As the Celtics soared up the defensive rankings after a slow start to the season,

everyone around the organization stressed it was Marcus Smart’s impact that was the difference.

The C’s boasted plenty of stalwarts on their way to the top-ranked defensive efficiency in the league,

and those same contributors all said Smart was the most important piece of Boston’s defense.

All the campaigning worked. Smart won the NBA Defensive Player of the Year award Monday, the league announced.

It’s the first time since the 1995-96 season that a guard has won the award,

when Gary Payton was given those honors. “First off, definitely want to thank you guys,

man, my coaching staff and teammates,” Smart said in a video posted by the Celtics on Twitter.

“It’s not easy playing in this league full of guys like Jayson (Tatum) and Jaylen (Brown),

who scores the ball the way they do, and getting the recognition on the defensive end and trying to guard these guys every night.

Marcus Smart named NBA