Answers.Body: <p>The first English definition of blunder I see is "a stupid or careless mistake", and that's how I have always perceived the term in chess. It's not the severity of the error that matters so much as how silly and avoidable it is. If you played a move that takes the evaluation from 0 to -10 because you missed all the implications of a spectacular sacrifice that needed to be calculated out to 10 moves to verify its soundness, that's not a blunder, but if you played a move that takes the evaluation from 0 to -1 because you just didn't notice that a pawn was hanging, that is a blunder.</p>
  
Answers.ContentLicense: CC BY-SA 3.0
Answers.CreationDate: 2014-10-06T08:58:28.917Z
Answers.Text: +1, this is how I've heard the term used. If the player who made a mistake can't easily see why the move was bad after someone points it out, it's never called a blunder, even if the mistake was very bad.
Answers.UserDisplayName: JiK
Answers.ContentLicense: CC BY-SA 3.0
Answers.CreationDate: 2014-10-06T12:20:13.080Z
Answers.Text: It's gotten a couple of downvotes, so I guess our mutual understanding of the term is not universal!
Answers.UserDisplayName: dfan
Answers.ContentLicense: CC BY-SA 3.0
Answers.CreationDate: 2014-10-05T01:05:19.717Z
Answers.LastActivityDate: 2014-10-05T01:05:19.717Z
Answers.UserDisplayName: dfan
Answers.Body: <p>A blunder is a move that gives your opponent enough of an advantage to win, or to get a draw after you should have won.</p>
  
  <p>As someone else pointed out, it depends on the skill level. At a high level, the "loss" of a move or a key square may be a blunder. For intermediate players, maybe the loss of a pawn, and for beginners, maybe one or more pieces.</p>
  
  <p>That is, these "advantages" are large enough, relative to the skill level, that upon seeing one of them, you can reasonably predict the likely winner.</p>
  
Answers.ContentLicense: CC BY-SA 3.0
Answers.CreationDate: 2014-10-05T14:09:59.000Z
Answers.Text: Isn't also a blunder to misplay a winning position and transform it into a draw?
Answers.UserDisplayName: Pablo S. Ocal
Answers.ContentLicense: CC BY-SA 3.0
Answers.CreationDate: 2014-10-05T14:16:16.530Z
Answers.Text: @pablo: Added "or to get a draw after you should have won." to first line.
Answers.UserDisplayName: Tom Au
Answers.ContentLicense: CC BY-SA 3.0
Answers.CreationDate: 2014-10-06T12:23:53.223Z
Answers.Text: I'd say it's also blunder to transform a easily won position to a (still winning) position where a hard fight is needed for a win (for example, missing a mate in one in an advantageous endgame). It looks like you disagree; is that so?
Answers.UserDisplayName: JiK
Answers.ContentLicense: CC BY-SA 3.0
Answers.CreationDate: 2014-10-06T13:30:58.640Z
Answers.Text: @JiK: We're all human, and no one plays perfectly. To me, a blunder is where you play "below your level" and that of your opponent. So losing a pawn wouldn't really be a blunder for a beginner, but would be for me, an intermediate player. Likewise, I wouldn't "fault" myself for losing a move or a square, but would fault a GM.
Answers.UserDisplayName: Tom Au
Answers.ContentLicense: CC BY-SA 3.0
Answers.CreationDate: 2014-10-06T13:36:32.347Z
Answers.Text: @TomAu I'm sorry, I don't see how your comment is related to my question.
Answers.UserDisplayName: JiK
Answers.ContentLicense: CC BY-SA 3.0
Answers.CreationDate: 2014-10-06T13:41:27.613Z
Answers.Text: @JiK: You asked me if I disagreed with your formulation. I've told you what I consider a blunder. So you can compare the two and draw your own conclusion.
Answers.UserDisplayName: Tom Au
Answers.ContentLicense: CC BY-SA 3.0
Answers.CreationDate: 2014-10-06T14:31:37.310Z
Answers.Text: @TomAu Then I don't see why your formulation in the comment is different than in the answer.
Answers.UserDisplayName: JiK
Answers.ContentLicense: CC BY-SA 3.0
Answers.CreationDate: 2014-10-05T01:00:27.940Z
Answers.LastActivityDate: 2014-10-05T14:15:47.837Z
Answers.LastEditDate: 2014-10-05T14:15:47.837Z
Answers.UserDisplayName: Tom Au
Answers.Body: <p>This is an interesting question. It seems  that the higher the skill level, the less it takes to consider something a blunder. A GM may consider getting double pawns in a certain position a blunder while weaker players may just see it as a mistake or may not even call it a bad move. So how you call a blunder depends on your skill level because higher level players can better take advantage of all ranges of mistakes compared to weaker players. </p>
  
