One of the things we talk about all the time is that each team is it’s own entity and even when we’ve had more guys back and more continuity the last couple of years, you still have to work on all the important things, all the things that add up to ultimately just giving yourself the chance to win… -Brad Stevens

The challenge of building a cohesive team exists every year, but Brad Stevens knows that when you change eleven players on a roster it will be bigger than normal. The 2016-17 Celtics were a team of ball movement and floor spacing but with Kyrie Irving and Gordon Hayward coming in will that continue or will Stevens re-make the team in a new image?

Who are the 2017-18 Celtics?

To try to answer that we first have to determine who they’ll physically be. Last season the Celtics’ regular rotation went 9.5 players deep. While the team is only returning four of their 15 players, all four were at least in the rotation.

I’ve excluded Jonas Jerebko from the 2016-17 rotation because, while he was part of some of the team’s best units and played nearly as many minutes as Rozier, he used far fewer possessions and the analysis just works better matching nine players to nine players. The tenth player this season will probably be Semi Ojeleye or Guerschon Yabusele. While we don’t have much information on them yet, they look like they’ll be low usage combo forwards taking a healthy number of their shots on open threes, like Jerebko did. The players I have included made up 86% of the team’s total minutes played.

The projected minutes and numbers are my own guesstimates, but if they come close to that the team won’t play any younger than last year’s. Most of the youth that has drawn some questioning glances is unlikely to see NBA floor time. The team will be taller and longer by playing one fewer traditional big but more than making up for that with a bigger backcourt.

One thing that stood out in trying to make these projections was how many players get squeezed by adding a second high-usage player to the mix. Marcus Morris, for one, could really feel the pressure as he was credited with over 1,100 possessions used in 2,565 minutes for Detroit, both more than any player on the Celtics other than Thomas.

How do the new Celtics play?

Todd Whitehead (@CrumpledJumper) has recently been writing on Nylon Calculus about how to statistically define offensive roles and which players fit into them. You should read the details on exactly how he did it, but in short he divided 300 players into the same designations that Brad Stevens uses (ball handlers, wings, and bigs) then grouped them by how often they used a possession in each of the ten play types that Synergy Sports tracks for NBA.com. He ended up defining 18 different offensive roles and was kind enough to provide me with all the data.

A problem Stevens will have to deal with is that Danny Ainge has traded off a lot of spot-up shooting and off-ball movement for ball-handling and isolation play. This extends well beyond the swap of Thomas for Irving. Hayward needs the ball a lot more than Avery Bradley did. Marcus Morris might be seen as a swap for Jae Crowder but they play very differently, and what Morris does overlaps with a lot of his new teammates.

The loss of Olynyk also hurts the spot-up shooting, not just because he makes threes at a high rate but simply because he’s willing to take them. Amir Johnson and Aron Baynes map to the same roles but they’re on opposite ends of the designation, about as different as two players could be and still fall into the same class. The group of Crowder, Olynyk, and Johnson had a far higher percentage of their possessions come from spot-up shots than Morris and Baynes did or Tatum projects to.

At least a few players will need to evolve their roles this season or the offense will look drastically different than last year’s. There’s also the reality of only one ball being in play.

There’s an inclination to say that Stevens will just turn all these players into what he needs them to be but he hasn’t always operated like that. There will be a balancing act here in trying to stretch players into new roles without taking them too far out of their comfort zones.

Kyrie Irving vs. Isaiah Thomas

The change that has received the most attention is Kyrie replacing Isaiah, for obvious reasons. It’s been noted by many people that Irving plays in isolation far more than Thomas did. What might not be recognized is that Kyrie finished plays in the pick-and-roll just as often as Isaiah; the isolations come at the cost of actions like spot-ups, off-ball movement, and hand-offs.

This seems counterintuitive as Kyrie was playing with LeBron, who is brilliant at getting these type of shots for teammates. If Stevens does focus on getting him more of those types of shots it actually shouldn’t come at the expense of isolations, where he is ridiculously efficient. Some of those shots should come out of his pick-and-roll play. If he is able to make that shift it should help everyone gain space to work.

There has also been quite a bit of talk about getting Kyrie working the dribble handoff game like Isaiah did, but he didn’t score nearly as efficiently in those play types last season. These aren’t super efficient plays in general. This may be a case where Brad invests possessions in seeing if Al Horford is simply a better partner for handoffs and, if not, they run them less frequently.

