Answers.Body: <p>My answer is going to be a bit vague, because I know nothing about your skills and knowledge. It’s basically a riff on the way Aleksander Wojtkiewicz approached playing in open tournaments.</p>
  <p>First, you’ll want to be playing towards middlegame positions you are comfortable with playing, regardless of opponent. Which ones those are will be unique to you.</p>
  <p>Against weaker players, choose variations that limit your risk, and rely on your own better understanding of chess to carry you to victory. By selecting less double-edged lines you both limit the likelihood you will destroy your own game with a mistake, and increase the likelihood your opponent <em>will</em> self-destruct. (After all, the simple reason they’re lower rated is because they’re more likely to blunder than you are. Wear them down and wait for the gift.)</p>
  <p>Against stronger players, choose more enterprising lines. In a long, slow game against a higher rated player, the “blunder ratio” will be tilted against you, so you want instead a tense battle where it’s difficult to come back from a mistake. The odds you can win a grind-it-out game against a player with better technique are lower than the odds they’ll make a mistake against you in a knife-edged position, giving you an opening for a win.</p>
  <p>These variations can coexist within the same opening, or be from completely different openings. Depends on what you like, what positions you play well.</p>
  
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Answers.CreationDate: 2023-05-23T18:23:36.827Z
Answers.LastActivityDate: 2023-05-23T18:23:36.827Z
Answers.UserDisplayName: Arlen
Answers.Body: <blockquote>
  <p>Which kinds of openings are good against much stronger opponents?</p>
  </blockquote>
  <p>Openings where you know them the best and are most familiar with the plans arising from the openings.</p>
  <blockquote>
  <p>Which kinds of openings are good against much weaker opponents?</p>
  </blockquote>
  <p>Openings where you know them the best and are most familiar with the plans arising from the openings.</p>
  <p>Look, in any situation the best openings are dependent completely on the individual playing them.</p>
  <p>If you deviate from playing the openings you know best (including the plans arising from them) then you are deliberately choosing to play openings which are inferior for you, where you will have a smaller advantage against a weaker player and bigger disadvantage against a stronger player.</p>
  <p>Of course, if you are trying to learn a new opening then you have to go through a period where you are deliberately handicapping yourself until you get to know the opening and its plans really well, but that's the price for extending your repertoire.</p>
  
Answers.ContentLicense: CC BY-SA 4.0
Answers.CreationDate: 2023-05-22T17:59:10.340Z
Answers.Text: If I played openings that I don't know very well, I wouldn't score very well. Yes, that's obviously true. But my idea is to have two opening repertoires, and I would learn and know very well all the openings in my two repertoires.
Answers.UserDisplayName: Fate
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Answers.CreationDate: 2023-05-22T18:47:51.620Z
Answers.Text: @Fate You are missing the point. All your opponents, weak or strong, are unique individuals. They play lots of different openings irrespective of their strength. What works against one weak opponent, because they don't know it, will fail badly against another weak opponent because they play it all the time. Your idea of avoiding openings which could be drawish is also wrong. A few years ago I played the black side of a Slav against a player 350 FIDE rating points higher than me.  He played the "drawish" exchange variation and lost.
Answers.UserDisplayName: Brian Towers
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Answers.CreationDate: 2023-05-22T19:32:46.733Z
Answers.Text: Of course all opponents are unique individuals, but what matters here are statistical averages, not individual cases. "Opening X is particularly good against much stronger players" means that, if I pick opening X in my repertoire against much stronger players, statistically, on average, my expected average playing strength against much stronger opponents will be say for example 50 Elo more than usual.
Answers.UserDisplayName: Fate
Answers.ContentLicense: CC BY-SA 4.0
Answers.CreationDate: 2023-05-22T19:33:47.777Z
Answers.Text: If we look at individual cases: Against a much stronger player who studied opening X extremely deeply, my expected playing strength will be 50 Elo less than usual. Against a much stronger player who never studied opening X, my expected playing strength will be 150 Elo more than usual. But ON AVERAGE, my expected playing strength will be 50 Elo more than usual, which is why opening X is particularly good against much stronger players.
Answers.UserDisplayName: Fate
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Answers.UserDisplayName: Brian Towers
Body: <p>I had an idea: build two opening repertoires, one good against much stronger opponents, and one good against much weaker opponents.</p>
  <p>So two questions:</p>
  <ul>
  <li>Which kinds of openings are good against much stronger opponents?</li>
  <li>Which kinds of openings are good against much weaker opponents?</li>
  </ul>
  <p>.</p>
  <ul>
  <li>Mainlines or sidelines?</li>
  <li>Open or closed?</li>
  <li>Tactical or positional?</li>
  <li>Sharp or slow?</li>
  <li>Chaotic or quiet?</li>
  <li>Theory-heavy or theory-light?</li>
  </ul>
  <p>When playing against much weaker opponents, an opening can be good either because it maximizes your winning probability (or more precisely the winning probability plus half of the drawing probability) or because it allows you to relax and play on autopilot without needing to focus intensely.</p>
  <p>Against much weaker opponents, Black should probably not play the French and the Slav, because this would allow White to play the drawish Exchange variations, and a draw would be a bad result for the much stronger player (though of course still not as bad as a loss).</p>
  <p>What about the London + Caro-Kann + Slav with ...Bf5, a system which I currently play, is this system good against stronger or weaker opponents?</p>
  <p>I did some research on ChessBase, and the conclusion is that surprisingly a very large rating gap does not alter the usual frequencies at which openings are played. Which proves that when they face much stronger or much weaker opponents, almost no one tries to exploit the gap in strength by choosing specific openings. E.g. When White is much stronger than Black, White doesn't play 1.e4 2.Qh5 at a much higher frequency than usual.</p>
  
