Answers.Body: <p>Chess engines are made for regular chess playing not for solving unexpected chess problems that have no very little relevance to chess strength. In fact, an engine that is able to understand an endgame pattern like this would play weaker chess because some CPU cycles would have been wasted on counting the number of bishops on the same colour.</p>
  <p>There is no reason for Stockfish to incorporate an endgame knowledge like this. Stockfish could simply play until the fifty-move draw while showing &quot;-28.8&quot; evaluation scores. There's no harm - playing more moves is a draw, stopping immediately is also a draw.</p>
  
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Answers.UserDisplayName: SmallChess
Answers.Body: <p>Computer programs are great at performing the specific tasks they've been designed for and useless for anything else. Chess engines are no different. It's just not worth it to design an engine so that it can manage these sort of edge cases.</p>
  <p>As far as the engine can calculate, Black has a huge material advatange and after the sequences of moves it can see, if keeps that advantage. In the overwhelming majority of chess positions, the correct way to interpret this fact is that Black has a much better position.</p>
  <p>Given enough time and computing power, Stockfish would realize there's no way to deliver checkmate within the next 50 moves, but keep in mind that computers don't have our human intuitions. All they can do is perform a search on the move tree and apply an evaluation function to each of the relevant positions. It can't think in terms of &quot;all my bishops are on light squares, so 7 bishops are effectively the same as just 1&quot;.</p>
  <p>As for why -28 and not -21 or any other number, well, from a certain point on all evaluations are pretty much the same. If you see -7, -15 or -60 that just means &quot;I think Black is winning but I can't find a specific line that ends in checkmate&quot;. Evaluation functions are designed to find nouance in positions that are close to equality, but not so much when we have unbalances as big as this one. Either way a bishop being worth 3 points is just a heuristic for human beginners, not a rule engines would take seriously.</p>
  
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Answers.Text: Thanks for the answer! To me, there is a difference between -7 and -60 positions: If my score is -7, I know if my opponent blunders his/her queen, I may equalise the position; if my score is -60, my olny hope is probably stalemate.
Answers.UserDisplayName: Zuriel
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Answers.Text: @Zuriel engines don't have that concept of "difficulty" though. It's only about how far into their winning sequence they can calculate. A position may be +15 but require you to find a very specific hard to see move while naother one could be +5 with almost any move. So yeah I'd say there's a tendency for positions with a bigger evaluation number to be more "hopeless", but it doesn't always work.
Answers.UserDisplayName: David
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Answers.UserDisplayName: David
Body: <pre><code>[FEN &quot;5K2/8/5k2/5b2/6b1/5b1b/4b1b1/7b w - - 0 1&quot;]
  </code></pre>
  <p>This game is an immediate draw by insufficient material (<strong>Doesn't Stockfish know this?</strong>). I am wondering what the reason behind the score &quot;-28.8&quot; is. Even -21 makes more sense to me than -28.8 since each bishop is worth 3 points.</p>
  
Comments.ContentLicense: CC BY-SA 4.0
Comments.CreationDate: 2022-12-16T15:44:04.313Z
Comments.Text: As I understand things, engine evaluations do not follow the 1 point = 1 pawn scale anymore (at least for Stockfish).
Comments.UserDisplayName: SecretAgentMan
Comments.ContentLicense: CC BY-SA 4.0
Comments.CreationDate: 2022-12-16T16:02:31.877Z
Comments.Text: @SecretAgentMan, then 1 pawn = how many points?
Comments.UserDisplayName: Zuriel
Comments.ContentLicense: CC BY-SA 4.0
Comments.CreationDate: 2022-12-18T18:36:42.703Z
Comments.Text: It is only an immediate draw to you because you have some specific endgame knowledge to infer from.
Comments.UserDisplayName: Thorbjørn Ravn Andersen
Comments.ContentLicense: CC BY-SA 4.0
Comments.CreationDate: 2022-12-19T12:10:42.103Z
Comments.Text: @ThorbjørnRavnAndersen, but this endgame knowledge is clear to most human players.
Comments.UserDisplayName: Zuriel
Comments.ContentLicense: CC BY-SA 4.0
Comments.CreationDate: 2022-12-19T12:19:19.090Z
Comments.Text: @Zuriel most human players have been taught this.  Nobody taught stockfish.
Comments.UserDisplayName: Thorbjørn Ravn Andersen
Comments.ContentLicense: CC BY-SA 4.0
Comments.CreationDate: 2022-12-19T12:40:22.957Z
Comments.Text: @ThorbjørnRavnAndersen, even if a player has never been taught about this endgame, if his/her rating is 2000+, I am sure that this player can easily figure it out given some time.
Comments.UserDisplayName: Zuriel
Comments.ContentLicense: CC BY-SA 4.0
Comments.CreationDate: 2022-12-19T12:50:02.693Z
Comments.Text: @Zuriel Probably yes.  I agree this is for inexperienced players, and they may actually take a while to see it.   Such a situation would most likely be presented to them by a more experienced player or a teacher, for learning purposes.
Comments.UserDisplayName: Thorbjørn Ravn Andersen
Comments.ContentLicense: CC BY-SA 4.0
Comments.CreationDate: 2022-12-23T09:54:53.830Z
Comments.Text: @Zuriel the objective of chess is to deliver checkmate, so evaluation functions exist to reflect how likely a player is to achieve that goal. There's no fixed value for a pawn because a strong pawn on the center is not worth the same as a backward pawn on a semi-open file. Some pawns even have "negative value" as they're blocking their own pieces and it'd be benefitial to sacrifice them.
Comments.UserDisplayName: David
Tags: <engines><stockfish><draw><bishops><bishop-endgame>
Title: Why does stockfish give "-28.8" as the evaluation number for this position?
ThreadText: # Why does stockfish give "-28.8" as the evaluation number for this position?
  
