Answers.Body: <p>As long as chess can't be calculated from beginning to end, it is very hard to scientifically prove an opening to be refuted (aside from lines that leave you with such hopeless situations like a bare king against king and rook, of course).</p>
  
  <p>If you are satisfied with a less scientific proof, I'd say gambits are even less so refuted. In my opinion, nearly all gambits are playable, as long as you won't play it against a superhuman database/program or a world champion. In a practical sense, probably no gambit worth of having a name is refuted in the sense of not being playable. Even if a gambit is widely considered unsound and often results in a worse position, it might contain enough steam to give your chess skill ample opportunities to overpower your opponent.I even remember a game where I suffered terrible against the BDG because I didn't find any refutation over the board. I only won because my opponent terribly misplayed the late midgame, but from the opening point of view he should have won the game.</p>
  
  <p>So my answer is: No gambit I know of is refuted to the degree of being unplayable.</p>
  
Answers.ContentLicense: CC BY-SA 3.0
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Answers.Text: See Latvian for a refuted gambit.
Answers.UserDisplayName: ferit
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Answers.Text: Can't downvote. King's Gambit is refuted.
Answers.UserDisplayName: Joshua
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Answers.Text: @ReinstateMonica: https://games.slashdot.org/story/12/04/02/2043240/rybka-solves-the-kings-gambit-chess-opening It's almost certainly correct despite some problems found that make it not quite a proof.
Answers.UserDisplayName: Joshua
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Answers.Text: @Joshua on the off chance that this was meant seriously: the kings gambit refutation article by Chessbase was an April's fools. We have nowhere near the calculation power needed to outright refute an opening. We don't even have the calculation power to prove that the starting position without a black queen is winning for White despite that being obviously true.
Answers.UserDisplayName: koedem
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Answers.CreationDate: 2012-05-02T11:51:12.487Z
Answers.LastActivityDate: 2012-05-02T14:28:08.987Z
Answers.LastEditDate: 2012-05-02T14:28:08.987Z
Answers.UserDisplayName: Ray
Answers.Body: <p>Many gambits are unsound. The proof is told by the number of these played at the highest levels of the game.  So, if you don't see the Blackmar-Diemer gambit at top tournaments, you can assume that its disadvantages outweigh its advantages.  The King's Gambit is one famously busted opening.</p>
  
  <p>That being said, we're not top players. Most of us can't beat the players who can't beat the top players.  I'd wager, charitably, that 75% of the moves we make are wrong, technically.</p>
  
  <p>In short, they're probably all playable.  As always, if you're going to take chances, book up first.  Understand the opening, know the main lines.</p>
  
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Answers.CreationDate: 2018-04-30T21:46:39.373Z
Answers.Text: An opening being rarely played at the top levels does not mean that it is busted. The King's Gambit is *not* busted. Busted means it should lose or draw nearly every time, and it doesn't, even at high levels. Its win rate is just not high enough to justify playing at that level.
Answers.UserDisplayName: Kef Schecter
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Answers.LastEditDate: 2012-06-10T01:16:16.023Z
Answers.UserDisplayName: Tony Ennis
Answers.Body: <p>I believe there are a few gambits completely solved, that is, analyzed up to positions that either the material advantage is enough to guarantee a win or this win is achieved by means of technique (if the final position is not directly checkmate). The only one that I know a proof of, however, is the Latvian Gambit:</p>
  
  <pre><code>[FEN ""]
  1.e4 e5 2. Nf3 f5
  </code></pre>
  
  <p>The Spanish analyst Alejandro Melchor provides two very insightful .pgn with what he considers to be the refutation of said defense. <a href="http://www.filedropper.com/leton1" rel="noreferrer">Here</a> you may download the first one and <a href="http://www.filedropper.com/leton2" rel="noreferrer">here</a> you may download the second one. He also wrote an <a href="http://www.filedropper.com/apend" rel="noreferrer">appendix</a>.</p>
  
  <p>They both are deep in calculations and very detailed, if you ever want to play perfect chess against this gambit, then good luck. Even if a gambit is "refuted", not many know these lines and the ensuing complications. This makes almost any gambit, refuted or not, completely playable (provided you are not facing a super-GM).</p>
  
  <p>P.D.: I had to upload the files via a third party, I hopes it's not inconvenient, since I don't know if it's possible to upload files directly via Stackexchange.</p>
  
Answers.ContentLicense: CC BY-SA 3.0
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Answers.Text: This is Damianos Defence. The Latvian Gambit is 1.e4 e5 2. Nf5 f5
Answers.UserDisplayName: Philip Roe
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Answers.CreationDate: 2018-04-25T14:04:22.770Z
Answers.Text: The move 2. Nf5 is illegal.
Answers.UserDisplayName: Pablo S. Ocal
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Answers.LastEditDate: 2014-09-20T17:36:18.477Z
Answers.UserDisplayName: Pablo S. Ocal
Answers.Body: <p>Here is an article that describes a way to compare (and refute) chess openings.</p>
  