Comments.ContentLicense: CC BY-SA 4.0
Comments.CreationDate: 2023-05-22T16:13:02.880Z
Comments.Text: Doesn't really answer your question, but three factors that are good to consider at any level: objective strength of an opening, how comfortable you are with it, and how well-versed you anticipate your opponent will be with the theory.
Comments.UserDisplayName: Inertial Ignorance
Comments.ContentLicense: CC BY-SA 4.0
Comments.CreationDate: 2023-05-22T19:13:50.900Z
Comments.Text: My goal in the opening is to get to a structure I prefer and know the plans and timing well.
Comments.UserDisplayName: Michael West
Comments.ContentLicense: CC BY-SA 4.0
Comments.CreationDate: 2023-05-22T21:39:43.523Z
Comments.Text: Probably almost anything will work against much weaker opponents -- and therefore, almost nothing will against much stronger opponents. They're much weaker / stronger, you'll win / lose almost all the time. Openings don't influence that much.
Comments.UserDisplayName: RemcoGerlich
Comments.ContentLicense: CC BY-SA 4.0
Comments.CreationDate: 2023-05-22T21:49:16.830Z
Comments.Text: @RemcoGerlich: True, regardless of what opening you play, against a much stronger (resp. weaker) player you will almost always lose (resp. win). But having two repertoires would increase your winning probability against much stronger players from 1% to 2% and decrease your losing probability against much weaker players from 2% to 1%. A 1% change would usually be completely insignificant, but here it is not. Whether your winning probability is 50% or 51% makes a difference of only 7 Elo. But whether your winning probability is 1% or 2% makes a huge difference, a 120 Elo difference.
Comments.UserDisplayName: Fate
Comments.ContentLicense: CC BY-SA 4.0
Comments.CreationDate: 2023-05-22T21:53:42.587Z
Comments.Text: Let's say those numbers are true. I just don't see why it would be a good use of your time to learn two entire repertoires to change the result of 1% of the games the 10% of the time you play against a much weaker or much stronger opponent.
Comments.UserDisplayName: RemcoGerlich
Comments.ContentLicense: CC BY-SA 4.0
Comments.CreationDate: 2023-05-22T22:55:46.120Z
Comments.Text: @RemcoGerlich: How valuable changing the result of a game is heavily depends on the rating difference. Imagine that your next three opponents were one super-GM and two players who have the same rating as you. Would you rather win against the super-GM and lose against the other two, or lose against the super-GM and win against the other two?
Comments.UserDisplayName: Fate
Comments.ContentLicense: CC BY-SA 4.0
Comments.CreationDate: 2023-05-22T22:56:29.163Z
Comments.Text: @RemcoGerlich: Imagine two players: the first plays only against opponents who are much stronger (800 Elo) than him and so he wins only 1% of the time, the second plays only against players who have the same rating as him and so he wins 50% of the time. "to change the result of 1% of the games" would be extremely valuable for the first player but not valuable for the second player. "to change the result of 1% of the games" would increase the first player's rating by 120 Elo, but it would only increase the second player's rating by 7 Elo.
Comments.UserDisplayName: Fate
Comments.ContentLicense: CC BY-SA 4.0
Comments.CreationDate: 2023-05-22T22:57:26.833Z
Comments.Text: "the 10% of the time you play against a much weaker or much stronger opponent" > It could be more than 10%. It could be anything really. I could choose to exclusively play only against much stronger or much weaker players, in which case the percentage would be 100%. Or I could choose to exclusively play only against players who have roughly the same rating as me, in which case the percentage would be 0%. If I meet a random dude IRL and he happens to know how to play chess, statistically he's probably gonna be less than 1200 Elo so he's gonna be much weaker than me.
Comments.UserDisplayName: Fate
Comments.ContentLicense: CC BY-SA 4.0
Comments.CreationDate: 2023-05-23T03:32:24.517Z
Comments.Text: If White is much stronger than Black, there is even less reason than usual to try something like 1.e4 e5 2.Qh5. The rule is, against a much weaker opponent, play solid positional chess; against a much stronger opponent, the opposite.
Comments.UserDisplayName: bof
Tags: <opening>
Title: Which kinds of openings are good against much stronger and much weaker opponents?
ThreadText: # Which kinds of openings are good against much stronger and much weaker opponents?
  
