Answers.Body: <p>According to the <a href="https://en.wikipedia.org/wiki/List_of_world_records_in_chess#Highest_percentage_of_draws_in_a_tournament" rel="noreferrer">Wikipedia page of chess world records</a>, the record for draw percentage is 93.3 (that tournament had ten players), meaning no: there hasn't been a recorded tournament with 100% draws.</p>
  
Answers.ContentLicense: CC BY-SA 4.0
Answers.CreationDate: 2021-07-08T13:30:58.147Z
Answers.LastActivityDate: 2021-07-08T13:30:58.147Z
Answers.UserDisplayName: L. Scott Johnson
Body: <p>Do you know a chess tournament (I wrote Round Robin, since it seems extremely improbable for Swiss) where all games ended drawn? Since of course even I can come up from personal experience with a four player tournament where this happened, let's assume at least 8 players. Calculating with a fairly valid drawing probability of 1/2, I get 1/2^(8*7/2)~10^-9, so this would be a very rare event.</p>
  
Comments.ContentLicense: CC BY-SA 4.0
Comments.CreationDate: 2021-07-07T10:03:29.977Z
Comments.Text: Those four guys must be pretty fun to play with...
Comments.UserDisplayName: David
Comments.ContentLicense: CC BY-SA 4.0
Comments.CreationDate: 2021-07-07T13:31:09.163Z
Comments.Text: The record for draw percentage is 93.3 (that tournament had ten players), meaning no: there hasn't been a recorded tournament with 100% draws. https://en.wikipedia.org/wiki/List_of_world_records_in_chess#Highest_percentage_of_draws_in_a_tournament
Comments.UserDisplayName: L. Scott Johnson
Comments.ContentLicense: CC BY-SA 4.0
Comments.CreationDate: 2021-07-07T14:36:45.183Z
Comments.Text: If that happens it's decided on penalty kicks.
Comments.UserDisplayName: DJClayworth
Comments.ContentLicense: CC BY-SA 4.0
Comments.CreationDate: 2021-07-08T07:34:06.630Z
Comments.Text: @L.ScottJohnson: Can you upgrade that to an answer? I didn't know that there was a chess record page on Wiki!! BTW, that result has p=10^-24...(Note that the page probably only records from some certain ELO level upwards, so I won't exclude it has happened at the Hicksville town championship...)
Comments.UserDisplayName: Hauke Reddmann
Comments.ContentLicense: CC BY-SA 4.0
Comments.CreationDate: 2021-07-09T12:38:36.993Z
Comments.Text: @HaukeReddmann with a draw probability of 50%, I calculate drawing 42 of 45 games has p~=10^-10. `C(45,42) * 0.5^42 * (1 - 0.5)^(45-42) = 4.033e-10` . (For "42 or more") the odds go up slightly: 4.328e-10)
Comments.UserDisplayName: L. Scott Johnson
Comments.ContentLicense: CC BY-SA 4.0
Comments.CreationDate: 2021-07-09T15:35:57.393Z
Comments.Text: @L.ScottJohnson: Ah, wrong bracketing on the Google calculator :-) You are correct. Next time I use MATHEMATICA...
Comments.UserDisplayName: Hauke Reddmann
Tags: <draw>
Title: All draw Round Robin
ThreadText: # All draw Round Robin
  
  (Asked by: username_0 on 2021-07-07)
  
  Do you know a chess tournament (I wrote Round Robin, since it seems extremely improbable for Swiss) where all games ended drawn? Since of course even I can come up from personal experience with a four player tournament where this happened, let's assume at least 8 players. Calculating with a fairly valid drawing probability of 1/2, I get 1/2^(8\*7/2)~10^-9, so this would be a very rare event.
  
  **Tags:** draw
  
  > **Comments:**
  > **username_1**: Those four guys must be pretty fun to play with...  
  > **username_2**: The record for draw percentage is 93.3 (that tournament had ten players), meaning no: there hasn't been a recorded tournament with 100% draws. https://en.wikipedia.org/wiki/List_of_world_records_in_chess#Highest_percentage_of_draws_in_a_tournament  
  > **username_3**: If that happens it's decided on penalty kicks.  
  > **username_0**: @username_2: Can you upgrade that to an answer? I didn't know that there was a chess record page on Wiki!! BTW, that result has p=10^-24...(Note that the page probably only records from some certain ELO level upwards, so I won't exclude it has happened at the Hicksville town championship...)  
  > **username_2**: @username_0 with a draw probability of 50%, I calculate drawing 42 of 45 games has p~=10^-10. `C(45,42) * 0.5^42 * (1 - 0.5)^(45-42) = 4.033e-10` . (For "42 or more") the odds go up slightly: 4.328e-10)  
  > **username_0**: @username_2: Ah, wrong bracketing on the Google calculator :-) You are correct. Next time I use MATHEMATICA...  
  
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  ## 1 answers
  
  ### Answer by username_2 on 2021-07-08. Score: 5 | Accepted answer
  
  According to the [Wikipedia page of chess world records](https://en.wikipedia.org/wiki/List_of_world_records_in_chess#Highest_percentage_of_draws_in_a_tournament), the record for draw percentage is 93.3 (that tournament had ten players), meaning no: there hasn't been a recorded tournament with 100% draws.
  
  
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