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Adar Alguetti

USATT#: 83381

Introduction
This page explains how Adar Alguetti (USATT# 83381)'s rating went from 2243 to 2233 at the US Open held on - 6 Jul 2013. These ratings are calculated by the ratings processor which goes through 4 passes over the match results data for a tournament. The following values are produced at the end of each of the 4 passes of the ratings processor for Adar Alguetti for this tournament.

Initial Rating Pass 1 Pass 2 Pass 3 Final Rating (Pass 4)
2243 2222 2243 2243 2232


You can click here to view a table of all the resultant values from each of the 4 passes (and the initial rating) of the ratings processor for all of the 782 players in this tournament. Sections below for further details on the initial rating and the 4 passes of the ratings processor.

Note: We use mathematical notation to express the exact operations carried out in each pass of the ratings processor below. Whenever you see a variable/symbol such as for example Xi3, we are following the convention that the superscript part of the variable (in this case "3") indicates an index (such as in a series), and it should not be misconstrued to be an exponent (which is how it is used by default).

Initial Rating
The initial rating of a player for a tournament is the rating the player received at the end of the most recent tournament prior to the current tournament. If this is the first tournament the player has ever participated in (based on our records), then the player has no initial rating.

The initial rating for US Open held on - 6 Jul 2013 for Adar Alguetti, and its source tournament are as follows:
Initial Rating From Tournament Start Day End Day
2243 Westchester 2013 June Open n/a 23 Jun 2013

Click here to view the details of the initial ratings for all the players in this tournament.

Pass 1 Rating
In Pass 1, we only consider all the players that come into this tournament with an initial rating while ignoring all the unrated players. If a rated player has a match against an unrated player, then that match result is ignored from the pass 1 calculations as well. We apply the point exchange table shown below to all the matches participated in by the rated players:

Point Spread Expected Result Upset Result
0 - 12 8 8
13 - 37 7 10
38 - 62 6 13
63 - 87 5 16
88 - 112 4 20
113 - 137 3 25
138 - 162 2 30
163 - 187 2 35
188 - 212 1 40
213 - 237 1 45
238 and up 0 50

Suppose player A has an initial rating of 2000 and player B has an initial rating of 2064, and they played a match against each other. When computing the impact of this match on their rating, the "Point Spread" (as it is referred to in the table above) between these two players is the absolute value of the difference their initial ratings. When the player with the higher rating wins, presumably the better player won, which is the expected outcome of a match, and therefore the "Expected Result" column applies. If the player with the lower rating wins the match, then presumably this is not expected, and therfore it is deemed as an "Upset Result" and the value from that column in the table above is used. So, in our example of player A vs player B, if player B wins the watch, then the expected outcome happens, and 5 points are added to player B's rating and 5 points are deducted from player A's rating. Looking at Adar Alguetti's match results and applying the point exchange table, gives us the following result:

Adar Alguetti's Wins
Winner Loser
Point Spread Outcome Gain Player USATT # Rating Player USATT # Rating
222 EXPECTED 1 Adar Alguetti 83381 2243 Jia Feng (Jason Chen 78519 2021
489 EXPECTED 0 Adar Alguetti 83381 2243 Evans Chu 88716 1754
283 EXPECTED 0 Adar Alguetti 83381 2243 Zhihan Chu 84580 1960
188 EXPECTED 1 Adar Alguetti 83381 2243 Brandon Gardner 74893 2055
297 EXPECTED 0 Adar Alguetti 83381 2243 Luvena Huo 83419 1946
90 EXPECTED 4 Adar Alguetti 83381 2243 Lester Lee 76963 2153
0 0 Adar Alguetti 83381 0 Jhonathan Lopez Correa 91132 0
196 EXPECTED 1 Adar Alguetti 83381 2243 Wai M. Wong 45824 2047
176 EXPECTED 2 Adar Alguetti 83381 2243 James Yu 88377 2067

Adar Alguetti's Losses
Winner Loser
Point Spread Outcome Loss Player USATT # Rating Player USATT # Rating
0 -0 Xuebo Li 91181 0 Adar Alguetti 83381 0
186 EXPECTED -2 Billy Xu Ding 71687 2429 Adar Alguetti 83381 2243
49 UPSET -13 Dan Robert Seemiller Jr 27825 2194 Adar Alguetti 83381 2243
172 EXPECTED -2 Justin Nguyen 33784 2415 Adar Alguetti 83381 2243
123 EXPECTED -3 Theodore Tran 73757 2366 Adar Alguetti 83381 2243
21 UPSET -10 Maoxi George Wang 75687 2222 Adar Alguetti 83381 2243
0 -0 Nan Wang 90913 0 Adar Alguetti 83381 0

You can click here to view a table of outcomes and points gained/lost from all the matches with all the players in this tournament.

