This is an implementation of the Elo system created by Arpad Elo
Too create a match you can use the MatchFactory class. The code below will create match between players both with an elo of 1500.
$match = MatchFactory::createFromElo(1500, 1500);To get the prediction of who is most likely to win the match. You can use the code below, this will return an percentage
$expectedResult = $match->calculateExpectedResult();