However, that same system has seen the third-year head coach secure a 74% regular season win ratio, winning 182 of the 246 games he's led the team. Mazzulla's Celtics are also 33-17 in the postseason.

Mazzulla now holds a combined coaching record of 215-81 across the regular season and playoffs. His breakout came in 2024-25 when he became the youngest coach since 1970 to win an NBA championship.