  (Asked by: username_0 on 2023-05-22)
  
  I had an idea: build two opening repertoires, one good against much stronger opponents, and one good against much weaker opponents.
  
  So two questions:
  
  * Which kinds of openings are good against much stronger opponents?
  * Which kinds of openings are good against much weaker opponents?
  
  .
  
  * Mainlines or sidelines?
  * Open or closed?
  * Tactical or positional?
  * Sharp or slow?
  * Chaotic or quiet?
  * Theory-heavy or theory-light?
  
  When playing against much weaker opponents, an opening can be good either because it maximizes your winning probability (or more precisely the winning probability plus half of the drawing probability) or because it allows you to relax and play on autopilot without needing to focus intensely.
  
  Against much weaker opponents, Black should probably not play the French and the Slav, because this would allow White to play the drawish Exchange variations, and a draw would be a bad result for the much stronger player (though of course still not as bad as a loss).
  
  What about the London + Caro-Kann + Slav with ...Bf5, a system which I currently play, is this system good against stronger or weaker opponents?
  
  I did some research on ChessBase, and the conclusion is that surprisingly a very large rating gap does not alter the usual frequencies at which openings are played. Which proves that when they face much stronger or much weaker opponents, almost no one tries to exploit the gap in strength by choosing specific openings. E.g. When White is much stronger than Black, White doesn't play 1.e4 2.Qh5 at a much higher frequency than usual.
  
  **Tags:** opening
  
  > **Comments:**
  > **username_1**: Doesn't really answer your question, but three factors that are good to consider at any level: objective strength of an opening, how comfortable you are with it, and how well-versed you anticipate your opponent will be with the theory.  
  > **username_2**: My goal in the opening is to get to a structure I prefer and know the plans and timing well.  
  > **username_3**: Probably almost anything will work against much weaker opponents -- and therefore, almost nothing will against much stronger opponents. They're much weaker / stronger, you'll win / lose almost all the time. Openings don't influence that much.  
  > **username_0**: @username_3: True, regardless of what opening you play, against a much stronger (resp. weaker) player you will almost always lose (resp. win). But having two repertoires would increase your winning probability against much stronger players from 1% to 2% and decrease your losing probability against much weaker players from 2% to 1%. A 1% change would usually be completely insignificant, but here it is not. Whether your winning probability is 50% or 51% makes a difference of only 7 Elo. But whether your winning probability is 1% or 2% makes a huge difference, a 120 Elo difference.  
  > **username_3**: Let's say those numbers are true. I just don't see why it would be a good use of your time to learn two entire repertoires to change the result of 1% of the games the 10% of the time you play against a much weaker or much stronger opponent.  
  > **username_0**: @username_3: How valuable changing the result of a game is heavily depends on the rating difference. Imagine that your next three opponents were one super-GM and two players who have the same rating as you. Would you rather win against the super-GM and lose against the other two, or lose against the super-GM and win against the other two?  
  > **username_0**: @username_3: Imagine two players: the first plays only against opponents who are much stronger (800 Elo) than him and so he wins only 1% of the time, the second plays only against players who have the same rating as him and so he wins 50% of the time. "to change the result of 1% of the games" would be extremely valuable for the first player but not valuable for the second player. "to change the result of 1% of the games" would increase the first player's rating by 120 Elo, but it would only increase the second player's rating by 7 Elo.  
  > **username_0**: "the 10% of the time you play against a much weaker or much stronger opponent" > It could be more than 10%. It could be anything really. I could choose to exclusively play only against much stronger or much weaker players, in which case the percentage would be 100%. Or I could choose to exclusively play only against players who have roughly the same rating as me, in which case the percentage would be 0%. If I meet a random dude IRL and he happens to know how to play chess, statistically he's probably gonna be less than 1200 Elo so he's gonna be much weaker than me.  
  > **username_4**: If White is much stronger than Black, there is even less reason than usual to try something like 1.e4 e5 2.Qh5. The rule is, against a much weaker opponent, play solid positional chess; against a much stronger opponent, the opposite.  
  
