Answers.Body: <p>This answers your question by showing the pull White has. White's advantage is real. But I think it is important to notice how resilient a defender can be. This is a great example of how difficult it can be to win a "won" game. I am pretty sure Stockfish could beat me from either side of the board.</p>
  
  <p>The following is Stockfish 6 playing each side of the board, 5 minutes per move.</p>
  
  <pre><code>
  [FEN "r1bqk2r/2ppnp1p/p5p1/1p1P4/4P3/1BB2N2/P4PPP/3QK2R b Kkq - 0 1"]
  
  1...Rf8 2.Ng5 Ng8 3.h4 d6 4.Nxh7 Qe7 5.f3 Bd7 6.Nxf8 Qxf8 7.Qc1 f6 8.Bd2 Kd8 9.Ba5 Ke8 10.Qxc7 Nh6 11.O-O Qe7 12.Qb7 Rc8 13.Qxa6 Nf7 14.Qb6 Kf8 15.Re1 Qe5 16.Qf2 g5 17.Bd2 Kg8 18.hxg5 fxg5 19.f4 gxf4 20.Bxf4 Qg7 21.e5 dxe5 22.Bh2 Ng5 23.d6+ Kh7 24.Qh4+ Qh6 25.Qxh6+ Kxh6 26.Rxe5 Nh7 27.Bf4+ Kg6 28.Kf2 Bf5 29.Ke3 Nf6 30.Kd4 b4 31.Re7 Nd7 32.Bd2 Nb8 33.Kd5 Kf6 34.Bxb4 Nd7 35.a4 Nb6+ 36.Kd4 Nd7 37.Be1 Rc1 38.a5 Rc8 39.Bc4 Nb8 40.Bc3 Kg6 41.Kd5 Kg5 42.Rg7+ Kh5 43.Rc7 Rd8 44.Be2+
  </code></pre>
  
  <p>...and at this point Stockfish rated the position at +20. I wanted my computer back ;-)</p>
  
Answers.ContentLicense: CC BY-SA 3.0
Answers.CreationDate: 2018-03-12T08:14:38.970Z
Answers.Text: You could have had your computer back already around the tenth move, when White has an attack *and* the material advantage...
Answers.UserDisplayName: Evargalo
Answers.ContentLicense: CC BY-SA 3.0
Answers.CreationDate: 2018-03-12T10:54:15.390Z
Answers.Text: @Evargalo yeah but I was working outside. That's actually why I started the engine; I knew I had time.
Answers.UserDisplayName: Tony Ennis
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Answers.CreationDate: 2018-03-12T00:56:12.477Z
Answers.LastActivityDate: 2018-03-12T00:56:12.477Z
Answers.UserDisplayName: Tony Ennis
Answers.Body: <p>By material, white is down three pawns. (R+P vs B)  -3</p>
  
  <p>White has the bishop pair, which is ~pawn            1</p>
  
  <p>White has more space ~ 1/2 pawn                      1/2</p>
  
  <p>White has great lead in development ~pawn            1</p>
  
  <p>Black's king stuck in the middle ~pawn               1</p>
  
  <p>So the positional advantages outweigh the material deficit.</p>
  
  <p>Black's best moves are f6 and Rg8.  Both concede a pawn and, most likely an exchange due to the weakness of the dark squares(Ng5-h7-f6+).  Black will need at least four moves to castle to the queenside, and that leaves him still facing pressure down the half-open files.  The most important factor is that it's more difficult to defend than to attack, which increases white's value.  These elements shows that white is easily up by at least the value of a pawn.</p>
  
