rating

mamer rating formula
--------------------

 Pre_tourney stats:
   pre_wins
   pre_draws
   pre_losses
   pre_rating  - this is what we have to initialize

 
 From the tourney just completed:
   tourn_wins, tourn_draws, tourn_losses

 Post tourney stats: stuff that is saved.
   post_wins, post_draws, post_losses, post_rating


 Calculations:
  tourn_expect = sigma(over all rounds) {1/[1+10^(delta/400)]}
         delta = player_FICS_rating - opponent_FICS_rating

    pre_expect = (pre_wins + 0.5*pre_draws)/pre_rating

     post_wins = pre_wins + tourn_wins
    post_draws = pre_draws + tourn_draws
   post_losses = pre_losses + tourn_losses

   post_rating = (post_wins + 0.5*post_draws)/(pre_expect + tourn_expect)


  Comments:
----------------
Ratings will tend to be near 1.0, and a typical range is 0.5 to 1.5.
Ratings are initialized based on your win percentage.

 Questions, comments, suggestions?? contact mlong.

[Last modified: August 19, 1998 -- fpawn & mlong]
