LoL Coach Tracks Duo's Menstrual Cycle for Win Rate

Five million views and counting for a spreadsheet about someone's period. That's where the League of Legends community landed this week after coach Tony Chau, known as @SaskioLoL on X, posted a thread claiming he'd been tracking his duo partner's menstrual cycle across 147 ranked games to maximize their win rate.

Chau says his overall win rate with his duo partner, yuulu, sits at 55.1%. When she's on her period, that number drops to 52%. When she's not, it climbs to 57.5%. A roughly five-point swing that he argues is too consistent to dismiss. He also claims her playstyle shifts dramatically: during her period, her "aggression rating" spikes to 8.6 out of 10 based on damage dealt and deaths, which leads him to pick Tristana and match her all-in energy. Off period, he says she drops to a 4.85 aggression rating, plays more calculated, and dies less, so he locks Vayne and they farm into late game.

I don't know whether this is a deeply committed bit or someone who has taken data-driven League coaching to its most absurd logical conclusion. Either way, it's one of the strangest "meta" discussions the game has ever produced. There's no independent verification of any of the numbers; it's all self-reported from Chau's own CRM, which yuulu apparently only recently discovered he'd been keeping on her for months.

The timing is particularly spicy given the community's recent memory of FlyQuest's Bwipo facing backlash for comments about women and competitive gaming during periods. Chau's thread occupies a very different tone, framed as a lighthearted optimization exercise between friends rather than a sweeping claim about women in esports. But the proximity to that controversy is probably part of why this blew up the way it did.

Players on X remain split between treating the thread as an elaborate joke and debating whether hormonal cycles could affect in-game performance. Chau posted his data breakdown and CRM screenshots alongside the thread, which yuulu herself apparently acknowledged after discovering the tracking.