  (Asked by: username_0 on 2022-12-16)
  
  [FEN "5K2/8/5k2/5b2/6b1/5b1b/4b1b1/7b w - - 0 1"]
  
  This game is an immediate draw by insufficient material (Doesn't Stockfish know this?). I am wondering what the reason behind the score "-28.8" is. Even -21 makes more sense to me than -28.8 since each bishop is worth 3 points.
  
  **Tags:** engines, stockfish, draw, bishops, bishop-endgame
  
  > **Comments:**
  > **username_1**: As I understand things, engine evaluations do not follow the 1 point = 1 pawn scale anymore (at least for Stockfish).  
  > **username_0**: @username_1, then 1 pawn = how many points?  
  > **username_2**: It is only an immediate draw to you because you have some specific endgame knowledge to infer from.  
  > **username_0**: @ThorbjørnRavnAndersen, but this endgame knowledge is clear to most human players.  
  > **username_2**: @username_0 most human players have been taught this.  Nobody taught stockfish.  
  > **username_0**: @ThorbjørnRavnAndersen, even if a player has never been taught about this endgame, if his/her rating is 2000+, I am sure that this player can easily figure it out given some time.  
  > **username_2**: @username_0 Probably yes.  I agree this is for inexperienced players, and they may actually take a while to see it.   Such a situation would most likely be presented to them by a more experienced player or a teacher, for learning purposes.  
  > **username_3**: @username_0 the objective of chess is to deliver checkmate, so evaluation functions exist to reflect how likely a player is to achieve that goal. There's no fixed value for a pawn because a strong pawn on the center is not worth the same as a backward pawn on a semi-open file. Some pawns even have "negative value" as they're blocking their own pieces and it'd be benefitial to sacrifice them.  
  
  ---
  
  ## 2 answers
  
  ### Answer by username_3 on 2022-12-16. Score: 11 | Accepted answer
  
  Computer programs are great at performing the specific tasks they've been designed for and useless for anything else. Chess engines are no different. It's just not worth it to design an engine so that it can manage these sort of edge cases.
  
  As far as the engine can calculate, Black has a huge material advatange and after the sequences of moves it can see, if keeps that advantage. In the overwhelming majority of chess positions, the correct way to interpret this fact is that Black has a much better position.
  
  Given enough time and computing power, Stockfish would realize there's no way to deliver checkmate within the next 50 moves, but keep in mind that computers don't have our human intuitions. All they can do is perform a search on the move tree and apply an evaluation function to each of the relevant positions. It can't think in terms of "all my bishops are on light squares, so 7 bishops are effectively the same as just 1".
  
  As for why -28 and not -21 or any other number, well, from a certain point on all evaluations are pretty much the same. If you see -7, -15 or -60 that just means "I think Black is winning but I can't find a specific line that ends in checkmate". Evaluation functions are designed to find nouance in positions that are close to equality, but not so much when we have unbalances as big as this one. Either way a bishop being worth 3 points is just a heuristic for human beginners, not a rule engines would take seriously.
  
  > **Comments:**
  > **username_0**: Thanks for the answer! To me, there is a difference between -7 and -60 positions: If my score is -7, I know if my opponent blunders his/her queen, I may equalise the position; if my score is -60, my olny hope is probably stalemate.  
  > **username_3**: @username_0 engines don't have that concept of "difficulty" though. It's only about how far into their winning sequence they can calculate. A position may be +15 but require you to find a very specific hard to see move while naother one could be +5 with almost any move. So yeah I'd say there's a tendency for positions with a bigger evaluation number to be more "hopeless", but it doesn't always work.  
  
  ---
  
  ### Answer by username_4 on 2022-12-17. Score: 4
  
  Chess engines are made for regular chess playing not for solving unexpected chess problems that have no very little relevance to chess strength. In fact, an engine that is able to understand an endgame pattern like this would play weaker chess because some CPU cycles would have been wasted on counting the number of bishops on the same colour.
  
  There is no reason for Stockfish to incorporate an endgame knowledge like this. Stockfish could simply play until the fifty-move draw while showing "-28.8" evaluation scores. There's no harm - playing more moves is a draw, stopping immediately is also a draw.
  
  
  ---
  
  