  ---
  
  ## 2 answers
  
  ### Answer by username_5 on 2023-05-23. Score: 1
  
  My answer is going to be a bit vague, because I know nothing about your skills and knowledge. It’s basically a riff on the way Aleksander Wojtkiewicz approached playing in open tournaments.
  
  First, you’ll want to be playing towards middlegame positions you are comfortable with playing, regardless of opponent. Which ones those are will be unique to you.
  
  Against weaker players, choose variations that limit your risk, and rely on your own better understanding of chess to carry you to victory. By selecting less double-edged lines you both limit the likelihood you will destroy your own game with a mistake, and increase the likelihood your opponent *will* self-destruct. (After all, the simple reason they’re lower rated is because they’re more likely to blunder than you are. Wear them down and wait for the gift.)
  
  Against stronger players, choose more enterprising lines. In a long, slow game against a higher rated player, the “blunder ratio” will be tilted against you, so you want instead a tense battle where it’s difficult to come back from a mistake. The odds you can win a grind-it-out game against a player with better technique are lower than the odds they’ll make a mistake against you in a knife-edged position, giving you an opening for a win.
  
  These variations can coexist within the same opening, or be from completely different openings. Depends on what you like, what positions you play well.
  
  
  ---
  
  ### Answer by username_6 on 2023-05-22. Score: 1
  
  > Which kinds of openings are good against much stronger opponents?
  
  Openings where you know them the best and are most familiar with the plans arising from the openings.
  
  > Which kinds of openings are good against much weaker opponents?
  
  Openings where you know them the best and are most familiar with the plans arising from the openings.
  
  Look, in any situation the best openings are dependent completely on the individual playing them.
  
  If you deviate from playing the openings you know best (including the plans arising from them) then you are deliberately choosing to play openings which are inferior for you, where you will have a smaller advantage against a weaker player and bigger disadvantage against a stronger player.
  
  Of course, if you are trying to learn a new opening then you have to go through a period where you are deliberately handicapping yourself until you get to know the opening and its plans really well, but that's the price for extending your repertoire.
  
  > **Comments:**
  > **username_0**: If I played openings that I don't know very well, I wouldn't score very well. Yes, that's obviously true. But my idea is to have two opening repertoires, and I would learn and know very well all the openings in my two repertoires.  
  > **username_6**: @username_0 You are missing the point. All your opponents, weak or strong, are unique individuals. They play lots of different openings irrespective of their strength. What works against one weak opponent, because they don't know it, will fail badly against another weak opponent because they play it all the time. Your idea of avoiding openings which could be drawish is also wrong. A few years ago I played the black side of a Slav against a player 350 FIDE rating points higher than me.  He played the "drawish" exchange variation and lost.  
  > **username_0**: Of course all opponents are unique individuals, but what matters here are statistical averages, not individual cases. "Opening X is particularly good against much stronger players" means that, if I pick opening X in my repertoire against much stronger players, statistically, on average, my expected average playing strength against much stronger opponents will be say for example 50 Elo more than usual.  
  > **username_0**: If we look at individual cases: Against a much stronger player who studied opening X extremely deeply, my expected playing strength will be 50 Elo less than usual. Against a much stronger player who never studied opening X, my expected playing strength will be 150 Elo more than usual. But ON AVERAGE, my expected playing strength will be 50 Elo more than usual, which is why opening X is particularly good against much stronger players.  
  
  ---
  
  