The Boston Celtics finally landed the kind of star they've been trying to acquire: Al Horford. So, after surprising the league by winning 48 games last season, how good is Boston now?
Projecting Boston with Horford
While the Celtics' 2015-16 season might have been unexpected in many quarters, their rise was predicted by ESPN's real plus-minus (RPM). Projections based on the multiyear, predictive version of RPM pegged Boston for precisely 48 wins before the season, the second-best forecast in the Eastern Conference.
While they did win 48, as predicted, the Celtics didn't finish quite that high because the Toronto Raptors dramatically outperformed their RPM projection. Still, the C's did finish tied for third in the East during the regular season. (Tiebreakers pushed the Celtics down to the fifth playoff seed, where they lost to Horford's Hawks without home-court advantage in the first round.)
So now let's take a look at what the preliminary version of those projections says about the 2016-17 Celtics, taking into account their 13 players currently under contract.
RPM sees next season's Celtics as a much more balanced team. In 2015-16, Boston was only league average in offensive rating, but the 2016-17 projection calls for the Celtics to score 1.9 more points per 100 possessions than an average team.
In fact, just three teams were as good relative to average at both ends last season as the Celtics' projection, all of them in the West: the Golden State Warriors, Los Angeles Clippers and San Antonio Spurs.
Overall, RPM pegs Boston for about 53 wins, which would have tied for the league's sixth-best record last season. With the Raptors likely to take a step backward after the best season in franchise history, I'd consider the Celtics the early favorites to finish second in the East behind the Cleveland Cavaliers.
Of course, Horford's greatest value probably won't be evident until the playoffs. After all, depth, defense and execution meant Boston was already a good regular-season team. That didn't translate in the playoffs, when the Celtics couldn't find enough capable two-way options to compete against Atlanta after losing Avery Bradley to injury.
Most notably, Boston's starting frontcourt of Amir Johnson and Jared Sullinger couldn't defend mobile Hawks counterparts Horford and Paul Millsap. Presumably, Horford will take Sullinger's spot in the starting lineup, upgrading the Celtics' shooting and making them more athletic defensively.
Adding Horford is a coup for Boston and a big step forward in the team's long-term plan -- it adds a player who helps now and might attract other players later. And the Celtics have a chance to reach the Eastern Conference finals with or without Durant.