Answers.ContentLicense: CC BY-SA 3.0
Answers.CreationDate: 2018-03-11T16:14:57.707Z
Answers.Text: I assume just experience leads you to have these "point values" for those positional elements? Or is there some memorizable guidelines that can help a beginner like me? I would like to be able to see these positional advantages myself someday
Answers.UserDisplayName: Alexander Bird
Answers.ContentLicense: CC BY-SA 3.0
Answers.CreationDate: 2018-03-11T17:12:24.923Z
Answers.Text: I was taught that three tempi (moves) equal 1 pawn and that the bishop pair is worth between 1/2 - 1 pawn, depending on how open the position is.  The other two was only mentioned as an advantage.  A king trapped in the center--or a ruined castled position--is often considered to be worth at least two pawns.  For good examples, I suggest Alekhine's Best Games, his comments are clear and instructive.
Answers.UserDisplayName: Fred Knight
Answers.ContentLicense: CC BY-SA 3.0
Answers.CreationDate: 2018-03-11T17:52:02.470Z
Answers.Text: But white has a clear winning advantage in this position, not a 1/2 pawn advantage. Perhaps you should include "weak squares" in your evaluation. If the pawn from g6 was on g7 this should improve the position for black. In any case I would not rely solely on such assessment, particularly in very concrete tactical positions like this one.
Answers.UserDisplayName: user1583209
Answers.ContentLicense: CC BY-SA 3.0
Answers.CreationDate: 2018-03-11T20:54:12.150Z
Answers.Text: I don't think this kind of mechanistic "such-and-such a positional feature is worth so many pawns" is a good way of analyzing the game. If you can calculate like a computer, it works fine; but you can't, so it encourages memorizing "rules" rather than actually understanding. It might be better if the values quoted were from the actual engine's evaluation function but, even then, the question is about why "people" think White is winning.
Answers.UserDisplayName: David Richerby
Answers.ContentLicense: CC BY-SA 3.0
Answers.CreationDate: 2018-03-11T23:23:38.823Z
Answers.Text: I did say that the advantage was at least a pawn, I did mention the dark square weakness, and I did imply a concrete tactical line.  Do you really think that GMs calculate that far ahead?  They understand that various types of moves are worthwhile.  Translating into pawn values is just a simplistic way to convey the meanings.  Just like in the diagram, the c8-bishop isn't really worth the three pawns that were mechanically it was assigned--for the benefit of evaluating positions.  Finally, I included the psychological element.
Answers.UserDisplayName: Fred Knight
Answers.ContentLicense: CC BY-SA 3.0
Answers.CreationDate: 2018-03-12T07:33:11.323Z
Answers.Text: @FredKnight: Such static evaluations really only work in quiet position. Suggesting that you can evaluate the position here based on positional elements only is at least misleading. You could have the bishop pair, more space, a lead in development,... and still get mated next move.
Answers.UserDisplayName: user1583209
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Answers.CreationDate: 2018-03-12T07:47:32.297Z
Answers.Text: @user1583209:  I'm not suggesting that only positional elements are the only things to consider, but they are what offset the material imbalance.  By using reductio ad absurdum, we could say that we shouldn't play chess at all, because we could die at any moment.
Answers.UserDisplayName: Fred Knight
Answers.ContentLicense: CC BY-SA 3.0
Answers.CreationDate: 2018-03-12T08:20:32.067Z
Answers.Text: In the context of the question, we have chosen to play chess. Whether that was a good decision isn't what we're here to discuss. Having chosen to play chess, let's play it well.
Answers.UserDisplayName: David Richerby
Answers.ContentLicense: CC BY-SA 3.0
Answers.CreationDate: 2018-03-12T08:41:38.820Z
Answers.Text: @DavidRicherby Regarding your earlier comment about engine evaluations and such. It is worth pointing out that, while the engines use an evaluation function similar to what Fred Knight suggests, they do this for *many positions* that are *many moves down the line", which is a big difference to trying to judge the position by applying the evaluation function only on the current position.
Answers.UserDisplayName: user1583209
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Answers.CreationDate: 2018-03-12T09:11:39.850Z
Answers.Text: @user1583209 Completely agreed. That was one of the ideas I'd summarized as "If you can calculate like a computer".
Answers.UserDisplayName: David Richerby
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Answers.CreationDate: 2018-03-12T15:32:53.597Z
Answers.Text: @DavidRicherby To add, even if we're capable of calculating like a computer, whether all these positional elements are actually positive depends on the situation. Having more space can be bad if you cannot control it, a king in the middle (at the back) is sometimes safer than in the corner, the bishop pair is bad in a closed position and a lead in development need not be decisive if there are no weaknesses of the enemy to exploit.
Answers.UserDisplayName: Discrete lizard
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Answers.Text: -1 terrible answer.  This is how beginners analyze positions.
Answers.UserDisplayName: BlueRaja - Danny Pflughoeft
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Answers.UserDisplayName: Fred Knight
Answers.Body: <p>White has a lot of compensation for the sacrificed exchange, specifically:</p>
  
