##Disclaimer

My question **isn't** about how often the FIDE ratings are updated. I know that's done once a month.

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Are ratings adjusted match after match, or after every tournament? Even if the ratings are updated once a month, does FIDE count every match, or a whole tournament?

##An example to make my point clear

Consider a three-player, single round robin tournament.

**Player**                  **Elo**

Roanin Novel          2798

Rigi Hains                2745

Dan H. Yvasin            2784

#Results

**Round 1:** R. Novel (1) beat Rigi Hains (0)

**Round 2:** Rigi Hains (0.5) drew with D.H. Yvasin (0.5)

**Round 3:** D.H. Yvasin (1) drew with R. Novel (1.5)

##My question

If FIDE was calculating the players' ratings, would it first update the players' ratings **match by match**<sup>1</sup>, or would their rating be adjusted by **counting the tournament as a whole?**<sup>2</sup>

<sup>1</sup> In this case, rating changes after every match.

<sup>2</sup> Here we calculate the expected score of each player at the start of the tournament, and compare it with the **final score only.** No rating changes occur between matches.

##The calculations (all assume K=10)

###Method 1 [Match by match] (Final ratings in bold)

 
 
 - After the first match, R. Novel is rated *2802.24* and Rigi is rated *2740.76.*
 
 
 - After the second match, Rigi is rated **2741.38** and Dan is rated *2783.38*
 
 - After the last match, Dan is rated **2783.65** and Novel is rated **2801.97**

###Method 2 [Whole tournament]

1. Roanin Novel
 
 
 
 
  - Initial expected score = 1.096 
 
 
  - Actual score = 1.5
 
  - Hence, new rating = **2802.04**

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2. Rigi Hains 
 
 
 
 
  - Initial expected score = 0.868
 
 
  - Actual score = 0.5
 
  - Hence, new rating = **2741.32**

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3. Dan H. Yvasin
 
 
 
 
  - Initial expected score = 1.036
 
 
  - Actual score = 1.0
 
  - Hence, new rating = **2783.64**

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###Conclusion

 - In such a short tournament, there doesn't seem to be a significant difference in the results of the two methods, but maybe there **could be one in a longer tournament**.

 - Which of them does FIDE use?


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##Note

 
 - If something is unclear, please ask in the comments.