I don't know much about Zeller. Is he a solid defender, or yet another Celtics big man that is offense only?
a very good question. below is at least one answer. i got it from this online article ...
http://bleacherreport.com/articles/1953338-breaking-down-tyler-zellers-improvement-for-cleveland-cavaliersDefensive ActivityNo one would go as far to call Zeller a great defender, but he's improving.
The weight gain was a big help, especially with guys like Hibbert, Tyson Chandler, Andre Drummond and Al Jefferson in the East to compete against.
Strength was an issue for Zeller last season, as was quickness. The Cavs run a lot of defensive sets requiring the center to slide out and cut off the opposing point guard on pick-and-roll sideline plays. It's then the center's responsibility to get back to his original man, or open post player, as quickly as possible.
Zeller can still be slow on these, and often gets into foul trouble because of it. His blocked shot/shooting foul rating was just .45 last season (via 82games.com). For comparison, Hibbert's is 1.40 this year.
Zeller has been quicker on his recovery this season, and is doing a better job of blocking shots without fouling. His blocked shot/shooting foul rating is up to .84 in 2013-14. Still a long way from a player like Hibbert, but nevertheless a nice improvement from his rookie year.
Here are some other key defensive stats and ratings showing Zeller's improvement from last season. All stats are on a per-36 minute basis.
DRtg REBS STLS BLKS DRB%
2012-13 110 7.8 0.6 1.2 16.7
2013-14 107 9.7 0.8 1.3 19.5
Zeller's added muscle has made a big difference on the boards.
He's now pulling in nearly 20 percent of all available defensive rebounds, and is up to 9.7 total boards per 36 minutes.
Steals and blocks are slightly improved, and his defensive rating is down three points from a season ago.