  <ul>
  <li><strong>more space</strong>: the white central pawns are perfectly placed to limit the movement of the black knight and bishop</li>
  <li><strong>play on the dark squares</strong>: black has considerably weakened the dark squares on the king side and does not have a dark-squared bishop anymore; White can easily take advantage of that by operating on these squares with bishop, knight and queen.</li>
  <li><strong>lead in development</strong>: Basically white only needs to activate the rook, while black really struggles to free himself. Also black will be forced to move the rook on h8 (castling seems too dangerous), losing another move for development and leaving the king in the center for some more time where it will be under attack.</li>
  </ul>
  
  <p>This suggests that white can make use of these elements, before black can recover.</p>
  
  <p>Somewhat concrete lines:</p>
  
  <p>Black's rook h8 is under attack and has to move. Three options:</p>
  
  <ol>
  <li>1...0-0 looks very dangerous for black. White could just play something like Qd2, Qh6, Ng5 and if necessary h4, h5. I don't see what black could do to avoid getting mated soon. Note that black cannot play something like f6 soon because of the discovered check from the b3 bishop.</li>
  <li>1..Rg8 or 1..Rf8. Here white has basically two ideas, which can be combined in various ways. a) play d6 which prevents black from playing d6 himself (freeing the bishop on c8) and allows white to activate the queen (via d6-f6). Also, with the white queen on d6 and the white bishop on f6, white would basically bind four black pieces (Qd8, Ne7, Ke8, Rf8) to very passive positions. b) play Ng5, which hints at an attack on f7 and also on re-routing the knight via h7 to f6.</li>
  </ol>
  
  <p>So overall, yes the position is pretty hopeless for black.</p>
  
  <hr>
  
  <p>Regarding your general quesion (<em>Why are these things worth three pawn points? And how do I know when they are worth that much?</em>):</p>
  
  <p>You should realize that material is only one of many factors relevant for judging  a position. Admittedly, in many games, players have somewhat symmetric positions, are developed equally well, etc and in this case, material becomes a major factor. So yes, in quiet normal positions material is often very important.</p>
  
  <p>However in highly unbalanced positions like the one in your example, material count becomes less important and is easily trumped by activity. There is no strict rule to know when this is the case. In fact this is among the more difficult aspects of chess and can basically only gained by experience. I would strongly discourage you from trying to assess such unbalanced positions by summing points for "piece activity", "weak king"... Chess just does not work this way.</p>
  
  <p>Computers do something like this in their evaluation function, but they do this for <em>many</em> (lots) positions <em>many</em> moves down the line (not only the current position) and then it does make sense. Furthermore computers have a more fine-grained number for "space", "piece activity", etc. </p>
  
  <p>Anyway, humans lack the power to do all this and basically need to rely on experience, intuition and (occasionally) calculating some more or less forced concrete lines.</p>
  
  <p>As a very rough guideline (don't follow this strictly) you can sacrifice:</p>
  
  <ul>
  <li><strong>a pawn</strong>: to gain a lead in development/piece activity or central control, for at least a short amount of time, often with a potential to regain the pawn easily if needed (see e.g. Queen's gambit). Sacrificing a pawn is not a major deal as many positions are still a draw +- a pawn.</li>
  <li><strong>up to three pawns or an exchange</strong>: if you get a major long term positional advantage through it; often you end up with a very strong minor piece vs. a not-so strong rook (e.g. in somewhat closed positions). Here you really need to have something concrete. </li>
  <li><strong>more than three pawns or an exchange</strong>: rarely, typically in direct mating attacks only</li>
  </ul>
  
