After multiple seasons near the top of the Eastern Conference, Joe Mazzulla’s Boston Celtics faced a potentially devastating reality last offseason. With Jayson Tatum out for an extended period due to a torn Achilles and the team up against the salary cap, there was some thought the Celtics should treat the 2025-26 NBA season as a rebuilding year.

Breaking down Joe Mazzulla’s Coach of the Year win and why his team’s development is more impressive than the high win total.