PHP ELO Calculator

[shmeeg]

There's one that I've found...but I'm just struggling applying it to what I'm doing.

 

The idea is to have x number of teams, all starting with 1000 Ranking points. If team A plays team B and wins 1-0, team A should increase by 30 points, and team B should decrease by 30 points? (I think.. )

Then to rank the teams based on their points.

 

The main problem is, I'd like to use a form to edit the teams. I've got as far as a drop down menu to choose the teams, and then Home goals and Away goals. It will already define what is a win/draw/loss.

 

The Calculator code is:

<?php
class elo_calculator
{ public function rating($S1,$S2,$R1,$R2)
  { if (empty($S1) OR empty($S2) OR empty($R1) OR empty($R2)) return null;
    if ($S1!=$S2) { if ($S1>$S2) { $E=120-round(1/(1+pow(10,(($R2-$R1)/400)))*120); $R['R3']=$R1+$E; $R['R4']=$R2-$E; }
                            else { $E=120-round(1/(1+pow(10,(($R1-$R2)/400)))*120); $R['R3']=$R1-$E; $R['R4']=$R2+$E; }}
             else { if ($R1==$R2) { $R['R3']=$R1; $R['R4']=$R2; }
                             else { if($R1>$R2) { $E=(120-round(1/(1+pow(10,(($R1-$R2)/400)))*120))-(120-round(1/(1+pow(10,(($R2-$R1)/400)))*120)); $R['R3']=$R1-$E; $R['R4']=$R2+$E; }
                                           else { $E=(120-round(1/(1+pow(10,(($R2-$R1)/400)))*120))-(120-round(1/(1+pow(10,(($R1-$R2)/400)))*120)); $R['R3']=$R1+$E; $R['R4']=$R2-$E; }}}
    $R['S1']=$S1; $R['S2']=$S2; $R['R1']=$R1; $R['R2']=$R2;
    $R['P1']=((($R['R3']-$R['R1'])>0)?"+".($R['R3']-$R['R1'])$R['R3']-$R['R1']));
    $R['P2']=((($R['R4']-$R['R2'])>0)?"+".($R['R4']-$R['R2'])$R['R4']-$R['R2']));
    return $R; }}
?>