Answers.ContentLicense: CC BY-SA 3.0
Answers.CreationDate: 2018-03-11T16:12:36.270Z
Answers.Text: To your point #1, after `13... O-O`, white could respond with `14. Qd5` which looks very very ugly for Black. Black has no control of the mating diagonal and the Q looks at `g7` and `h8`.
Answers.UserDisplayName: Tony Ennis
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Answers.CreationDate: 2018-03-11T17:54:35.943Z
Answers.Text: @TonyEnnis Yes, 14. Qd4 (which is what you meant) would be another option. In any case black certainly does not want to castle in this position.
Answers.UserDisplayName: user1583209
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Answers.CreationDate: 2018-03-12T08:12:49.967Z
Answers.Text: Actually, 13....0-0!? 14.Qd4 f6 15.d6 (not forced, but the most forcing and tempting) Kg7 16.de7 Qe7 17.0-0 Bb7 might one of the best practical chances for Black, giving back his material advantage to complete development.
Answers.UserDisplayName: Evargalo
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Answers.CreationDate: 2018-03-19T23:39:36.803Z
Answers.Text: All those things are good, but doesn't answer the intent of my question (and it's truly my bad for wording the question so poorly). The real question I meant is this: why are all those things (you said) worth a _material sacrifice_ of 3 pawn points!? I know your points are good, but how am I supposed to personally know they're _that_ good that I should be willing to sacrifice a major piece for a minor piece?
Answers.UserDisplayName: Alexander Bird
Answers.ContentLicense: CC BY-SA 3.0
Answers.CreationDate: 2018-03-20T02:59:24.967Z
Answers.Text: @AlexanderBird Material count is one positional factor out of many possible positional factors in a position. As with all positional factors it can be trumped by other positional factors; in the case of the given position, piece activity and coordination together with king safety are the most important positional factors, and they trump the simple material count. And black is outclassed in both of these vital positional factors in the given position. So, in order to know if a sacrifice is warranted you have to judge whether material count is trumped by other factors in the position.
Answers.UserDisplayName: Scounged
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Answers.LastActivityDate: 2018-03-20T08:38:19.343Z
Answers.LastEditDate: 2018-03-20T08:38:19.343Z
Answers.UserDisplayName: user1583209
Body: <p>I was given the below position in the US chess magazine. Author said this position is "hopeless for black". Lichess engine says 1.5 advantage for white.</p>
  
  <p>Why? I understand "piece points" are only a rule of thumb, but I also don't have any other heuristics to judge why white side is better. I assume that even though white is down material, she has a "positional advantage," but I don't know how to objectively discern why that is.</p>
  
  <p>Why would people say white has an advantage here?</p>
  
  <pre><code>[fen ""]
  
  1. e4 e5 2. Nf3 Nc6 3. Bb5 g6 4. c3 a6 5. Ba4 Bg7 6. d4 b5 7. Bb3 exd4 8. cxd4 Nge7 9. d5 Na5 10. Bd2 Bxb2 11. Bxa5 Bxa1 12. Nc3 Bxc3+ 13. Bxc3
  </code></pre>
  
  <p>EDIT</p>
  
  <p>The real question I meant to ask is this: why are all "these positional things" (space, development, castling rights, etc) worth a <em>material sacrifice</em> of 3 pawn points!? I know these principles are good, but how am I supposed to personally know they're <em>that</em> good that I should be willing to sacrifice a major piece for a minor piece?</p>
  
Comments.ContentLicense: CC BY-SA 3.0
Comments.CreationDate: 2018-03-11T15:38:10.250Z
Comments.Text: Also, i can't seem to get the moves to appear as an inline board. can someone let me know what I'm doing wrong?
Comments.UserDisplayName: Alexander Bird
Comments.ContentLicense: CC BY-SA 3.0
Comments.CreationDate: 2018-03-11T15:57:57.377Z
Comments.Text: I can see the board.
Comments.UserDisplayName: user1583209
Comments.ContentLicense: CC BY-SA 3.0
Comments.CreationDate: 2018-03-11T15:59:53.820Z
Comments.Text: Ok. Thanks.  I wonder if the phone app for stack exchange is different
Comments.UserDisplayName: Alexander Bird
Comments.ContentLicense: CC BY-SA 3.0
Comments.CreationDate: 2018-03-12T05:57:35.800Z
Comments.Text: The question title on Hot Network Questions is quite intriguing without the additional context...
Comments.UserDisplayName: user541686
Comments.ContentLicense: CC BY-SA 3.0
Comments.CreationDate: 2018-03-12T11:09:14.787Z
Comments.Text: @AlexanderBird, that's right, the app doesn't show chess diagrams. (At least the one for Android, which is the one I've tried.)
Comments.UserDisplayName: itub
Comments.ContentLicense: CC BY-SA 3.0
Comments.CreationDate: 2018-03-12T15:23:03.417Z
Comments.Text: @Mehrdad Is the chess symbol next to it not context enough?
Comments.UserDisplayName: Discrete lizard
Comments.ContentLicense: CC BY-SA 3.0
Comments.CreationDate: 2018-03-12T20:08:57.713Z
Comments.Text: @Discretelizard: I don't find it too conspicuous; it's easier to tell for non-beta sites.
Comments.UserDisplayName: user541686
Tags: <analysis><material-balance>
Title: How to objectively explain a positional advantage is worth a sacrifice (re: a specific example)
ThreadText: # How to objectively explain a positional advantage is worth a sacrifice (re: a specific example)
  
  (Asked by: username_0 on 2018-03-11)
  
  I was given the below position in the US chess magazine. Author said this position is "hopeless for black". Lichess engine says 1.5 advantage for white.
  
