What was that article named?

I’m recalling a Less Wrong post about how rationality only leads to winning if you “have enough of it”. Like if you’re “90% rational”, you’ll often “lose” to someone who’s only “10% rational”. I can’t find it. Does anyone know what I’m talking about, and if so can you link to it?

I’m not sure if this is appropriate to ask. If not, let me know.