Gordon Hayward vs. Avery Bradley

Hayward and Bradley are very different “second options” to craft plays for, but Gordon is more efficient in basically every play type so there are a lot of ways this could go. It’s no surprise that he’s far more comfortable with the ball in his hands than Bradley was, but it might be one that he’s better shooting on the catch off movement than Avery was. The curl plays that Bradley made his name on might be even more effective with Gordon running them.

Hayward and Bradley were basically a wash on straight spot-ups and as cutters. When Hayward doesn’t have the ball, we may see him doing many of the things Bradley used to. He’s bigger and more dynamic after the catch so the plays may not end the same way; but not everything needs to change here.

Marcus Morris vs. Jae Crowder

The difference between these players is stark. Crowder was a dramatically more efficient offensive player than Morris last season but in lower volume. Now that Crowder is gone, I suspect a lot of fans will finally recognize just how good and important he was. He embodied the “3-and-D” role and stretched defenses to the three point line all the way around the arc.

Morris plays more like early Paul Pierce, but without the ability to make the ball go in the hole. Entirely too many of his possessions included multiple dribbles. He isn’t a particularly effective scorer in off ball situations but his frequent pick-and-roll play was an unmitigated disaster. Stevens is going to have to take all of those play types out of his game.

This should be a concern for Celtics fans as Stan van Gundy was an early proponent of the spread pick-and-roll and didn’t, or couldn’t, get Morris to accept the 3-and-D role that plays a huge part of that.

Aron Baynes vs. Amir Johnson

Similar to with Crowder, Celtics fans who questioned Amir Johnson’s value are going to learn it by his absence. Every C’s fan (rightly) delighted in making fun of Amir’s slow release but his outside shot did have to be respected as he made 40% of his threes and took nearly one a game . He used the shooting ability to not only space the floor for Isaiah but also create space for himself to get easy hoops off cuts.

Baynes is a traditional pick-and-roll big. His profile looks more like Tyler Zeller’s, who was very effective in his first season in Boston before his mid-range jumper abandoned him and the team transitioned to a more open system. Baynes can make a 15′ baseline shot but not much else outside of the paint.When you put him in pick-and-roll he’s an ok finisher but has zero passing ability so teams will be comfortable trapping Irving or Hayward and letting Baynes try to work a 4-on-3. Smart-Baynes pick-and-rolls are doomed to failure.

Baynes was a solid signing for the cap exception Boston had available, but the Celtics could acutely feel the loss of Johnson and Olynyk when they’re trying to run an offense with Aron on the court in their place. With the open 15th roster spot, Ainge may want to look for a stretch-5 instead of a dedicated rebounder, if the choice is between one dimensional bigs.

Composite Jayson Tatum vs. Kelly Olynyk

Olynyk and Tatum are very different players but the rotation currently looks to be dropping a big for a wing and Kelly was the most “wing-like” big so I’m using him for that comparison. Tatum is the tallest of the wings and projects to rebound like a power forward so I think matching him against Olynyk, and Morris against Crowder, makes more sense than flipping those.

We don’t know how Tatum will actually play but to make a projection I used four common player comps for him. Carmelo Anthony and Harrison Barnes are the only two players in the NBA last season that fell into the “ball stoppers” role. Two others, Rudy Gay and Jabari Parker, were in the “secondary creators” and “glue guy” roles. That combination gives us a player with a versatile but somewhat stationary scoring set.

As with other player changes the team has made, we’re losing spot-up shooting here. Personally I believe Tatum will develop into a very good spot-up shooter from three, but he doesn’t seem comfortable out to that range yet. This looks like a case of swapping a specialist for a generalist which is not always ideal for role players on offense. That will serve everyone well if he develops into a star but probably not as much this season.

Challenges and Opportunities

Challenge: Spacing

If you scroll back up through the player comps and focus on the shot charts you’ll see that all of them have the new player taking more of their shots from mid-range than the departing one did. Last season’s team were third in the league in percentage of shots taken from three and sixth lowest in percent taken from mid-range. To match that, Brad Stevens will have to change the style of multiple players. Kyrie and Hayward should be able to stretch out relatively easily; both are very good 3PT shooters.

The role players are where this is a major issue. Aron Baynes has taken seven three pointers in his career; he is not going to move behind the line. Marcus Morris can move back out of mid-range and focus on taking more of the shots that Jae used to, but he’s an average 3PT shooter for his career and only made 33% from the arc last season. We don’t know when Tatum will get comfortable out there.

