#!/usr/bin/perl

# Make a pool of random players with known true ratings between 1000 to 2000
# Set the calculated ratings to be the same as the true ratings
# Play games between randomly selected players with the outcome
#     determined by the true ratings
# Calculate the system error

require "func.pl";

runTests();

sub makePlayers{
  local($i);

  for($i=0;$i<$MaxPlayers;$i++){
    $Tr[$i] = int(rand(1000)) + 1000;
  }
}

sub setCalc2True{
  @Cr = @Tr;
}

sub setCalc2Init{
  local($i);

  for($i=0;$i<$MaxPlayers;$i++){
    $Cr[$i] = 1500;
  }
}

sub updateRatings{
  local($p1, $p2, $w1) = @_;
  local($r1, $r2);

  ($r1) = newRating($Cr[$p1], $Cr[$p2], $w1);
  ($r2) = newRating($Cr[$p2], $Cr[$p1], 1 - $w1);
  $Cr[$p1] = $r1;
  $Cr[$p2] = $r2;
}

sub newRating{
  local($mr, $or, $iwon) = @_;
  local($rdiff, $wp, $k, $nr);

  $rdiff = ($or - $mr)/400;
  $wp = 1.0/(1.0 + 10.0**$rdiff);

  $k = 32;
  $nr = int($mr + $k*($iwon - $wp) + 0.5);
  return $nr;
}