Famously, Billy Bean said "his (stuff) doesn't work in the playoffs." This is because top end talent still generally wins championships. The regular season is a slog and you can do very well by always beating the teams you should beat. But in the playoffs when everyone is giving maximum focus and effort, the talent gap is much more important than in the regular season. In basketball, I think of teams like this year's Cavaliers or the Budenholzer era Hawks. These teams won a lot of regular season games, but never felt like a legitimate threat to win the championship.