Answers.Body: <p>The <a href="http://www.fide.com/component/handbook/?id=172&amp;view=article" rel="nofollow">FIDE Rating Regulations</a> give details of how the system works. You should scroll down to section <strong>8. The working of the FIDE Rating System</strong>
  which describes the mathematical tables and formulae used for calculating ratings.</p>
  
  <p>Note that a fudge factor called the "Development Coefficient" is used in calculating ratings which determines by how much new results affect your existing rating once you have one. </p>
  
  <blockquote>
    <p>K = 40 for a player new to the rating list until he has completed
    events with at least 30 games</p>
    
    <p>K = 20 as long as a player's rating remains under 2400.</p>
    
    <p>K = 10 once a player's published rating has reached 2400 and remains
    at that level subsequently, even if the rating drops below 2400.</p>
    
    <p>K = 40 for all players until their 18th birthday, as long as their
    rating remains under 2300.</p>
  </blockquote>
  
  <p>As a new player you will have a high K which will mean that your rating will change rapidly if you have results which vary widely from your previous results.</p>
  
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Answers.Text: +1. If you "play it well", the rating can grow very rapidly due to the K-factor... For example, there has been a case recently, where a kid (Parviz Gasimov) went from ~1950 to >2500 in a matter of few months/tournaments. https://chess24.com/en/read/news/from-1949-to-2517-in-three-months
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Answers.Text: This question gives the link to the regulations but the different K factors don't have anything to do with a new player's rating after his first tournament.
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Answers.Text: Sorry - but this does not answer my question. What does K mean? I thought I would get an established FIDE rating after 9 games? What is my opponents expected score against me as I have no rating?
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Answers.UserDisplayName: Brian Towers
Answers.Body: <p>If you're unrated, you don't really have an expected score. How can anything be expected when your rating is totally unknown? But the win expectancy table is sometimes used in <em>reverse</em>, to calculate the rating of an unrated player based on the <em>actual</em> score.</p>
  
  <p>There are actually a few different formulas that might be used to determine your initial rating, depending on the type of tournament and your score, according to the <a href="http://www.fide.com/component/handbook/?id=197&amp;view=article" rel="nofollow noreferrer">FIDE Ratings Regulations</a>:</p>
  
  <blockquote>
    <p>8.2 Determining the Rating 'Ru' in a given event of a previously unrated player.  </p>
    
    <p>8.21 If an unrated player scores zero in his first event his score is disregarded.<br>
    First determine the average rating of his competition 'Rc'.  </p>
    
    <p>(a) In a Swiss or Team tournament: this is simply the average rating of his opponents.</p>
    
    <p>(b) The results of both rated and unrated players in a round-robin tournament are taken into account. For unrated players, the average rating of the competition 'Rc' is also the tournament average 'Ra' determined as follows:<br>
    (i) Determine the average rating of the rated players 'Rar'.<br>
    (ii) Determine p for each of the rated players against all their opponents.<br>
    Then determine dp for each of these players.<br>
    Then determine the average of these dp = 'dpa'.<br>
    (iii) 'n' is the number of opponents.<br>
    Ra = Rar - dpa x n/(n+1)</p>
    
    <p>8.22 If he scores 50%, then Ru = Ra</p>
    
    <p>8.23 If he scores more than 50%, then Ru = Ra + 20 for each half point scored over 50%</p>
    
    <p>8.24 If he scores less than 50% in a Swiss or team tournament:  Ru = Ra + dp   </p>
    
    <p>8.25 If he scores less than 50% in a round-robin: Ru = Ra + dp x n/(n+1)</p>
  </blockquote>
  
  <p>Let's say you play in a Swiss and lose to a 2000, beat an 1800, draw to a 1900, draw a 1750, and lose to a 1950.</p>
  
  <p>The first step is to calculate the average rating of your opponents. In this example, it is 1880. Since you scored less than 50%, we then calculate dp using table 8.1a (which is at the link.) You scored 2/5, which is 40% or 0.4. According to the table, this gives a dp of -72. So your rating for this tournament would be 1880 - 72 = 1808.</p>
  
  <p>When your opponents are calculating their own ratings, this applies:</p>
  
  <blockquote>
    <p>8.52  If the opponent is unrated, then the rating is determined at the end of the event. This applies only to round-robin tournaments. In other tournaments games against unrated opponents are not rated.</p>
  </blockquote>
  
  <p>So your games against them would not count towards their ratings, in this case. But if this was a round-robin instead, then your rating would be calculated first (using the slightly more complicated process for round-robins described above), and their win expectancy against you would then be determined based on your new rating.</p>
  
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Body: <p>Going to play my first international tournament next week.</p>
  
  <p>As this is my first I do not have a FIDE ELO (I have national rating however). </p>
  
  <p>How will my games be rated and how is my expected score for each game calculated?</p>
  
Tags: <rating><tournament><elo><fide>
Title: Expected score in my first FIDE tournament
ThreadText: # Expected score in my first FIDE tournament
  
  (Asked by: username_0 on 2015-03-19)
  
  Going to play my first international tournament next week.
  
