Performance rating is not correct

[JeroenED]

When calculating the performance rating, the returned value is not correct

Expected results

Perf P1:      1810
Perf P2:      2602
Perf P3:      1331

Actual results

Perf P1:      1803
Perf P2:      2203
Perf P3:      1401

Path to disaster

$sws = IOFactory::createReader('Pairtwo-6');
$sws->read('../res/testsws.sws');

echo "Perf P1:      " . $sws->getTournament()->getPlayerById(0)->getPerformance($sws->getTournament()->getPriorityElo(), $sws->getTournament()->getNonRatedElo()) . PHP_EOL;
echo "Perf P2:      " . $sws->getTournament()->getPlayerById(1)->getPerformance($sws->getTournament()->getPriorityElo(), $sws->getTournament()->getNonRatedElo()) . PHP_EOL;
echo "Perf P3:      " . $sws->getTournament()->getPlayerById(2)->getPerformance($sws->getTournament()->getPriorityElo(), $sws->getTournament()->getNonRatedElo()) . PHP_EOL;

Libpairtwo version

ae832bb

PHP version

$ php -v
PHP 7.3.6-1+ubuntu18.04.1+deb.sury.org+1 (cli) (built: May 31 2019 11:06:48) ( NTS )

SWS File

https://github.com/JeroenED/libpairtwo/blob/ae832bb02525e4907a1d3b706c2f21ad3e1f5b15/res/testsws.sws