A Complete Lack Of Size

According to FiveThirtyEight.com, the Celtics were the shortest team in the NBA in 2016-17. Today's NBA general managers value length and size, so you won't find a smaller backcourt combination than 5'9 5'7 Isaiah Thomas and 6'2 Avery Bradley. 7 footer Kelly Olynyk defends and rebounds more like a 6'9 stretch forward. Tyler Zeller, Boston's only traditional center, appeared in 51 games, albeit in limited playing time. Brad Stevens' streamlined 3-guard lineup featured 6'4 Marcus Smart as a small forward. Smart's 3-position switchability could be part of the reasoning for why Boston kept him instead of Bradley. Jae Crowder was asked to guard players four inches taller than him in the end of games. It felt like the players were constantly defending up a position.

The C's lack of size was exploited throughout the entire regular season and playoffs. Boston was 28th in rebounding percentage and surrendered the fourth-most second point chances, per NBA.com. Al Horford, whose rebounding numbers have continually decreased over the past four seasons, led the Celtics with 6.8 boards per game. For much of the beginning of the season, Bradley was the leading rebounder. 

Boston was killed on the glass in the playoffs. The Bulls posted a staggering 29.6% offensive rebounding percentage against the C's. It grew to 30% against the Wizards. If the Celtics are going to ascend to the level of the Cavaliers and Warriors, they cannot afford to give away so many extra possessions.

Boston attempted to answer their rebounding problem by signing the physically brutish Aron Baynes to a 1-year $4.3 million salary. Baynes is a legitimate 7 footers whose rebounding is his most marketable asset. The better question is whether he is too drastic of a stylistic change to fit within the Boston offense.

Boston's Floor Spacing

Last season, Boston's tactic for countering for their undersized roster was to space the floor with lineups that featured five capable 3-point shooters. The five-out lineup was a staple parameter for the offense last season. The C's shot the third highest number of treys per game by any team in NBA history, per Basketball Reference. Centers Kelly Olynyk, Horford, and Amir Johnson combined for 181/500 on threes, good for a respectable 36.2% clip. 

Neither Baynes nor fellow Boston neophyte Ante Zizic is a shooting threat. The Celtics newcomers played a combined 140 games last season, and neither attempted a 3 point shot. In fact, in their ten combined professional seasons, the newly acquired big men have managed just one 3-pointer total. Ironically, Baynes' one career make was against the Celtics in 2014. At least Amir was willing to take distance shots when left wide open. The same can't be said about the new centers. 

Here's where the Boston five-out offense is at its' best. Thomas and Horford set up a spread 1-5 pick and roll with three capable shooters around them. The pick is intentionally set thirty feet away from the basket in order to force Robin Lopez to defend Thomas beyond the perimeter. It allows Thomas to get a head of steam going toward the hoop. If the help comes, Isaiah could penetrate and kick to the open shooter. If the perimeter defenders stay, like they did here, Lopez is on an island guarding Thomas. Thomas is simply too quick for any center to have a chance against. Thomas was in the 95th percentile in scoring efficiency as the ball handler in the pick and roll. His decision making flourished in the spread offense. 

On that play, Lopez had to respect Al Horford's shooting capability. For centers like Lopez, defending beyond the three point line is an uncommon territory. Baynes, a more traditional big, typically finds his offense playing with his back to the basket. If the Celtics run the same play with Baynes, defenders simply aren't going to follow him out beyond the perimeter. Instead, the defender is more likely sink back into the paint and wait for Thomas to drive. Less operating room for Isaiah means more traffic at the rim and less open space for facilitating. 

Boston's ability to draw opposing bigs away from the basket was instrumental for the Celtics guard play at the rim. Thomas, who led the NBA in drives per game (12.9), was freed up to score at will when the basket was unguarded. The designed Marcus Smart post-up plays would have been thwarted if rim protectors weren't camped out near the three point line. In game 7 against the Wizards, Marcin Gortat looked lost trying to chase Olynyk near the 3-point line. 

What To Expect From The Bigs

Baynes should play a lot. For now, the New Zealander is the only true center that Boston employs other than Zizic, who is far too raw to be playing meaningful minutes in his rookie season. Baynes won't coerce opposing bigs away from the basket like Olynyk did, but he can still help to space the floor, especially in the pick and roll. Baynes shot 1.16 PPP as the roll man in the P&R last season, topping all of the Celtics rotational big men other than Olynyk's 1.17 PPP (Source: NBA.com). He has solid catching skills and surprising nimbleness in small spaces. Baynes is by no means an elite roller, but he has a deft scoring touch near the rim and should draw plenty attention away from Celtics ball handlers. 

Teams can spread the defense while still using a traditional non-floor spacing center. The Rockets and Cavs are perfect examples. The key is Clint Capela and Tristan Thompson's forceful rim running- each a master of the high pick and roll- with the ability to catch lobs and pocket passes. On any rim run, the help defender is forced to temporarily sink to avoid giving up a pass for an easy dunk or layup. That split second can open up shooters in transition or in the pick and roll. Watch here as Capela dives hard to the rim, forcing OKC's Taj Gibson to protect against the pass. That brief moment of defensive hesitation opened up a solid transition look for Trevor Ariza. 

The above play is simply about Capela out running Steven Adams. If Baynes can replicate Capela's hustle on plays like this, it will be huge for the Celtics floor spacing. 

Baynes is a fantastic screen setter. It may seem like a boring job, but it will be a critical one in the Celtics offense, especially if he starts. At 260 pounds, Baynes is an absolute load for smaller defenders to maneuver around. I see his screen setting being used off ball via curls, dribble handoffs, staggers, flexes, and more. He'll do the dirty work to help Thomas and Gordon Hayward get open for jumpers, and every team needs a player like that. Per NBA.com, Thomas ranked in the 86th percentile in off-screen scoring efficiency. Hayward ranked in the 83rd percentile. 

16-17 Per 100 Poss	FG	FG%	3PA	3P%	FT	FT%	ORB	DRB	TRB	BLK	PTS	ORtg	DRtg
Aron Baynes	6.2	.513	0.0	N/A	3.4	.840	4.8	9.6	14.5	1.7	15.9	114	106
Kelly Olynyk	8.4	.512	6.2	.354	2.9	.732	2.4	9.3	11.6	0.9	21.9	113	107

Stats via Basketball-Reference. 

Even with Olynyk's departure, the 5 out offense isn't going away. Al Horford will continue to play center in critical minutes, and Marcus Morris and Jayson Tatum offer intriguing new options at stretch 4. But with the C's shallow big man depth, Baynes should have an immediate impact, and Stevens will have to scheme up more conventional offensive sets. The spacing for four perimeter players around one big relies on the center being able to out hustle his defender. If Baynes can run the floor effectively, it will help shooters find the necessary daylight to launch their shot. 

Baynes provides a front court toughness that the Celtics have lacked since the departure of Kendrick Perkins. He may not fit last season's offensive scheme, but Brad Stevens has earned a reputation for maximizing the talents of every player on his roster. He'll certainly do the same with Baynes. The Celtic offense will look different with Baynes on the floor, but his heft and rebounding outweigh the schematic adjustments that need to be made to accommodate him.