WALTHAM -- After practice Friday afternoon, Boston Celtics assistant coach Jay Larranaga helped guard Marcus Smart with an unorthodox shooting drill. As Smart attempted a series of 3-pointers, Larranaga held his hand on the player's back, making sure Smart wouldn't lean backward during his release.

The initiative (video above) is the latest attempt to tweak Smart's shooting form, which has resulted in career 29.1-percent accuracy from behind the arc.

"It's just to keep my balance, really," Smart said. "Just shooting it through contact and just really staying focused on the shot. We've been doing it for a while."

Smart said he and Larranaga -- who set a number of 3-point records at Bowling Green before a long and successful overseas playing career -- do the drill every day.

"I come, get my shots up, and just really focus on shooting through the contact," Smart said.

In his third season, the rugged competitor has shown real progress in the low post and pick-and-rolls, but still hasn't figured out the art of putting the ball through the basket. The issues deepened after the All-Star break, when he dipped all the way to 23.2-percent 3-point shooting on more than four attempts per game.

Smart has worked on altering pieces of his shot before. During the offseason, he tried to eliminate dropping the ball well below his waste before starting his release. But nothing has stuck. The guard has gone through stretches of shotmaking, but has also suffered through long periods of startling inaccuracy.

"They're not falling, but I'm putting in the work," Smart said. "So it's just a matter of time."