Answers.ContentLicense: CC BY-SA 3.0
Answers.CreationDate: 2014-10-04T22:02:48.407Z
Answers.LastActivityDate: 2014-10-04T22:02:48.407Z
Answers.UserDisplayName: GuRoux _
Body: <p>I am looking for a precise definition for a blunder. Computers often flag moves as blunders for any move that loses a point advantage or more. But what if I am completely winning and I decide to simplify the game by "sacrificing" my material plus. The computer may say that I lost more than a point advantage, but am I not more likely to win? There is also the scenario where a move may improve your position as evaluated by the computer but greatly decreases your chance of winning. Thus, I am interested in opinions on defining a better definition of a blunder than the computer uses.</p>
  
Comments.ContentLicense: CC BY-SA 3.0
Comments.CreationDate: 2014-10-05T06:48:59.247Z
Comments.Text: The best way to learn things is on examples so in addition to those great definitions cited by collegues above I'm just going to paste you this:
  http://www.youtube.com/watch?v=TY41yF1gX1w
  as a greatest example of what blunder is.
Comments.UserDisplayName: Pijotrek
Comments.ContentLicense: CC BY-SA 3.0
Comments.CreationDate: 2014-10-05T14:42:42.093Z
Comments.Text: After you have decided on a definition, you may also edit the [tag:blunder] tag wiki.
Comments.UserDisplayName: Dag Oskar Madsen
Tags: <terminology><blunder>
Title: What is a blunder?
ThreadText: # What is a blunder?
  
  (Asked by: username_0 on 2014-10-04)
  
  I am looking for a precise definition for a blunder. Computers often flag moves as blunders for any move that loses a point advantage or more. But what if I am completely winning and I decide to simplify the game by "sacrificing" my material plus. The computer may say that I lost more than a point advantage, but am I not more likely to win? There is also the scenario where a move may improve your position as evaluated by the computer but greatly decreases your chance of winning. Thus, I am interested in opinions on defining a better definition of a blunder than the computer uses.
  
  **Tags:** terminology, blunder
  
  > **Comments:**
  > **username_1**: The best way to learn things is on examples so in addition to those great definitions cited by collegues above I'm just going to paste you this: http://www.youtube.com/watch?v=TY41yF1gX1w as a greatest example of what blunder is.  
  > **username_2**: After you have decided on a definition, you may also edit the [tag:blunder] tag wiki.  
  
  ---
  
  ## 3 answers
  
  ### Answer by username_3 on 2014-10-05. Score: 8
  
  The first English definition of blunder I see is "a stupid or careless mistake", and that's how I have always perceived the term in chess. It's not the severity of the error that matters so much as how silly and avoidable it is. If you played a move that takes the evaluation from 0 to -10 because you missed all the implications of a spectacular sacrifice that needed to be calculated out to 10 moves to verify its soundness, that's not a blunder, but if you played a move that takes the evaluation from 0 to -1 because you just didn't notice that a pawn was hanging, that is a blunder.
  
  > **Comments:**
  > **username_4**: +1, this is how I've heard the term used. If the player who made a mistake can't easily see why the move was bad after someone points it out, it's never called a blunder, even if the mistake was very bad.  
  > **username_3**: It's gotten a couple of downvotes, so I guess our mutual understanding of the term is not universal!  
  
  ---
  
  ### Answer by username_5 on 2014-10-05. Score: 3
  
  A blunder is a move that gives your opponent enough of an advantage to win, or to get a draw after you should have won.
  
  As someone else pointed out, it depends on the skill level. At a high level, the "loss" of a move or a key square may be a blunder. For intermediate players, maybe the loss of a pawn, and for beginners, maybe one or more pieces.
  
  That is, these "advantages" are large enough, relative to the skill level, that upon seeing one of them, you can reasonably predict the likely winner.
  
  > **Comments:**
  > **username_6**: Isn't also a blunder to misplay a winning position and transform it into a draw?  
  > **username_5**: @username_6: Added "or to get a draw after you should have won." to first line.  
  > **username_4**: I'd say it's also blunder to transform a easily won position to a (still winning) position where a hard fight is needed for a win (for example, missing a mate in one in an advantageous endgame). It looks like you disagree; is that so?  
  > **username_5**: @username_4: We're all human, and no one plays perfectly. To me, a blunder is where you play "below your level" and that of your opponent. So losing a pawn wouldn't really be a blunder for a beginner, but would be for me, an intermediate player. Likewise, I wouldn't "fault" myself for losing a move or a square, but would fault a GM.  
  > **username_4**: @username_5 I'm sorry, I don't see how your comment is related to my question.  
  > **username_5**: @username_4: You asked me if I disagreed with your formulation. I've told you what I consider a blunder. So you can compare the two and draw your own conclusion.  
  > **username_4**: @username_5 Then I don't see why your formulation in the comment is different than in the answer.  
  
  ---
  
  ### Answer by username_7 on 2014-10-04. Score: 3
  
  This is an interesting question. It seems that the higher the skill level, the less it takes to consider something a blunder. A GM may consider getting double pawns in a certain position a blunder while weaker players may just see it as a mistake or may not even call it a bad move. So how you call a blunder depends on your skill level because higher level players can better take advantage of all ranges of mistakes compared to weaker players.
  
  
  ---
  
  