Al Horford can replace Evan Turner as a secondary playmaker for the Celtics

After years of failing to cash in on their cap space, Danny Ainge and the Boston Celtics got their star free agent. By claiming the opportunity to pay Al Horford $113 million, Boston now has the centerpiece for a smart offense and the rim protector for its fourth-ranked defense. But the biggest move of the offseason might be the one the Celtics didn’t make — by allowing Evan Turner to join the Portland Trailblazers, the team has now effectively made a bet that the glut of guards they’ve accumulated can handle a play-making load larger than any they’ve shouldered under Brad Stevens.

Per NBA.com, Turner ranked just below the top tier of NBA wings in touches per game at 55.8. He was the second-ranked Celtic on this list, behind Isaiah Thomas, who was forced into high-usage grossness far too often last season. What this number brings to light is that even within a ping-ponging offense that plays to the strengths of its components, Turner’s ball-handling was often the focal point of a Celtics possession.

Games like those against the Atlanta Hawks in the playoffs highlight why that strategy is ultimately breakable against elite defenses and elite game plans, but the fact remains that those nearly 60 touches and 30 minutes per game have to go somewhere. Considering that Gerald Green was the only addition Boston made on the wing this summer, that responsibility will fall largely on the guys already on the team.

Thomas and his 30 percent usage rate can’t really be any bigger a piece of this puzzle, and Avery Bradley has found a comfortable niche shooting off the bounce and moving around screens after trying to do too much with the ball early in his career.

Marcus Smart is the most intriguing piece here, of course, after posting low usage possession numbers last season despite increased minutes. He rated near big men and role players in Nylon Calculus’ plays per game statistic, and that matches the role he was asked to play. Stevens used him as something of a Designated Hitter, shredding opposing offenses and igniting transition looks when possible.

Stevens gave his thoughts on Smart’s development to the Ringer last week: “He’s been better off the pick and roll in Year Two, I thought he did a great job of getting into the paint; finishing, kicking out, making plays, especially during the playoffs”. In typical Stevens fashion, he gave us nothing to work with. Smart has definitely improved at reading defenses over two NBA seasons, but he hasn’t shown enough for us to believe he’s ready to be even a secondary ball-handler yet.

In Vegas this summer, we saw Terry Rozier’s Summer League graduation, which is a cause for excitement — his athleticism and savvy consistently overwhelmed the squad-A guys that get thrown out there to fill rosters. He seems ready for more of a burden, but after only 300 NBA minutes, he’s a complete unknown.

Which brings us back to Horford. In Atlanta, the brand of offense that made his Hawks teams yearly playoff locks was contingent upon ball movement and intelligent decision-making. Horford was the rock that held those teams steady; he was the reason Paul Millsap outgrew him as the team’s best player, and a contributor to the positive end of the high-variance Jeff Teague experience. The Other Big Al added a different kind of gravity to the Hawks’ humming machine, the threat of his basketball IQ discombobulating aggressive defense and swarming athleticism.

Horford ranked above Turner in total plays involved, a product of the system that Horford helped build in Atlanta. His peers on that list are bad-team phenoms like Karl-Anthony Towns and D’Angelo Russell. The ball moves whenever Horford is on the court, and when it gets to him, he kicks it where it needs to go.

Horford’s assist rate has hovered just below 20 percent over the past four seasons, and his turnover rate has plummeted in accordance. His decision-making has improved even though the overall talent of his teammates has perhaps diminished. On this year’s Celtics team, next to athletes and shooters like Isaiah and Smart, the opportunities to make his teammates better will be plenty. Horford has shown he’ll be there to answer the call.

Minus the greatly-improved and quietly important Turner, the Celtics seem content to add “offensive playmaker” to the list of hats Horford must wear to bring them closer to contendership this season.