[Andreas]

Hmm, can you give example data for which the script does fail?
As I don't seem to understand what it's all about ...

if ($winnerr[rating] > $loserr[rating])
{
$difference = $winnerr[rating] - $loserr[rating];
}
if ($winnerr[rating] < $loserr[rating])
{
$difference = $loserr[rating] - $winnerr[rating];
}
if ($winnerr[rating] == $loserr[rating])
{
$difference = 0;
}

Why not just

PHP Code:

$difference = abs($winnerr[rating] - $loserr[rating]);