Answers.Body: <blockquote>
  <p>Why does a Queen promotion not win him the game?</p>
  </blockquote>
  <p>Because black can play the kamikaze Qg2+ forcing stalemate after Kxg2.</p>
  <p>Here is the critical position in the game where Hjartarson could have forced through the pawn to promote via the queen sacrifice Qf7+ but needs to promote to a bishop. Hjartarson instead played e7 leading to a draw. Presumably he calculated the queen sacrifice and saw that promoting to a queen led to stalemate but didn't calculate the underpromotion.</p>
  <pre><code>[title &quot;Hjartarson vs Andersen Reykjavik Open 2022&quot;]
  [fen &quot;4r1k1/3R2p1/2q1P2p/5QnP/5N2/6P1/5P2/6K1 w - - 0 1&quot;]
  
  1. e7 (1. Qf7+ Nxf7 2. exf7+ Kh7 3. fxe8=B! (3. fxe8=Q? Qg2+ 4. Kxg2=))
  </code></pre>
  
Answers.ContentLicense: CC BY-SA 4.0
Answers.CreationDate: 2022-09-12T15:16:22.450Z
Answers.LastActivityDate: 2022-09-12T15:16:22.450Z
Answers.UserDisplayName: Brian Towers
Body: <p><a href="https://www.chess.com/news/view/praggnanandhaa-wins-2022-reykjavik-open" rel="noreferrer">Chess.com - Praggnanandhaa wins 2022 Reykjavik Open</a>:</p>
  <blockquote>
  <p>he missed a unique underpromotion to a bishop as the only move to win the position</p>
  </blockquote>
  <p>Why does a Queen promotion not win him the game?</p>
  
Tags: <analysis><pawn-promotion>
Title: Why underpromote? Hjartarson vs Andersen
ThreadText: # Why underpromote? Hjartarson vs Andersen
  
  (Asked by: username_0 on 2022-09-12)
  
  [Chess.com - Praggnanandhaa wins 2022 Reykjavik Open](https://www.chess.com/news/view/praggnanandhaa-wins-2022-reykjavik-open):
  
  > he missed a unique underpromotion to a bishop as the only move to win the position
  
  Why does a Queen promotion not win him the game?
  
  **Tags:** analysis, pawn-promotion
  
  
  ---
  
  ## 1 answers
  
  ### Answer by username_1 on 2022-09-12. Score: 36 | Accepted answer
  
  > Why does a Queen promotion not win him the game?
  
  Because black can play the kamikaze Qg2+ forcing stalemate after Kxg2.
  
  Here is the critical position in the game where Hjartarson could have forced through the pawn to promote via the queen sacrifice Qf7+ but needs to promote to a bishop. Hjartarson instead played e7 leading to a draw. Presumably he calculated the queen sacrifice and saw that promoting to a queen led to stalemate but didn't calculate the underpromotion.
  
  ```
  [title "Hjartarson vs Andersen Reykjavik Open 2022"]
  [fen "4r1k1/3R2p1/2q1P2p/5QnP/5N2/6P1/5P2/6K1 w - - 0 1"]
  
  1. e7 (1. Qf7+ Nxf7 2. exf7+ Kh7 3. fxe8=B! (3. fxe8=Q? Qg2+ 4. Kxg2=))
  
  ```
  
  
  ---
  
  