LEADER BOARD

FIBS Rating Formula*

 

These are the formulas used to determine the ratings of a player:

 

Let's say that two players P1 and P2 were playing a n-point match. The ratings of the players are r1 for P1 and r2 for P2 .

 

Let D = abs(r1-r2) (rating difference)

Let P_upset = 1/(10^(D*sqrt(n)/2000)+1) (probability that underdog wins).

Let P=1-P_upset if the underdog wins and P=P_upset if the favorite wins.

 

For the winner:

Let K = max ( 1 , -experience/400+2 )

The rating change is: 4*K*sqrt(n)*P

 

For the loser:

Let K = max ( 1 , -experience/400+2 )

The rating change is: -4*K*sqrt(n)*P

 

The 'experience' of a player is the sum of the lengths of all matches a player has finished. Every player starts with a rating of 1500 and an experience of 0.

 

*Thanks to FIBS (First Internet Backgammon Server) for providing the rating formula as part of their HELP menu.

 

Player Experience ELO Rating Annual Points Race
Al Cantito 759 1706.61 20.5
Bill Porter 255 1595.38 16
Jerry Shea 387 1474.19 14.75
Tom Meyer 746 1702.37 9.25
Andy Fazekas 172 1553.34 4
Sarah Saltus 69 1496.45 3
Ed Corey 621 1446.09 3
Sandy Sisti 647 1376.96 3
Gerhard Roland 273 1498.49 2
Jim Sisti 651 1495.96 1
Adrian Costa 158 1441.59 1
       

Updated 1/19/18

Annual Points Race Accrual Methodology

 

For each tournament event, Points are awarded to players as follows:

 

1.  A player receives 1 Point for each match they win and for every meetup they attend.

 

2.  Bonus Points are established based on the number of event participants and distributed thus:

 

A.  1st Place receives an amount equal to the total number of participants

 

B.  2nd Place receives an amount equal to one-half the total number of participants

 

C.  3rd Place (Optional) receives an amount equal to one-quarter the total number of participants

 

All tournament event points awarded to a player are added to their annual cumulative total.