  <p><a href="http://papers.ssrn.com/sol3/papers.cfm?abstract_id=2415203" rel="nofollow">http://papers.ssrn.com/sol3/papers.cfm?abstract_id=2415203</a></p>
  
Answers.ContentLicense: CC BY-SA 3.0
Answers.CreationDate: 2014-04-04T22:52:24.317Z
Answers.Text: Byron, could you say a bit more about the content of that paper? Links can die/rot, so it's best if answers include more info about any linked content.
Answers.UserDisplayName: ETD
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Answers.CreationDate: 2014-04-04T12:57:52.173Z
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Answers.UserDisplayName: Byron Bose
Answers.Body: <p>The <a href="https://en.wikipedia.org/wiki/Damiano_Defence" rel="nofollow noreferrer">Damiano Defense</a>, also known as the five pawns gambit, is practically refuted. You can find the details on the Wikipedia page. The key line is:</p>
  <ol>
  <li>e4 e5 2. Nf3 f6? 3. Nxe5! fxe5? 4. Qh5+ Ke7 5. Qxe5+ Kf7 6. Bc4+ d5 7. Bxd5+ Kg6 8. h4 h5 9. Bxb7</li>
  </ol>
  <p>After which Black cannot stop Bxa8 with a decisive material advantage for White.</p>
  
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Answers.UserDisplayName: Allure
Body: <p>I've stumbled upon <a href="http://www.jeremysilman.com/chess_bits_pieces/110103_blackmar_dmr_gmbt.html" rel="noreferrer">this article</a> a while ago, and I've also seen refutations for the Muzio Gambit (Joseph Kling &amp; Bernard Horwitz - Chess Studies on Endings of Games). I'm wondering what other gambits are proven to be unsound.</p>
  
  <p>Edit: I'm looking for refuted gambits in the strict sense of the word, followed by proof. Even though a gambit might be playable against someone who doesn't know its refutation, the gambit is still considered refuted if it is proven that the side who initiated the gambit loses in all variations worth looking at against best play. So yes, I'm looking for scientific proof.</p>
  
  <p>Also, if a database of almost all games played in a particular gambit shows that the side that initiated the gambit wins almost all the time, this doesn't mean that there isn't a way for that gambit to be refuted, it just means that if there is a way, most people haven't played it.</p>
  
  <p>Above everything, I'm looking for material to learn from. <a href="http://en.chessbase.com/post/rajlich-busting-the-king-s-gambit-this-time-for-sure" rel="noreferrer">An article that says that Vasik Rajlich or someone else has used a computer cluster</a> and came to a conclusion regarding a certain position, how will I benefit from it if there is no proof? <strong>(And please note that that King's-Gambit-busted-by-Rajlich article was in fact a Chessbase <a href="http://en.chessbase.com/post/the-chebase-april-fool-s-prank" rel="noreferrer">April Fools' joke!</a>)</strong></p>
  
Tags: <opening><analysis><theory><gambits><evaluation>
Title: What proofs for refuted gambits are there?
ThreadText: # What proofs for refuted gambits are there?
  
  (Asked by: username_0 on 2012-05-02)
  
  I've stumbled upon [this article](http://www.jeremysilman.com/chess_bits_pieces/110103_blackmar_dmr_gmbt.html) a while ago, and I've also seen refutations for the Muzio Gambit (Joseph Kling & Bernard Horwitz - Chess Studies on Endings of Games). I'm wondering what other gambits are proven to be unsound.
  
  Edit: I'm looking for refuted gambits in the strict sense of the word, followed by proof. Even though a gambit might be playable against someone who doesn't know its refutation, the gambit is still considered refuted if it is proven that the side who initiated the gambit loses in all variations worth looking at against best play. So yes, I'm looking for scientific proof.
  
  Also, if a database of almost all games played in a particular gambit shows that the side that initiated the gambit wins almost all the time, this doesn't mean that there isn't a way for that gambit to be refuted, it just means that if there is a way, most people haven't played it.
  
  Above everything, I'm looking for material to learn from. [An article that says that Vasik Rajlich or someone else has used a computer cluster](http://en.chessbase.com/post/rajlich-busting-the-king-s-gambit-this-time-for-sure) and came to a conclusion regarding a certain position, how will I benefit from it if there is no proof? **(And please note that that King's-Gambit-busted-by-Rajlich article was in fact a Chessbase [April Fools' joke!](http://en.chessbase.com/post/the-chebase-april-fool-s-prank))**
  
  **Tags:** opening, analysis, theory, gambits, evaluation
  
  
  ---
  
  ## 5 answers
  
  ### Answer by username_1 on 2012-05-02. Score: 16
  
  As long as chess can't be calculated from beginning to end, it is very hard to scientifically prove an opening to be refuted (aside from lines that leave you with such hopeless situations like a bare king against king and rook, of course).
  