The "Outcome" column above, shows whether the match had an expected (player with the higher rating wins the match) or an upset (player with the higher rating loses the match) outcome. Based on this outcome, and using both the player's initial rating, we apply the point exchange table from above and show the ratings points earned and lost by Adar Alguetti in the "Gain" column. Matches are separated out into two tables for wins and losses where points are gained and lost respectively. We get the following math to calculate the Pass 1 Rating for Adar Alguetti:

Initial Rating Gains/Losses Pass 1 Rating
2243 + 0 - 2 - 13 - 2 - 3 - 10 + 0 + 1 + 0 + 0 + 1 + 0 + 4 + 0 + 1 + 2 =2222

You can click here to view a table of pass1 calculations for all the rated players in this tournament.

Pass 2 Rating
The purpose of this pass is solely to determine ratings for unrated players. To do this, we first look at the ratings for rated players that came out of Pass 1 to determine an “Pass 2 Adjustment”. The logic for this is as follows:

  1. We calculate the points gained in Pass 1. Points gained is simply the difference between the Pass 1 Rating and the Initial Rating of a player:

    ρi2 = Pi1 - Pi0
    where,

    Symbol Universe Description
    Pi0 Pi0+ the initial rating for the i-th player. We use the symbol P and the superscript 0 to represent the idea that we sometimes refer to the process of identifying the initial rating of the given player as Pass 0 of the ratings processor.
    Pi1 Pi1+ the Pass 1 rating for the i-th player.
    ρi2 ρi2 the points gained by the i-th player in this tournament. Note here that we use the superscript 2 to denote that this value is calculated and used in Pass 2 of the ratings processor. Further, ρi2 only exists for players who have a well defined Pass 1 Rating. For Players with an undefined Pass 1 Rating (unrated players), will have an undefined ρi2.
    i i[1,782] the index of the player under consideration. i can be as small as 1 or as large as 782 for this tournament and the i-th player must be a rated player.

  2. For rated players, Pass 1 points gained, ρi2, is used to calculate the Pass 2 Adjustment in the following way:
    1. If a player gained less than 50 points (exclusive) in pass 1, then we set that player's Pass 2 Adjustment to his/her Initial Rating.
    2. If a player gained between 50 and 74 (inclusive) points in pass 1, then we set the player's Pass 2 Adjustment to his/her Final Pass1 Rating.
    3. If a player gains 75 or more points (inclusive) in pass 1, then the following formula applies:
      • If the player has won at least one match, and lost at least 1 match in the tournament, then the player's Pass 2 Adjustment is the average of his/her Final Pass 1 Rating and the average of his/her opponents rating from the best win and the worst loss, represented using the formula below:

        αi2 = Pi1 + Bi + Wi 2 2

        where αi2 is the Pass 2 Adjustment for the current player, Pi1 is the Pass 1 Rating, Bi is the rating of the highest rated opponent against which the current player won a match, and Wi is the rating of the lowest rated opponent against which the current player lost a match.
      • If a player has not lost any of his/her matches in the current tournament, the mathematical median (rounded down to the nearest integer) of all of the player's opponents initial rating is used as his/her Pass 2 Adjustment:

        αi2 = {Pk0}

        where Pk0 is the initial rating of the player who was the i-th player's opponent from the k-th match.
        Symbol Universe Description
        i i[1,782] the index of the player under consideration. i can be as small as 1 or as large as 782 for this tournament and the i-th player must be a rated player.
        q q[1,3646] the index of the match result under consideration. q can be as small as 1 or as large as 3646 for this tournament and the q-th match must be have both rated players as opponents.
        g g[1,5] the g-th game of the current match result under consideration. q can be as small as 1 or as large as 5 for this tournament assuming players play up to 5 games in a match.
        Pk0 Pk0+ initial rating of the i-th player's opponent from the k-th match.


      • Therefore, the Pass 2 Adjustment for Adar Alguetti is calculated as follows:
        • Given the initial rating of 2243,
        • and the Pass 1 rating of 2222,
        • the Pass 1 gain is 2222 - 2243 = -21.
        • Since the Pass 1 gain of -21 is less than 50, the Pass 2 Rating (also referred to as Pass 2 Adjustment) is reset back to the initial rating.
        • Therefore the Pass 2 Adjustment for Adar Alguetti is 2243.

        You can click here to view a table of Pass 2 Adjustments for all the rated players in this tournament.

  3. After calculating the Pass 2 Adjustment for all the rated players as described above, we can now calculate the Pass 2 Rating for all the unrated players in this tournament (which is the main purpose of Pass 2). Pass 2 Rating is calculated using the following formula:
    1. If all of the matches of an unrated player are against other unrated players, then the Pass 2 Rating for that player is simply set to 1200. You can click here to view these players who received a 1200 Pass 2 Rating. Not all of Adar Alguetti's matches were against unrated players. So this rule does not apply to him.
    2. For unrated players with wins and losses, where at least 1 of the opponents has an initial rating, the Pass 2 Rating is the average of the best win and the worst loss (using the Pass 2 Adjustment of all rated players) as defined by this formula here:

