User blog comment:Lukeatlook/Pyro's Item Overhaul 9 - The Carry Project/@comment-24244491-20141229212510/@comment-4813965-20141230010920

Crit is already managed by a pseudo random number generator. If you have 25% crit chance, the first attack has actually lower chance than 25%, then for every attack that doesn't crit you have increased chance of critting. Once you crit, the chance is reset to below 25%.