  Why? I understand "piece points" are only a rule of thumb, but I also don't have any other heuristics to judge why white side is better. I assume that even though white is down material, she has a "positional advantage," but I don't know how to objectively discern why that is.
  
  Why would people say white has an advantage here?
  
  ```
  [fen ""]
  
  1. e4 e5 2. Nf3 Nc6 3. Bb5 g6 4. c3 a6 5. Ba4 Bg7 6. d4 b5 7. Bb3 exd4 8. cxd4 Nge7 9. d5 Na5 10. Bd2 Bxb2 11. Bxa5 Bxa1 12. Nc3 Bxc3+ 13. Bxc3
  
  ```
  
  EDIT
  
  The real question I meant to ask is this: why are all "these positional things" (space, development, castling rights, etc) worth a *material sacrifice* of 3 pawn points!? I know these principles are good, but how am I supposed to personally know they're *that* good that I should be willing to sacrifice a major piece for a minor piece?
  
  **Tags:** analysis, material-balance
  
  > **Comments:**
  > **username_0**: Also, i can't seem to get the moves to appear as an inline board. can someone let me know what I'm doing wrong?  
  > **username_1**: I can see the board.  
  > **username_0**: Ok. Thanks.  I wonder if the phone app for stack exchange is different  
  > **username_2**: The question title on Hot Network Questions is quite intriguing without the additional context...  
  > **username_3**: @username_0, that's right, the app doesn't show chess diagrams. (At least the one for Android, which is the one I've tried.)  
  > **username_4**: @Mehrdad Is the chess symbol next to it not context enough?  
  > **username_2**: @username_4: I don't find it too conspicuous; it's easier to tell for non-beta sites.  
  
  ---
  
  ## 3 answers
  
  ### Answer by username_1 on 2018-03-11. Score: 13 | Accepted answer
  
  White has a lot of compensation for the sacrificed exchange, specifically:
  
  * **more space**: the white central pawns are perfectly placed to limit the movement of the black username_7 and bishop
  * **play on the dark squares**: black has considerably weakened the dark squares on the king side and does not have a dark-squared bishop anymore; White can easily take advantage of that by operating on these squares with bishop, username_7 and queen.
  * **lead in development**: Basically white only needs to activate the rook, while black really struggles to free himself. Also black will be forced to move the rook on h8 (castling seems too dangerous), losing another move for development and leaving the king in the center for some more time where it will be under attack.
  
  This suggests that white can make use of these elements, before black can recover.
  
  Somewhat concrete lines:
  
  Black's rook h8 is under attack and has to move. Three options:
  
  1. 1...0-0 looks very dangerous for black. White could just play something like Qd2, Qh6, Ng5 and if necessary h4, h5. I don't see what black could do to avoid getting mated soon. Note that black cannot play something like f6 soon because of the discovered check from the b3 bishop.
  2. 1..Rg8 or 1..Rf8. Here white has basically two ideas, which can be combined in various ways. a) play d6 which prevents black from playing d6 himself (freeing the bishop on c8) and allows white to activate the queen (via d6-f6). Also, with the white queen on d6 and the white bishop on f6, white would basically bind four black pieces (Qd8, Ne7, Ke8, Rf8) to very passive positions. b) play Ng5, which hints at an attack on f7 and also on re-routing the username_7 via h7 to f6.
  
  So overall, yes the position is pretty hopeless for black.
  
  ---
  
  Regarding your general quesion (*Why are these things worth three pawn points? And how do I know when they are worth that much?*):
  
  You should realize that material is only one of many factors relevant for judging a position. Admittedly, in many games, players have somewhat symmetric positions, are developed equally well, etc and in this case, material becomes a major factor. So yes, in quiet normal positions material is often very important.
  
