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Current rating
Every boxer gets a first rating of 0 before his first bout.
After every bout, the ratings of the two boxers involved are changed depending on the bout's official result (KO, TKO, RTD, UD, PTS, NWS, MD, SD, DQ, TD, DRAW).
The value of a result varies between v=1 and v=0.
The clear decision factor varies between cd=1 and cd=0.
KO, TKO, RTD are rewarded with full value v=1, cd=1.
NWS is rewarded with full value v=1 for 12 rounds boxed and more and a lower value related to the number of rounds boxed. Clear decision factor cd=1.
UD, PTS are rewarded with full value v=1 for 12 rounds boxed and more and a lower value related to the number of rounds boxed, clear decision factor cd=1. This is valid, if the score cards are not available.
DRAW is rewarded with value v=0 and cd=0.
MD, SD, DQ, TD are rewarded with half value v=0.5 or a lower value, if the number of rounds boxed is lower than 12 rounds, clear decision factor cd=0.5. This is valid, if the score cards are not available.
If the score cards are available, the value rewarded is in relation to the mean score difference per judge. A mean score difference of 6 points or more per judge is rewarded with relative full value v=1. The maximum value is also in relation to the rounds boxed, with full value v=1 for 12 rounds boxed and more. The clear decision factor is in proportion to rounds boxed and the mean score difference per judge. cd=1 for mean score difference divided by a sixth of rounds boxed greater or equal 1.
All bouts are regarded to have the same weight independent of titles.
The winner gets a certain part of the opponent's points and additionaly a certain part of the rating difference to the opponent's rating. The winner gets 10 additional points, if his opponent's rating is higher than a quarter of his own rating.
For a DRAW the rating of the higher rated boxer is reduced by some part of the point difference; the rating of the lower rated boxer is enhanced by the same amount of points.
The full relative point win is 34.5%.
The part for reduction of ratings difference is between 11.5% for full value and 34.5 % for a draw.
The rating of a boxer is reduced by 25%, if he didn't box an opponent with a rating of at least 25% of his own rating points within 18 months.
The rating of a boxer is reduced by an increasing value of 0% to 50% for every time period of inactivity of 12 to 18 months.
A boxer is regarded to have an home advantage, if he has already fought a minimum of two bouts in the country, where the current bout is taking place. The rating of the a boxer with home advantage is assumed to be at 140% for the calculation of the point wins, his opponent's rating is assumed to be at 70% for the calculation of the point wins.
The ratings are decreased for moving up to higher weight divisions by the square of the reciprocal ratio of the weights limits of the divisions - and they are increased by the same factor for moving down the divisions.
The ratings are equalized between divisions in relation to average points of the boxers ranked #9, #10 and #11 in a division.
Formula
If a boxer with a rating of r_a before the fight defeats a boxer b with a rating of r_b before the fight with result of value v and clear decision factor cl the new ratings r_a_new and r_b_new after a fight are:
r_a_new = r_a + 0.345*v*r_b + 0.345/(1+2*cl)*(r_b - r_a)
r_b_new = r_b - 0.345*v*r_b - 0.345/(1+2*cl)*(r_b - r_a)
Examples
Boxer a KO boxer b, a has 1000 points, b has 500 points. v=1, cl=1.
r_a_new = 1000 + 0.345*1*500 + 0.345/(1+2*1)*(500 - 1000) + 10 = 1125
r_b_new = 500 - 115 = 385
Boxer a KO boxer b, a has 1000 points, b has 500 points. v=1, cl=1. Boxer b has the home advantage.
For the calculation the rating of boxer b is assumed to be 500*1.4 = 700
For the calculation the rating of boxer a is assumed to be 1000*0.7 = 700
r_a_new = 1000 + 0.345*1*700 + 0.345/(1+2*1)*(700 - 700) + 10 = 1252
r_b_new = 500 - 242 = 258
Boxer a UD 6 boxer b, scores 59:55 58:56 58:56, a has 1000 points, b has 500 points.
UD is rewarded with v=1 at maximum
A 6 rounder is rewarded with value 6/12 at maximum v=0.5
mean score difference per judge is (4+2+2)/3 = 2.667, which is rewarded with value 2.667/6 at maximum = 0.445
so v=0.445
close decision factor is in relation to rounds boxed 12/6, so cl=0.89
r_a_new = 1000 + 0.345*0.445*500 + 0.345/(1+2*0.89)*(500 - 1000) +10 = 1025
r_b_new = 500+15= 485
Boxer a SD 4 boxer b, scores 39:37 39:37 37:39, a has 1000 points, b has 500 points
SD is rewarded with v=0.5 at maximum
A 4 rounder SD is rewarded with 0.5/12*4 at maximum v=0.167
mean score difference per judge is (2+2-2)/3 = 0.667, which is rewarded with 0.667/6 at maximum v=0.111
close decision factor is in relation to rounds boxed 12/4, so cl=0.333
r_a_new = 1000 + 0.345*0.111*500 + 0.345/(1+2*0.333)*(500 - 1000) +10 = 926
r_b_new = 500+66 = 566
[edit]All Time Ratings
The All Time Ratings show the average of the best 5 annual ratings in the division assigned by the editors.
http://www.boxrec.com/media/index.ph...gs_Description
Its not really like anyone follows or cares about boxrec's rankings, and arent exactly taken seriouslyat all...but at least these explains somewhat where they get their rankings from.
Some of the calculations they us are weird...but I guess its a good idea...in theory at least.
