Answers.Body: <p>Chess engines prefer to checkmate you as soon as they can, and if they can checkmate you in 10 moves, they look if they can also checkmate you in 9 moves. That's also why chess.com thinks rook promotion is better, because it saw a sooner mate. But if you see a mate in 3 and don't see the mate in 1, just play the mate in 3</p>
  
Answers.ContentLicense: CC BY-SA 4.0
Answers.CreationDate: 2021-03-30T15:58:54.203Z
Answers.LastActivityDate: 2021-03-30T15:58:54.203Z
Answers.UserDisplayName: Irsu85
Answers.Body: <p>There's no reason why the rook promotion is better. Don't listen to engines in positions where there's such a big imbalance</p>
  
Answers.ContentLicense: CC BY-SA 4.0
Answers.CreationDate: 2021-03-29T11:54:41.913Z
Answers.LastActivityDate: 2021-03-29T11:54:41.913Z
Answers.UserDisplayName: David
Body: <p>I was analyzing a game on chess.com and it showed me that, in the below scenario, it is better to promote to a rook instead of promoting to a queen. It also shows that it has a mate in 6 with the queen, but it also a mate in 4.</p>
  <p>I am not sure why chess.com thinks it is mate in 6 and why the rook move is better. I am only ~1200 so I could be missing something obvious. Do you have any ideas?</p>
  <p>The game can be seen below, or <a href="https://www.chess.com/analysis/game/live/10752384105" rel="nofollow noreferrer">here</a> on chess.com.</p>
  <p><a href="https://i.sstatic.net/leEkQ.png" rel="nofollow noreferrer"><img src="https://i.sstatic.net/leEkQ.png" alt="Chess.com analysis" /></a></p>
  <pre><code>[fen &quot;2k3r1/ppp4P/3rp1Q1/8/3P4/4q3/PPP5/1K1R2R1 w - - 0 1&quot;]
  1. d4 d5 Bf4 Nc6 Nf3 Bf5 e3 Nf6 Bd3 Bg6 Nc3 e6 Ne5 Be7 h4 Nxe5 Bxe5 Qd7 g4 Bxd3 Qxd3 O-O-O g5 Ne4 Nxe4 dxe4 Qxe4 Bd6 Bxg7 Rhg8 Bf6 Be7 Bxe7 Qxe7 O-O-O Qd6 Qxh7 Qa6 Kb1 Qd6 Qxf7 Rgf8 Qh5 Rxf2 g6 Rff8 g7 Rg8 Rhg1 Rd7 Qh8 Rdd8 Qh7 Qd5 h5 Qf3 h6 Qxe3 Qg6 Rd6 h7 Rgd8 g8=Q Rxg8 hxg8=Q+ Rd8 Qxd8+ Kxd8 Qh7 Qc1+ Rxc1 c5 Rg8#
  </code></pre>
  
Comments.ContentLicense: CC BY-SA 4.0
Comments.CreationDate: 2021-03-29T11:33:51.813Z
Comments.Text: Seems like the analysis engine prefers to throw away less material, but promoting to a queen and exchanging it for the rook on d8 leads to the same mate.
Comments.UserDisplayName: Maciej Stachowski
Comments.ContentLicense: CC BY-SA 4.0
Comments.CreationDate: 2021-03-29T11:45:03.760Z
Comments.Text: Stockfish engine depth issues. More time, higher depth it will see better.
Comments.UserDisplayName: SmallChess
Comments.ContentLicense: CC BY-SA 4.0
Comments.CreationDate: 2021-03-29T12:55:49.080Z
Comments.Text: @MaciejStachowski The engine line 34. Q6e8 also attempts to sacrifice a queen for the rook and if it had the clear choice between #6 and #4, the engine would pick the #4 no matter the material. But it just doesn't see the #4 yet - likely unfortunate pruning at work (which will be fixed by going to higher depths as SmallChess notes).
Comments.UserDisplayName: Annatar
Tags: <analysis><checkmate><pawn-promotion><chess.com>
Title: In chess.com analysis, why is a rook promotion better than a queen promotion?
ThreadText: # In chess.com analysis, why is a rook promotion better than a queen promotion?
  
  (Asked by: username_0 on 2021-03-29)
  
  I was analyzing a game on chess.com and it showed me that, in the below scenario, it is better to promote to a rook instead of promoting to a queen. It also shows that it has a mate in 6 with the queen, but it also a mate in 4.
  
  I am not sure why chess.com thinks it is mate in 6 and why the rook move is better. I am only ~1200 so I could be missing something obvious. Do you have any ideas?
  
  The game can be seen below, or [here](https://www.chess.com/analysis/game/live/10752384105) on chess.com.
  
  [![Chess.com analysis](https://i.sstatic.net/leEkQ.png)](https://i.sstatic.net/leEkQ.png)
  
  ```
  [fen "2k3r1/ppp4P/3rp1Q1/8/3P4/4q3/PPP5/1K1R2R1 w - - 0 1"]
  1. d4 d5 Bf4 Nc6 Nf3 Bf5 e3 Nf6 Bd3 Bg6 Nc3 e6 Ne5 Be7 h4 Nxe5 Bxe5 Qd7 g4 Bxd3 Qxd3 O-O-O g5 Ne4 Nxe4 dxe4 Qxe4 Bd6 Bxg7 Rhg8 Bf6 Be7 Bxe7 Qxe7 O-O-O Qd6 Qxh7 Qa6 Kb1 Qd6 Qxf7 Rgf8 Qh5 Rxf2 g6 Rff8 g7 Rg8 Rhg1 Rd7 Qh8 Rdd8 Qh7 Qd5 h5 Qf3 h6 Qxe3 Qg6 Rd6 h7 Rgd8 g8=Q Rxg8 hxg8=Q+ Rd8 Qxd8+ Kxd8 Qh7 Qc1+ Rxc1 c5 Rg8#
  
  ```
  
  **Tags:** analysis, checkmate, pawn-promotion, chess.com
  
  > **Comments:**
  > **username_1**: Seems like the analysis engine prefers to throw away less material, but promoting to a queen and exchanging it for the rook on d8 leads to the same mate.  
  > **username_2**: Stockfish engine depth issues. More time, higher depth it will see better.  
  > **username_3**: @username_1 The engine line 34. Q6e8 also attempts to sacrifice a queen for the rook and if it had the clear choice between #6 and #4, the engine would pick the #4 no matter the material. But it just doesn't see the #4 yet - likely unfortunate pruning at work (which will be fixed by going to higher depths as username_2 notes).  
  
  ---
  
  ## 2 answers
  
  ### Answer by username_5 on 2021-03-29. Score: 8 | Accepted answer
  
  There's no reason why the rook promotion is better. Don't listen to engines in positions where there's such a big imbalance
  
  
  ---
  
  ### Answer by username_4 on 2021-03-30. Score: 2
  
  Chess engines prefer to checkmate you as soon as they can, and if they can checkmate you in 10 moves, they look if they can also checkmate you in 9 moves. That's also why chess.com thinks rook promotion is better, because it saw a sooner mate. But if you see a mate in 3 and don't see the mate in 1, just play the mate in 3
  
  
  ---
  
  