  However in highly unbalanced positions like the one in your example, material count becomes less important and is easily trumped by activity. There is no strict rule to know when this is the case. In fact this is among the more difficult aspects of chess and can basically only gained by experience. I would strongly discourage you from trying to assess such unbalanced positions by summing points for "piece activity", "weak king"... Chess just does not work this way.
  
  Computers do something like this in their evaluation function, but they do this for *many* (lots) positions *many* moves down the line (not only the current position) and then it does make sense. Furthermore computers have a more fine-grained number for "space", "piece activity", etc.
  
  Anyway, humans lack the power to do all this and basically need to rely on experience, intuition and (occasionally) calculating some more or less forced concrete lines.
  
  As a very rough guideline (don't follow this strictly) you can sacrifice:
  
  * **a pawn**: to gain a lead in development/piece activity or central control, for at least a short amount of time, often with a potential to regain the pawn easily if needed (see e.g. Queen's gambit). Sacrificing a pawn is not a major deal as many positions are still a draw +- a pawn.
  * **up to three pawns or an exchange**: if you get a major long term positional advantage through it; often you end up with a very strong minor piece vs. a not-so strong rook (e.g. in somewhat closed positions). Here you really need to have something concrete.
  * **more than three pawns or an exchange**: rarely, typically in direct mating attacks only
  
  > **Comments:**
  > **username_5**: To your point #1, after `13... O-O`, white could respond with `14. Qd5` which looks very very ugly for Black. Black has no control of the mating diagonal and the Q looks at `g7` and `h8`.  
  > **username_1**: @username_5 Yes, 14. Qd4 (which is what you meant) would be another option. In any case black certainly does not want to castle in this position.  
  > **username_6**: Actually, 13....0-0!? 14.Qd4 f6 15.d6 (not forced, but the most forcing and tempting) Kg7 16.de7 Qe7 17.0-0 Bb7 might one of the best practical chances for Black, giving back his material advantage to complete development.  
  > **username_0**: All those things are good, but doesn't answer the intent of my question (and it's truly my bad for wording the question so poorly). The real question I meant is this: why are all those things (you said) worth a _material sacrifice_ of 3 pawn points!? I know your points are good, but how am I supposed to personally know they're _that_ good that I should be willing to sacrifice a major piece for a minor piece?  
  > **username_10**: @username_0 Material count is one positional factor out of many possible positional factors in a position. As with all positional factors it can be trumped by other positional factors; in the case of the given position, piece activity and coordination together with king safety are the most important positional factors, and they trump the simple material count. And black is outclassed in both of these vital positional factors in the given position. So, in order to know if a sacrifice is warranted you have to judge whether material count is trumped by other factors in the position.  
  
  ---
  
  ### Answer by username_5 on 2018-03-12. Score: 6
  
  This answers your question by showing the pull White has. White's advantage is real. But I think it is important to notice how resilient a defender can be. This is a great example of how difficult it can be to win a "won" game. I am pretty sure Stockfish could beat me from either side of the board.
  
  The following is Stockfish 6 playing each side of the board, 5 minutes per move.
  
  ```
  
  [FEN "r1bqk2r/2ppnp1p/p5p1/1p1P4/4P3/1BB2N2/P4PPP/3QK2R b Kkq - 0 1"]
  
  1...Rf8 2.Ng5 Ng8 3.h4 d6 4.Nxh7 Qe7 5.f3 Bd7 6.Nxf8 Qxf8 7.Qc1 f6 8.Bd2 Kd8 9.Ba5 Ke8 10.Qxc7 Nh6 11.O-O Qe7 12.Qb7 Rc8 13.Qxa6 Nf7 14.Qb6 Kf8 15.Re1 Qe5 16.Qf2 g5 17.Bd2 Kg8 18.hxg5 fxg5 19.f4 gxf4 20.Bxf4 Qg7 21.e5 dxe5 22.Bh2 Ng5 23.d6+ Kh7 24.Qh4+ Qh6 25.Qxh6+ Kxh6 26.Rxe5 Nh7 27.Bf4+ Kg6 28.Kf2 Bf5 29.Ke3 Nf6 30.Kd4 b4 31.Re7 Nd7 32.Bd2 Nb8 33.Kd5 Kf6 34.Bxb4 Nd7 35.a4 Nb6+ 36.Kd4 Nd7 37.Be1 Rc1 38.a5 Rc8 39.Bc4 Nb8 40.Bc3 Kg6 41.Kd5 Kg5 42.Rg7+ Kh5 43.Rc7 Rd8 44.Be2+
  
  ```
  
  ...and at this point Stockfish rated the position at +20. I wanted my computer back ;-)
  
  > **Comments:**
  > **username_6**: You could have had your computer back already around the tenth move, when White has an attack *and* the material advantage...  
  > **username_5**: @username_6 yeah but I was working outside. That's actually why I started the engine; I knew I had time.  
  