________
HOME MADE VAPORIZER
Every boxer gets a first rating of 0 before his first bout.
After every bout, the ratings of the two boxers involved are changed depending on the bout's official result (KO, TKO, RTD, UD, PTS, NWS, MD, SD, DQ, TD, DRAW).
The value of a result varies between v=1 and v=0.
The clear decision factor varies between cd=1 and cd=0.
KO, TKO, RTD are rewarded with full value v=1, cd=1.
NWS is rewarded with full value v=1 for 12 rounds boxed and more and a lower value related to the number of rounds boxed. Clear decision factor cd=1.
UD, PTS are rewarded with full value v=1 for 12 rounds boxed and more and a lower value related to the number of rounds boxed, clear decision factor cd=1. This is valid, if the score cards are not available.
DRAW is rewarded with value v=0 and cd=0.
MD, SD, DQ, TD are rewarded with half value v=0.5 or a lower value, if the number of rounds boxed is lower than 12 rounds, clear decision factor cd=0.5. This is valid, if the score cards are not available.
If the score cards are available, the value rewarded is in relation to the mean score difference per judge. A mean score difference of 6 points or more per judge is rewarded with relative full value v=1. The maximum value is also in relation to the rounds boxed, with full value v=1 for 12 rounds boxed and more. The clear decision factor is in proportion to rounds boxed and the mean score difference per judge. cd=1 for mean score difference divided by a sixth of rounds boxed greater or equal 1.
All bouts are regarded to have the same weight independent of titles.
The winner gets a certain part of the opponent's points and additionaly a certain part of the rating difference to the opponent's rating. The winner gets 10 additional points, if his opponent's rating is higher than a quarter of his own rating.
For a DRAW the rating of the higher rated boxer is reduced by some part of the point difference; the rating of the lower rated boxer is enhanced by the same amount of points.
The full relative point win is 34.5%.
The part for reduction of ratings difference is between 11.5% for full value and 34.5 % for a draw.
The rating of a boxer is reduced by 25%, if he didn't box an opponent with a rating of at least 25% of his own rating points within 18 months.
The rating of a boxer is reduced by an increasing value of 0% to 50% for every time period of inactivity of 12 to 18 months.
A boxer is regarded to have an home advantage, if he has already fought a minimum of two bouts in the country, where the current bout is taking place. The rating of the a boxer with home advantage is assumed to be at 140% for the calculation of the point wins, his opponent's rating is assumed to be at 70% for the calculation of the point wins.
The ratings are decreased for moving up to higher weight divisions by the square of the reciprocal ratio of the weights limits of the divisions - and they are increased by the same factor for moving down the divisions.
The ratings are equalized between divisions in relation to average points of the boxers ranked #9, #10 and #11 in a division.
Formula
If a boxer with a rating of r_a before the fight defeats a boxer b with a rating of r_b before the fight with result of value v and clear decision factor cl the new ratings r_a_new and r_b_new after a fight are:
r_a_new = r_a + 0.345*v*r_b + 0.345/(1+2*cl)*(r_b - r_a)
r_b_new = r_b - 0.345*v*r_b - 0.345/(1+2*cl)*(r_b - r_a)
Examples
Boxer a KO boxer b, a has 1000 points, b has 500 points. v=1, cl=1.
r_a_new = 1000 + 0.345*1*500 + 0.345/(1+2*1)*(500 - 1000) + 10 = 1125
r_b_new = 500 - 115 = 385
Boxer a KO boxer b, a has 1000 points, b has 500 points. v=1, cl=1. Boxer b has the home advantage.
For the calculation the rating of boxer b is assumed to be 500*1.4 = 700
For the calculation the rating of boxer a is assumed to be 1000*0.7 = 700
r_a_new = 1000 + 0.345*1*700 + 0.345/(1+2*1)*(700 - 700) + 10 = 1252
r_b_new = 500 - 242 = 258
Boxer a UD 6 boxer b, scores 59:55 58:56 58:56, a has 1000 points, b has 500 points.
UD is rewarded with v=1 at maximum
A 6 rounder is rewarded with value 6/12 at maximum v=0.5
mean score difference per judge is (4+2+2)/3 = 2.667, which is rewarded with value 2.667/6 at maximum = 0.445
so v=0.445
close decision factor is in relation to rounds boxed 12/6, so cl=0.89
r_a_new = 1000 + 0.345*0.445*500 + 0.345/(1+2*0.89)*(500 - 1000) +10 = 1025
r_b_new = 500+15= 485
Boxer a SD 4 boxer b, scores 39:37 39:37 37:39, a has 1000 points, b has 500 points
SD is rewarded with v=0.5 at maximum
A 4 rounder SD is rewarded with 0.5/12*4 at maximum v=0.167
mean score difference per judge is (2+2-2)/3 = 0.667, which is rewarded with 0.667/6 at maximum v=0.111
close decision factor is in relation to rounds boxed 12/4, so cl=0.333
r_a_new = 1000 + 0.345*0.111*500 + 0.345/(1+2*0.333)*(500 - 1000) +10 = 926
r_b_new = 500+66 = 566
[edit]All Time Ratings
The All Time Ratings show the average of the best 5 annual ratings in the division assigned by the editors.
http://www.boxrec.com/media/index.ph...gs_Description
Its not really like anyone follows or cares about boxrec's rankings, and arent exactly taken seriouslyat all...but at least these explains somewhat where they get their rankings from.
Some of the calculations they us are weird...but I guess its a good idea...in theory at least.
________
HOME MADE VAPORIZER
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