The Celtics got Tyler Zeller for nothing. Well, almost nothing. It was a cap move for the Cavs who needed to dump his salary to get LeBron James (which has worked out OK for them). Granted, that really shouldn't matter when evaluating a player, but I can't seem to think of everything he gives us as found money.
Tyler was not always consistent and he was not the rim protector that we've needed since forever. But he's been an outstanding addition to the team and should be a solid rotation big man for the near future.
First of all, he's still young and improving.
Zeller had the biggest jump on the team with his PER of 18.9 being +4.1 from his career average. Some will argue that Zeller didn't so much improve as get a greater opportunity in Boston. But if you compare Zeller's stats from his rookie season -- one in which he actually played more minutes in a similar number of starts and appearances for a rebuilding team -- his numbers spiked despite playing five minutes less per game this season. Most notably, Zeller averaged a career-best 10.2 points per game while shooting 54.9 percent from the floor (this after averaging 7.9 points per game while shooting 43.8 percent in his rookie season).
Secondly, he's better defensively than you might think. See this analysis from our own Kevin O'Connor from earlier this year.
Zeller's pick-and-roll defense numbers on Synergy are right around the league average, but that is largely due to the fact Boston drops or "ices" pick-and-rolls, which encourages opponents to shoot threes. However, the Celtics big man is shining according to other metrics. Vantage Sports records a statistic called "Keep-in-Front %," which measures the percentage of drives a defender stays between the opponent and the basket. Zeller ranks 3rd in the NBA with an 84.5 Keep-in-Front %, which supports the assertion that his defensive success is largely due to his sound fundamentals. The league average for all big men is 68.9, according to Vantage Sports, which means Tyler Zeller is elite in this category.
With all these glowing things said about Zeller, I still see his upside as limited to "solid rotation player" who's likely best suited for a bench role. Or perhaps he can be a starter on a team that has elite performers elsewhere in the starting lineup (and a rim protecting backup behind him).
Given the low cost of picking him up, his low salary, and his solid growth, I'm very pleased with having Zeller on the team. Of course, he's also a valuable trade chip if his inclusion is required to make a big move. Everything is on the table this offseason (as it usually is with Ainge).
Obviously I'd like to see Tyler continue to work on his all around game. At times he looked fantastic running at the rim on pick and rolls. He's an ok rebounder but could improve in that area with work. In the past few summers he's worked on adding muscle mass and getting stronger and the more he matures the easier that will be.
Zeller is a rock solid big man and potentially a great piece of the Celtics future. Not bad for a guy that Ainge got for next to nothing.