Rating\Rating::_getExpectedScores PHP Метод

    protected function _getExpectedScores($ratingA, $ratingB)
    {
        $expectedScoreA = 1 / (1 + pow(10, ($ratingB - $ratingA) / 400));
        $expectedScoreB = 1 / (1 + pow(10, ($ratingA - $ratingB) / 400));
        return array('a' => $expectedScoreA, 'b' => $expectedScoreB);
    }