Answers.Body: <p>It would be easy to detect sacrifices- if the material count in the position suddenly drops, but the computer evaluation position doesn't drop a lot, and the material isn't restored within a short number of moves (to avoid simple exchanges being considered sacrifices), then it would be a sound sacrifice. This would miss out on a lot of unsound sacrifices or sacrifices that computers don't understand, however- there are many cases of this with fortresses etc. Detecting brilliant sacrifices would probably be even harder.</p>
  
Answers.ContentLicense: CC BY-SA 4.0
Answers.CreationDate: 2020-08-10T01:48:52.077Z
Answers.Text: So to clarify, you are saying that "sound" sacrifices can be guaranteed to be detected? Or are you saying that even some sacrifices deemed to be sound by the method you described can ultimately be proven to be unsound?
Answers.UserDisplayName: Wins94
Answers.ContentLicense: CC BY-SA 4.0
Answers.CreationDate: 2020-08-10T04:35:12.870Z
Answers.Text: Also, the method you describe needs material count, something that is not readily given by the PGN and evaluation score.
Answers.UserDisplayName: Wins94
Answers.ContentLicense: CC BY-SA 4.0
Answers.CreationDate: 2020-08-10T08:26:57.203Z
Answers.Text: Material count is easy to calculate given a PGN, right
Answers.UserDisplayName: justhalf
Answers.ContentLicense: CC BY-SA 4.0
Answers.CreationDate: 2020-08-10T16:21:19.460Z
Answers.Text: A well-placed pawn is worth more than a badly-placed bishop.  If one makes a move that nominally trades a pawn for a bishop, but does so in a way that the capturing pawn completely cuts an opponent's bishop out of the action, is that a "sacrifice"?
Answers.UserDisplayName: supercat
Answers.ContentLicense: CC BY-SA 4.0
Answers.CreationDate: 2020-08-10T18:28:15.703Z
Answers.Text: Note that these "difficult to detect" sacrifices indicate flaws in the engine - if you're able to find such a condition manually you would want to bring it up to the developers of the engine you're using!
Answers.UserDisplayName: corsiKa
Answers.ContentLicense: CC BY-SA 4.0
Answers.CreationDate: 2020-08-10T22:24:44.943Z
Answers.Text: Supercat, yes, even though it may not be a "brilliant" sacrifice, it is technically a sound sacrifice. But more interestingly, and I think this is what @pulsar512b meant, is that the engine (due to the inactivity of the bishop) might deem such sacrifice as sound yet it might in reality have been unsound strategically.
Answers.UserDisplayName: Wins94
Answers.ContentLicense: CC BY-SA 4.0
Answers.CreationDate: 2020-08-10T23:17:11.717Z
Answers.Text: @justhalf How can it be done? I want to program it using VBA in Excel. Is that easily done?
Answers.UserDisplayName: Wins94
Answers.ContentLicense: CC BY-SA 4.0
Answers.CreationDate: 2020-08-11T07:28:22.197Z
Answers.Text: A very simple method would be to search for the piece that last moved into the captured square (this will fail for en passant, but can be rectified with an additional conditional). Definitely doable in VBA. This will fail to account for the captures of rooks immediately after castling, but also can be rectified by replacing castling notation by rook moving to the corresponding square (king doesn't need to be tracked since they won't be captured)
Answers.UserDisplayName: justhalf
Answers.ContentLicense: CC BY-SA 4.0
Answers.CreationDate: 2020-08-11T11:29:45.107Z
Answers.Text: @justhalf Thank you! So do you recommend that after each move a position table (one that would have to change after each move) be looked up to see what piece was captured? Or should it be done with arrays?
Answers.UserDisplayName: Wins94
Answers.ContentLicense: CC BY-SA 4.0
Answers.CreationDate: 2020-08-11T11:45:11.367Z
Answers.Text: My first idea would be to split the first letter (with exceptions like castling and pawn moves) so you have the piece and the square it moves into, then you can do a lookup (array/map would work)
Answers.UserDisplayName: justhalf
Answers.ContentLicense: CC BY-SA 4.0
Answers.CreationDate: 2020-08-11T11:58:22.613Z
Answers.Text: @justhalf Thanks, I'll give it a try. I find it interesting that material information is not incorporated into evaluation tools as there is so much info that can be extracted about the player tendencies/skills from it. For example, it can reveal the player's sacrificing tendencies, how well they play depending on their material, and how much they prioritize position over material.
Answers.UserDisplayName: Wins94
Answers.ContentLicense: CC BY-SA 4.0
Answers.CreationDate: 2020-08-11T13:03:30.467Z
Answers.Text: I guess that's because people are more interested in how likely a position is to win, which is shown by the evaluation score instead of the material points.
Answers.UserDisplayName: justhalf
Answers.ContentLicense: CC BY-SA 4.0
Answers.CreationDate: 2020-08-11T15:09:44.637Z
Answers.Text: @justhalf I understand that the evaluation score is more important than the material score but I just think having both pieces of information in combination provides much greater insight into the player.
Answers.UserDisplayName: Wins94
Answers.ContentLicense: CC BY-SA 4.0
Answers.CreationDate: 2020-08-11T15:25:21.030Z
Answers.Text: @Wins9 almost all sound sacrifices would be caught- on occasion the engine may be wrong, however! It's probably fine, however.
Answers.UserDisplayName: pulsar512b
Answers.ContentLicense: CC BY-SA 4.0
Answers.CreationDate: 2020-08-09T21:34:33.210Z
Answers.LastActivityDate: 2020-08-09T21:34:33.210Z
Answers.UserDisplayName: pulsar512b
Body: <p>Is it possible to deduce brilliant sacrifices by analyzing a match's PGN along with the corresponding evaluation score after each move? If not, what other non-visual information would be needed to be able to deduce when a player made sacrifices to help his cause?</p>
  