  ---
  
  ### Answer by username_7 on 2018-03-11. Score: 3
  
  By material, white is down three pawns. (R+P vs B) -3
  
  White has the bishop pair, which is ~pawn 1
  
  White has more space ~ 1/2 pawn 1/2
  
  White has great lead in development ~pawn 1
  
  Black's king stuck in the middle ~pawn 1
  
  So the positional advantages outweigh the material deficit.
  
  Black's best moves are f6 and Rg8. Both concede a pawn and, most likely an exchange due to the weakness of the dark squares(Ng5-h7-f6+). Black will need at least four moves to castle to the queenside, and that leaves him still facing pressure down the half-open files. The most important factor is that it's more difficult to defend than to attack, which increases white's value. These elements shows that white is easily up by at least the value of a pawn.
  
  > **Comments:**
  > **username_0**: I assume just experience leads you to have these "point values" for those positional elements? Or is there some memorizable guidelines that can help a beginner like me? I would like to be able to see these positional advantages myself someday  
  > **username_7**: I was taught that three tempi (moves) equal 1 pawn and that the bishop pair is worth between 1/2 - 1 pawn, depending on how open the position is.  The other two was only mentioned as an advantage.  A king trapped in the center--or a ruined castled position--is often considered to be worth at least two pawns.  For good examples, I suggest Alekhine's Best Games, his comments are clear and instructive.  
  > **username_1**: But white has a clear winning advantage in this position, not a 1/2 pawn advantage. Perhaps you should include "weak squares" in your evaluation. If the pawn from g6 was on g7 this should improve the position for black. In any case I would not rely solely on such assessment, particularly in very concrete tactical positions like this one.  
  > **username_8**: I don't think this kind of mechanistic "such-and-such a positional feature is worth so many pawns" is a good way of analyzing the game. If you can calculate like a computer, it works fine; but you can't, so it encourages memorizing "rules" rather than actually understanding. It might be better if the values quoted were from the actual engine's evaluation function but, even then, the question is about why "people" think White is winning.  
  > **username_7**: I did say that the advantage was at least a pawn, I did mention the dark square weakness, and I did imply a concrete tactical line.  Do you really think that GMs calculate that far ahead?  They understand that various types of moves are worthwhile.  Translating into pawn values is just a simplistic way to convey the meanings.  Just like in the diagram, the c8-bishop isn't really worth the three pawns that were mechanically it was assigned--for the benefit of evaluating positions.  Finally, I included the psychological element.  
  > **username_1**: @username_7: Such static evaluations really only work in quiet position. Suggesting that you can evaluate the position here based on positional elements only is at least misleading. You could have the bishop pair, more space, a lead in development,... and still get mated next move.  
  > **username_7**: @username_1:  I'm not suggesting that only positional elements are the only things to consider, but they are what offset the material imbalance.  By using reductio ad absurdum, we could say that we shouldn't play chess at all, because we could die at any moment.  
  > **username_8**: In the context of the question, we have chosen to play chess. Whether that was a good decision isn't what we're here to discuss. Having chosen to play chess, let's play it well.  
  > **username_1**: @username_8 Regarding your earlier comment about engine evaluations and such. It is worth pointing out that, while the engines use an evaluation function similar to what username_7 username_7 suggests, they do this for *many positions* that are *many moves down the line", which is a big difference to trying to judge the position by applying the evaluation function only on the current position.  
  > **username_8**: @username_1 Completely agreed. That was one of the ideas I'd summarized as "If you can calculate like a computer".  
  > **username_4**: @username_8 To add, even if we're capable of calculating like a computer, whether all these positional elements are actually positive depends on the situation. Having more space can be bad if you cannot control it, a king in the middle (at the back) is sometimes safer than in the corner, the bishop pair is bad in a closed position and a lead in development need not be decisive if there are no weaknesses of the enemy to exploit.  
  > **username_9**: -1 terrible answer.  This is how beginners analyze positions.  
  
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