      Pi2 = Bi2 + Wi2 2

      where Pi2 is the Pass 2 Rating for the i-th player, Bi2 is the largest Pass 2 Adjustment (best win) of the opponenet against whom the i-th player won a match, and Wi2 is the smallest Pass 2 Adjustment (worst loss) of the opponent against whom the i-th player lost a match.
    3. For unrated players with all wins and no losses, where at least 1 of the opponents has an initial rating, the Pass 2 Rating is calculated using the following formula:
      Pi2 = Bi2 + k=0Mi-1 I(Bi2-αk2)
      where the function I(x) is defined as, \begin{equation} I(x)=\left\{ \begin{array}{ll} 10, & \text{if}\ x >= 1, x <= 50 \\ 5, & \text{if}\ x >= 51, x <=100 \\ 1, & \text{if}\ x >= 101, x <= 150 \\ 0, & \text{otherwise} \end{array}\right. \end{equation}
      where,
      Symbol Universe Description
      Pi2 Pi2+ the pass 2 rating, of the i-th player in this tournament only applicable to unrated players, where Pi0 is not defined
      Bi2 Bi2+ the largest of the Pass 2 Adjustments of opponents of the i-th player against whom he/she won a match.
      αk2 αk2+ the Pass 2 Adjustment of the player who was the opponent of the i-th player in the k-th match
      I(x) I:+ a function that maps all integers to one of the values from -- 0, 1, 5, 10.
      Mi Mi+ total number of matches played by the i-th player in this tournament
      k k[0,Mi-1]+ The index of the match of the i-th player ranging from 0 to Mi-1
    4. For unrated players with all losses and no wins, where at least 1 of the opponents has an initial rating, the Pass 2 Rating is calculated using the following formula:
      Pi2 = Wi2 + k=0Mi-1 I(Wi2-αk2)
      where I(x) is defined above and,

      Symbol Universe Description
      Pi2 Pi2+ the pass 2 rating, of the i-th player in this tournament only applicable to unrated players, where Pi0 is not defined
      Wi2 Wi2+ the smallest of the Pass 2 Adjustments of opponents of the i-th player against whom he/she lost a match.
      αk2 αk2+ the Pass 2 Adjustment of the player who was the opponent of the i-th player in the k-th match
      I(x) I:+ a function that maps all integers to one of the values from -- 0, 1, 5, 10.
      Mi Mi+ total number of matches played by the i-th player in this tournament
      k k[0,Mi-1]+ The index of the match of the i-th player ranging from 0 to Mi-1
    5. For the rated players, all the work done in Pass 1 and Pass 2 to undone and they have their ratings reset back to their initial ratings while the unrated players keep their Pass 2 Adjustment as their final Pass 2 Rating. Since Adar Alguetti is a rated player, his Pass 2 Adjustment of 2243 will be ignored, along with him Pass 1 Rating of 2222 and his Pass 2 Rating will be set to his initial rating of 2243 with which he came into this tournament.


Click here to see detailed information about the Pass 2 Ratings of all the other players in this tournament.

Pass 3 Rating
Any of the unrated players who have all wins or all losses are skipped in Pass 3. Since Adar Alguetti has an initial rating of 2243, he is not an unrated player, and therefore this rule does not apply to him. You can click here to view list of all the players that are skipped in this Pass 3.

Pass 3 Rating is calculated using 2 steps described below:
  1. In the first part of Pass 3, we apply the point exchange table described in Pass 1 above except this time by using all the players' Pass 2 Ratings. Looking at Adar Alguetti's wins and losses and applying the point exchange table, gives us the following result:
    Adar Alguetti's Wins
    Winner Loser
    Point Spread Outcome Gain Player USATT # Rating Player USATT # Rating
    222 EXPECTED 1 Adar Alguetti 83381 2243 Jia Feng (Jason Chen 78519 2021
    489 EXPECTED 0 Adar Alguetti 83381 2243 Evans Chu 88716 1754
    283 EXPECTED 0 Adar Alguetti 83381 2243 Zhihan Chu 84580 1960
    188 EXPECTED 1 Adar Alguetti 83381 2243 Brandon Gardner 74893 2055
    297 EXPECTED 0 Adar Alguetti 83381 2243 Luvena Huo 83419 1946
    90 EXPECTED 4 Adar Alguetti 83381 2243 Lester Lee 76963 2153
    0 0 Adar Alguetti 83381 0 Jhonathan Lopez Correa 91132 0
    196 EXPECTED 1 Adar Alguetti 83381 2243 Wai M. Wong 45824 2047
    176 EXPECTED 2 Adar Alguetti 83381 2243 James Yu 88377 2067

    Adar Alguetti's Losses
    Winner Loser
    Point Spread Outcome Loss Player USATT # Rating Player USATT # Rating
    0 -0 Xuebo Li 91181 0 Adar Alguetti 83381 0
    186 EXPECTED -2 Billy Xu Ding 71687 2429 Adar Alguetti 83381 2243
    49 UPSET -13 Dan Robert Seemiller Jr 27825 2194 Adar Alguetti 83381 2243
    172 EXPECTED -2 Justin Nguyen 33784 2415 Adar Alguetti 83381 2243
    123 EXPECTED -3 Theodore Tran 73757 2366 Adar Alguetti 83381 2243
    21 UPSET -10 Maoxi George Wang 75687 2222 Adar Alguetti 83381 2243
    0 -0 Nan Wang 90913 0 Adar Alguetti 83381 0