  As this is my first I do not have a FIDE ELO (I have national rating however).
  
  How will my games be rated and how is my expected score for each game calculated?
  
  **Tags:** rating, tournament, elo, fide
  
  
  ---
  
  ## 2 answers
  
  ### Answer by username_1 on 2015-03-20. Score: 4
  
  The [FIDE Rating Regulations](http://www.fide.com/component/handbook/?id=172&view=article) give details of how the system works. You should scroll down to section **8. The working of the FIDE Rating System**
  which describes the mathematical tables and formulae used for calculating ratings.
  
  Note that a fudge factor called the "Development Coefficient" is used in calculating ratings which determines by how much new results affect your existing rating once you have one.
  
  > K = 40 for a player new to the rating list until he has completed
  > events with at least 30 games
  >
  > K = 20 as long as a player's rating remains under 2400.
  >
  > K = 10 once a player's published rating has reached 2400 and remains
  > at that level subsequently, even if the rating drops below 2400.
  >
  > K = 40 for all players until their 18th birthday, as long as their
  > rating remains under 2300.
  
  As a new player you will have a high K which will mean that your rating will change rapidly if you have results which vary widely from your previous results.
  
  > **Comments:**
  > **username_2**: +1. If you "play it well", the rating can grow very rapidly due to the K-factor... For example, there has been a case recently, where a kid (Parviz Gasimov) went from ~1950 to >2500 in a matter of few months/tournaments. https://chess24.com/en/read/news/from-1949-to-2517-in-three-months  
  > **username_3**: This question gives the link to the regulations but the different K factors don't have anything to do with a new player's rating after his first tournament.  
  > **username_0**: Sorry - but this does not answer my question. What does K mean? I thought I would get an established FIDE rating after 9 games? What is my opponents expected score against me as I have no rating?  
  
  ---
  
  ### Answer by username_4 on 2019-01-13. Score: 2
  
  If you're unrated, you don't really have an expected score. How can anything be expected when your rating is totally unknown? But the win expectancy table is sometimes used in *reverse*, to calculate the rating of an unrated player based on the *actual* score.
  
  There are actually a few different formulas that might be used to determine your initial rating, depending on the type of tournament and your score, according to the [FIDE Ratings Regulations](http://www.fide.com/component/handbook/?id=197&view=article):
  
  > 8.2 Determining the Rating 'Ru' in a given event of a previously unrated player.
  >
  > 8.21 If an unrated player scores zero in his first event his score is disregarded.  
  > First determine the average rating of his competition 'Rc'.
  >
  > (a) In a Swiss or Team tournament: this is simply the average rating of his opponents.
  >
  > (b) The results of both rated and unrated players in a round-robin tournament are taken into account. For unrated players, the average rating of the competition 'Rc' is also the tournament average 'Ra' determined as follows:  
  > (i) Determine the average rating of the rated players 'Rar'.  
  > (ii) Determine p for each of the rated players against all their opponents.  
  > Then determine dp for each of these players.  
  > Then determine the average of these dp = 'dpa'.  
  > (iii) 'n' is the number of opponents.  
  > Ra = Rar - dpa x n/(n+1)
  >
  > 8.22 If he scores 50%, then Ru = Ra
  >
  > 8.23 If he scores more than 50%, then Ru = Ra + 20 for each half point scored over 50%
  >
  > 8.24 If he scores less than 50% in a Swiss or team tournament: Ru = Ra + dp
  >
  > 8.25 If he scores less than 50% in a round-robin: Ru = Ra + dp x n/(n+1)
  
  Let's say you play in a Swiss and lose to a 2000, beat an 1800, draw to a 1900, draw a 1750, and lose to a 1950.
  
  The first step is to calculate the average rating of your opponents. In this example, it is 1880. Since you scored less than 50%, we then calculate dp using table 8.1a (which is at the link.) You scored 2/5, which is 40% or 0.4. According to the table, this gives a dp of -72. So your rating for this tournament would be 1880 - 72 = 1808.
  
  When your opponents are calculating their own ratings, this applies:
  
  > 8.52 If the opponent is unrated, then the rating is determined at the end of the event. This applies only to round-robin tournaments. In other tournaments games against unrated opponents are not rated.
  
  So your games against them would not count towards their ratings, in this case. But if this was a round-robin instead, then your rating would be calculated first (using the slightly more complicated process for round-robins described above), and their win expectancy against you would then be determined based on your new rating.
  
  
  ---
  
  