  If you are satisfied with a less scientific proof, I'd say gambits are even less so refuted. In my opinion, nearly all gambits are playable, as long as you won't play it against a superhuman database/program or a world champion. In a practical sense, probably no gambit worth of having a name is refuted in the sense of not being playable. Even if a gambit is widely considered unsound and often results in a worse position, it might contain enough steam to give your chess skill ample opportunities to overpower your opponent.I even remember a game where I suffered terrible against the BDG because I didn't find any refutation over the board. I only won because my opponent terribly misplayed the late midgame, but from the opening point of view he should have won the game.
  
  So my answer is: No gambit I know of is refuted to the degree of being unplayable.
  
  > **Comments:**
  > **username_2**: See Latvian for a refuted gambit.  
  > **username_3**: Can't downvote. King's Gambit is refuted.  
  > **username_3**: @ReinstateMonica: https://games.slashdot.org/story/12/04/02/2043240/rybka-solves-the-kings-gambit-chess-opening It's almost certainly correct despite some problems found that make it not quite a proof.  
  > **username_4**: @username_3 on the off chance that this was meant seriously: the kings gambit refutation article by Chessbase was an April's fools. We have nowhere near the calculation power needed to outright refute an opening. We don't even have the calculation power to prove that the starting position without a black queen is winning for White despite that being obviously true.  
  
  ---
  
  ### Answer by username_5 on 2012-05-02. Score: 10
  
  Many gambits are unsound. The proof is told by the number of these played at the highest levels of the game. So, if you don't see the Blackmar-Diemer gambit at top tournaments, you can assume that its disadvantages outweigh its advantages. The King's Gambit is one famously busted opening.
  
  That being said, we're not top players. Most of us can't beat the players who can't beat the top players. I'd wager, charitably, that 75% of the moves we make are wrong, technically.
  
  In short, they're probably all playable. As always, if you're going to take chances, book up first. Understand the opening, know the main lines.
  
  > **Comments:**
  > **username_6**: An opening being rarely played at the top levels does not mean that it is busted. The King's Gambit is *not* busted. Busted means it should lose or draw nearly every time, and it doesn't, even at high levels. Its win rate is just not high enough to justify playing at that level.  
  
  ---
  
  ### Answer by username_7 on 2014-09-20. Score: 6
  
  I believe there are a few gambits completely solved, that is, analyzed up to positions that either the material advantage is enough to guarantee a win or this win is achieved by means of technique (if the final position is not directly checkmate). The only one that I know a proof of, however, is the Latvian Gambit:
  
  ```
  [FEN ""]
  1.e4 e5 2. Nf3 f5
  
  ```
  
  The Spanish analyst Alejandro Melchor provides two very insightful .pgn with what he considers to be the refutation of said defense. [Here](http://www.filedropper.com/leton1) you may download the first one and [here](http://www.filedropper.com/leton2) you may download the second one. He also wrote an [appendix](http://www.filedropper.com/apend).
  
  They both are deep in calculations and very detailed, if you ever want to play perfect chess against this gambit, then good luck. Even if a gambit is "refuted", not many know these lines and the ensuing complications. This makes almost any gambit, refuted or not, completely playable (provided you are not facing a super-GM).
  
  P.D.: I had to upload the files via a third party, I hopes it's not inconvenient, since I don't know if it's possible to upload files directly via Stackexchange.
  
  > **Comments:**
  > **username_8**: This is Damianos Defence. The Latvian Gambit is 1.e4 e5 2. Nf5 f5  
  > **username_7**: The move 2. Nf5 is illegal.  
  
  ---
  
  ### Answer by username_9 on 2014-04-04. Score: 3
  
  Here is an article that describes a way to compare (and refute) chess openings.
  
  <http://papers.ssrn.com/sol3/papers.cfm?abstract_id=2415203>
  
  > **Comments:**
  > **username_10**: username_9, could you say a bit more about the content of that paper? Links can die/rot, so it's best if answers include more info about any linked content.  
  
  ---
  
  ### Answer by username_11 on 2020-09-07. Score: 1
  
  The [Damiano Defense](https://en.wikipedia.org/wiki/Damiano_Defence), also known as the five pawns gambit, is practically refuted. You can find the details on the Wikipedia page. The key line is:
  
  1. e4 e5 2. Nf3 f6? 3. Nxe5! fxe5? 4. Qh5+ Ke7 5. Qxe5+ Kf7 6. Bc4+ d5 7. Bxd5+ Kg6 8. h4 h5 9. Bxb7
  
  After which Black cannot stop Bxa8 with a decisive material advantage for White.
  
  
  ---
  
  