Answers.Body: <p>Basically correct. (Note that these rating systems don't natively deal with draws, only with binary wins/losses. Draws are incorporated by summarizing results as point-score = wins + 0.5 * draws.)</p>
  
Answers.ContentLicense: CC BY-SA 4.0
Answers.CreationDate: 2021-12-21T11:59:39.670Z
Answers.LastActivityDate: 2021-12-21T11:59:39.670Z
Answers.UserDisplayName: Mobeus Zoom
Body: <p>From <a href="https://lichess.org/page/rating-systems" rel="nofollow noreferrer">Lichess page 'Chess rating systems'</a>:</p>
  <p>Question:</p>
  <blockquote>
  <p>Which rating system is best?</p>
  </blockquote>
  <p>Answer:</p>
  <blockquote>
  <p>The purpose of rating systems is to predict the outcome of games. Therefore, they can be objectively better or worse, according to their ability to make such predictions. Glicko 1 makes better predictions than Elo, and Glicko 2 makes better predictions than Glicko 1</p>
  </blockquote>
  <p>My question: <strong>Is 'predict the outcome of games' the same thing as 'reduce the number of upsets' ?</strong></p>
  <p>Upset here is simply lower rating defeating (or drawing against?) higher rating. Thus, assuming all ratings are integer valued and no 2 players of equal rating play against each other, what I understand is that</p>
  <p>'1800 is more likely (or at least as likely) to beat a 1700 if the ratings are glicko 2 as compared to glicko 1'</p>
  <p>if and only if</p>
  <p>'Glicko 2 makes better predictions than Glicko 1'</p>
  <p><strong>Is there anything I misunderstood?</strong></p>
  
Comments.ContentLicense: CC BY-SA 4.0
Comments.CreationDate: 2021-11-20T00:53:55.213Z
Comments.Text: Basically correct. (Note that these rating systems don't natively deal with draws.)
Comments.UserDisplayName: Mobeus Zoom
Comments.ContentLicense: CC BY-SA 4.0
Comments.CreationDate: 2021-11-20T01:00:00.533Z
Comments.Text: @MobeusZoom thanks! what's up with the draws please? (or do i have to make another question for this part?)
Comments.UserDisplayName: BCLC
Comments.ContentLicense: CC BY-SA 4.0
Comments.CreationDate: 2021-12-20T17:04:26.250Z
Comments.Text: @MobeusZoom you can post as answer even if incomplete. i'll award bounty but i guess just not accept bounty. looks like no one's really answering anyway
Comments.UserDisplayName: BCLC
Comments.ContentLicense: CC BY-SA 4.0
Comments.CreationDate: 2021-12-21T11:59:59.997Z
Comments.Text: ok. Not sure it *is* incomplete. You asked if your understanding is right, and it is
Comments.UserDisplayName: Mobeus Zoom
Tags: <rating><statistics><elo><mathematics><glicko>
Title: Rating system (glicko, elo, etc): is 'predict the outcome of games' the same thing as 'reduce the number of upsets'?
ThreadText: # Rating system (glicko, elo, etc): is 'predict the outcome of games' the same thing as 'reduce the number of upsets'?
  
  (Asked by: username_0 on 2021-11-20)
  
  From [Lichess page 'Chess rating systems'](https://lichess.org/page/rating-systems):
  
  Question:
  
  > Which rating system is best?
  
  Answer:
  
  > The purpose of rating systems is to predict the outcome of games. Therefore, they can be objectively better or worse, according to their ability to make such predictions. Glicko 1 makes better predictions than Elo, and Glicko 2 makes better predictions than Glicko 1
  
  My question: **Is 'predict the outcome of games' the same thing as 'reduce the number of upsets' ?**
  
  Upset here is simply lower rating defeating (or drawing against?) higher rating. Thus, assuming all ratings are integer valued and no 2 players of equal rating play against each other, what I understand is that
  
  '1800 is more likely (or at least as likely) to beat a 1700 if the ratings are glicko 2 as compared to glicko 1'
  
  if and only if
  
  'Glicko 2 makes better predictions than Glicko 1'
  
  **Is there anything I misunderstood?**
  
  **Tags:** rating, statistics, elo, mathematics, glicko
  
  > **Comments:**
  > **username_1**: Basically correct. (Note that these rating systems don't natively deal with draws.)  
  > **username_0**: @MobeusZoom thanks! what's up with the draws please? (or do i have to make another question for this part?)  
  > **username_0**: @MobeusZoom you can post as answer even if incomplete. i'll award bounty but i guess just not accept bounty. looks like no one's really answering anyway  
  > **username_1**: ok. Not sure it *is* incomplete. You asked if your understanding is right, and it is  
  
  ---
  
  ## 1 answers
  
  ### Answer by username_1 on 2021-12-21. Score: 1 | Accepted answer
  
  Basically correct. (Note that these rating systems don't natively deal with draws, only with binary wins/losses. Draws are incorporated by summarizing results as point-score = wins + 0.5 \* draws.)
  
  
  ---
  
  