The addition of Aron Baynes has been an important one for the Boston Celtics. As we've discussed before, the man dubbed "All of Australia" represents a true center for a Celtics team lacking in size.

It's not just on the boards or on defense where Baynes' physical prowess matters. It's a key tool in one of the game's simplest plays: the pick and roll.

Baynes has found success as a screener for the Celtics in a few key ways. This starts with his build.

A sturdy screen

Setting a firm pick may be a dying art in the NBA. The last great screen and roll big, Kevin Garnett, was more likely to set an illegal pick than he was to plant his feet and build a wall. Baynes doesn't seem to have this problem.

Here we see where Baynes' size comes into play. Like Steven Adams of the Oklahoma City Thunder, he sets his feet and sets a wide base. In some instances this creates a difficult obstacle for a defender. In other cases, Baynes becomes nearly impenetrable.

Kyrie Irving got a ton of space to get his shot off, literally because his defender could not get around Baynes.

Here's another possession where Larkin is freed from Michael Carter-Williams' pesky defence, and dives in for a drive to the basket, courtesy of a nasty Baynes screen.

https://www.youtube.com/watch?t=1m15s&v=SlsaCYKzDiE&=&app=desktop

A classic pick and roll

It would be good enough if Baynes could come in and simply plant a few defenders now and again. After all, he does play alongside Kyrie Irving, who usually needs but a few centimeters of space to find his shot. Happily for the Celtics, however, Baynes has proven himself a competent roll man.

This starts with a hard screen from Baynes to set up the pick and roll. His own defender often has to step up to try and limit Irving from getting going. A rolling Baynes is then left with a clean path to the basket.

Here it is in action:

https://twitter.com/NBA_AU/status/949791472315908097

Baynes slips screens with equal facility, and gets rewarded for it on the hard roll.

https://twitter.com/AllTheBucks/status/938049539608543233

Baynes is averaging 5.9 points in 18.5 minutes per game thus far, but only 3.6 points are coming in the paint. He's not a prolific free throw shooter, so where are these points coming from?

That good old fashioned mid-range jumper.

That's where Baynes' pick and roll skills really come into play. He's a quality shooter, and can just as easily pop out for a jumper as he can flash to the rim. Take the above example. Zeller is caught in no-man's land, unable to completely abandon Irving in the open court. Carrol is still recovering from the initial screen. No one is accounting for Baynes, who can roll to the rim if he sees an opening or just as easy set himself for a jump shot.

It all started with a good hard screen. This effectively frees up the ball handler, and keeps defenses guessing as to how to handle Baynes.

https://twitter.com/PUSJT/status/949458932556165121

Getting the whole team involved

A solid pick and roll can be an effective, easy play to run at pretty much any stage of an NBA game. Baynes' knack for a reliable screen serves to reinforce this reliability.

The entire motion upends an opposing defense, and with off-ball screens and timely cuts, Irving can instead find an open Horford or Tatum. Baynes himself has shown an ability to pass from the paint, taking advantage of the same proactive offensive approach.

So now, we have a third option for Baynes in the pick and roll. He can set a hard screen, and roll to the rim as an opponent recovers. Likewise, he can linger, setting himself up for a smooth jumper. Or, he can take an extra step and swing the ball to one of his teammates.

None of this works if Baynes can't execute an effective pick and roll, or pick and pop. When it works, both primary defenders are left holding their own, and can't provide help for backdoor cuts or cross-court passes.

Last season, Irving's best pick and roll partner was Cleveland's Tristan Thompson. It was more of a traditional set-up, as TT doesn't poses the same passing skills or mid-range jumper that Baynes has.

Last season in Detroit, meanwhile, Baynes' potential pick and roll partners weren't quite as talented as Irving. He too has benefited from this new pairing, though an effective Baynes screen can happen with or without an All Star ball handler.

A threat to Baynes

What Kyrie and Aron have going on is effective and dependable. But unfortunately for Baynes, there's the possibility that his spot in this foundational play could be usurped.

Just a few months into his NBA career, 25-year old rookie big man Daniel Theis has worked to keep Baynes honest. The German is a bit faster than Baynes, and can stretch the floor with the three ball. In theory, his ability to run either the pick and roll or the pick and pop has a higher ceiling.

What Baynes has over Theis is know-how, and physicality. He still seems a bit better at reading opposing defenses than Theis, who is prone to the occasional rookie mistake. This holds true on the defensive end as well. So long as Baynes can maintain good chemistry with Irving and continue to make smart plays, he'll have a slight inside edge on Theis. This cerebral play can help compensate for a slower first step or limited range shooting the ball.

For now, Baynes' offensive presence is an important one. Not only does it maximize Al Horford by letting him play the four, but it also gives Boston a simple but versatile offensive starting point. It's seldom been pointed out, but Aron Baynes has definitely been one of the undersold acquisitions this summer by the Celtics, and for good reason.