp2/4qN1R/5NK1 w - - 1 41"]
  
  1. e4 {is the only remaining try} (1. d5 Nxd5 {not played in the game - Kg8 was, just taunting Bogoljubov - but this is simplest}) (1. h5 Kh8! {Just to show the zugzwang, this move never accomplishes anything} 2. Rh4? Ne4! {which cannot be taken due to Qg2#} 3. Rh2 Nd2 4. Nxd2 Qxd2 {and black has broken through. Qxe3 or Qxf4 are unstoppable.}) Kh8 {not completely forced, but just to show that it's Zugzwang, we will consider this move.} 2. e5 (2. d5 Kh7! {once again showing the Zug} 3. h5 Kh8 4. e5 Nd5 {winning a pawn and the f4 pawn next}) Nd5 {and Nxf4 is unstoppable} 3. Ng4 Qe4 {does not change the nature of the position, white is losing all the pawns next.}
  
  ```
  
  Once you exhaust all the possible pawn moves, it's easy to see that white has nothing to do.
  
  Stockfish 14 says -5.1 at depth 28, with the top moves being all the three pawn moves we considered. If you pass the move, then the threat is Kg8 haha once again passing the move onto white with an evaluation of -5.1 as well.
  
  > **Comments:**
  > **username_1**: If anyone wants to explore the whole game further: https://lichess.org/Z3a34Poh  
  
  ---
  
  