Tags: <evaluation><sacrifice>
Title: Deducing brilliant sacrifices
ThreadText: # Deducing brilliant sacrifices
  
  (Asked by: username_0 on 2020-08-09)
  
  Is it possible to deduce brilliant sacrifices by analyzing a match's PGN along with the corresponding evaluation score after each move? If not, what other non-visual information would be needed to be able to deduce when a player made sacrifices to help his cause?
  
  **Tags:** evaluation, sacrifice
  
  
  ---
  
  ## 1 answers
  
  ### Answer by username_1 on 2020-08-09. Score: 8
  
  It would be easy to detect sacrifices- if the material count in the position suddenly drops, but the computer evaluation position doesn't drop a lot, and the material isn't restored within a short number of moves (to avoid simple exchanges being considered sacrifices), then it would be a sound sacrifice. This would miss out on a lot of unsound sacrifices or sacrifices that computers don't understand, however- there are many cases of this with fortresses etc. Detecting brilliant sacrifices would probably be even harder.
  
  > **Comments:**
  > **username_0**: So to clarify, you are saying that "sound" sacrifices can be guaranteed to be detected? Or are you saying that even some sacrifices deemed to be sound by the method you described can ultimately be proven to be unsound?  
  > **username_0**: Also, the method you describe needs material count, something that is not readily given by the PGN and evaluation score.  
  > **username_2**: Material count is easy to calculate given a PGN, right  
  > **username_3**: A well-placed pawn is worth more than a badly-placed bishop.  If one makes a move that nominally trades a pawn for a bishop, but does so in a way that the capturing pawn completely cuts an opponent's bishop out of the action, is that a "sacrifice"?  
  > **username_4**: Note that these "difficult to detect" sacrifices indicate flaws in the engine - if you're able to find such a condition manually you would want to bring it up to the developers of the engine you're using!  
  > **username_0**: Supercat, yes, even though it may not be a "brilliant" sacrifice, it is technically a sound sacrifice. But more interestingly, and I think this is what @username_1 meant, is that the engine (due to the inactivity of the bishop) might deem such sacrifice as sound yet it might in reality have been unsound strategically.  
  > **username_0**: @username_2 How can it be done? I want to program it using VBA in Excel. Is that easily done?  
  > **username_2**: A very simple method would be to search for the piece that last moved into the captured square (this will fail for en passant, but can be rectified with an additional conditional). Definitely doable in VBA. This will fail to account for the captures of rooks immediately after castling, but also can be rectified by replacing castling notation by rook moving to the corresponding square (king doesn't need to be tracked since they won't be captured)  
  > **username_0**: @username_2 Thank you! So do you recommend that after each move a position table (one that would have to change after each move) be looked up to see what piece was captured? Or should it be done with arrays?  
  > **username_2**: My first idea would be to split the first letter (with exceptions like castling and pawn moves) so you have the piece and the square it moves into, then you can do a lookup (array/map would work)  
  > **username_0**: @username_2 Thanks, I'll give it a try. I find it interesting that material information is not incorporated into evaluation tools as there is so much info that can be extracted about the player tendencies/skills from it. For example, it can reveal the player's sacrificing tendencies, how well they play depending on their material, and how much they prioritize position over material.  
  > **username_2**: I guess that's because people are more interested in how likely a position is to win, which is shown by the evaluation score instead of the material points.  
  > **username_0**: @username_2 I understand that the evaluation score is more important than the material score but I just think having both pieces of information in combination provides much greater insight into the player.  
  > **username_1**: @Wins9 almost all sound sacrifices would be caught- on occasion the engine may be wrong, however! It's probably fine, however.  
  
  ---
  
  