Crowder, Olynyk, and Johnson were all above average 3PT shooters and if you add Jerebko into the mix the loss gets even worse. It’s tempting to think that a team with Irving, Hayward, and Horford can’t suffer from spacing issues but operating space comes from the fourth and fifth guys on the court, not the ones around the ball. This is a place were Semi Ojeleye might be able to muscle his way into a regular role. He showed in Summer League that he understands what 3-and-D means; his defensive versatility has been called out by Stevens but it might be his ability to stand 24′ from the hoop and make stand-still shots that gets him on the floor.

Spacing would be an issue just based on the changes being made, but three of the four returning players compound it. No one respects Marcus Smart’s shot. Terry Rozier made shots in the playoffs but he has a long way to go before defenders fear him. Jaylen Brown has showed some flashes, particularly from the right corner, but until he goes a few months actually making his looks the defense is going to be willing to sag off him to clog things up for Irving and Hayward.

There’s no easy fix here. The team can play a system that demands players move behind the line more often than they’ve been used to, but that also has to translate into made shots and at the moment we don’t know if that will happen.

Opportunity: Transition

The 2015-16 Celtics were also spacing-challenged with Evan Turner running second unit and Isaiah doing more of his work inside the line. To make up for this, they became very aggressive on defense and got out in transition off live-ball steals. They got away from that last season but the offense was more than fine because of Thomas and shooting.

This season they have a number of players who excel in transitions and should play to that. Gordon Hayward is one of the most unstoppable transition players in the league and Marcus Morris is well above average. Jaylen and Jayson have the athleticism to both create turnovers and finish in transition.

Unless they sign someone like Andrew Bogut to the 15th spot, and that player gets minutes, the team is also going to have less rim protection than they did last season. Amir Johnson has always been a deterrent at the rim, even as his legs betrayed him. Olynyk isn’t a shot blocker but he does get in position and contest. Aron Baynes can do the same but will play less minutes than the bigs he’s replacing. The trade-off is for length and athleticism on the wing, so swapping rim protection for steals and using that to juice an offense that might not hum in the half-court is worth trying.

Challenge: Floor Balance

Last season, the Celtics most often set up with Thomas or Smart on the right, Crowder on the left, and Bradley working right to left. With Horford screening for Isaiah and then rolling or popping to the top of the key, the floor was well balanced.

Kyrie, Hayward, and Morris were all majority “right side” players last season, as was Jaylen. I don’t know if this was a matter of scheme for all their teams but if they’re inherently more comfortable on that side, someone is going to have to get uncomfortable. This isn’t a problem across the board as Tatum seemed more at home on the left in Summer League and Marcus Smart makes more of his spot up shots from the left, as long as he’s all the way in the corner.

The short charts show this to a certain extent, but watch Irving and Hayward highlight reels and it really stands out.

Opportunity: Coaching

The issues with spacing and floor balance and a tendency towards isolation are all legitimate problems right now but Brad Stevens has time to work. The rotation will be as young as it was last season and the deeper bench even younger. From the rotation, only Aron Baynes is an unrestricted free agent after the season so Stevens should have multiple years to work with many of these players. Everyone wants immediate results but that’s probably not going to be the case here.

Look at how Avery Bradley’s shot mix and effectiveness changed over the course of Stevens’s tenure:

It can be a slow but noticeable growth process for some players. Jaylen Brown and Jayson Tatum will have growing pains in trying to modify their game to fit what Stevens wants and the modern NBA demands, but they’re in a place where that can happen. For this season it might be frustrating but the work eventually pays off.

In the meantime, Stevens has shown a willingness to be flexible with his system. He’s more Greg Popovich than Phil Jackson or Mike D’Antoni. For example, take Evan Turner. The 2015-16 team had no real choice but to rely on him and so Brad built offensive sets around what he can do. The team didn’t play particularly well when he was out there, but they survived and he had an ok season. When he signed in Portland they did what I think most teams would try and asked him to stretch his game. The result was a somewhat healthier shot mix but even less efficient total scoring.

Having watched that, I don’t know if the Celtics will immediately look to change Kyrie’s game away from isolations and into more movement. Irving is legitimately exceptional in isolation, scoring at the same rate as Steph Curry does in aggregate. Is it really smart to take too much of that away from him? Yes, he has the unquestioned ability to play other ways but I think it will be more a gradual progression than trying to plus Kyrie into the “Isaiah role” that was so effective last year. We may see the same with Marcus Morris, though that looks like more of a problem to fit in.

What to Watch For

This is not going to be an easy transformation. Brad Stevens seems to relish the opportunity to take it on but it will be a real slog sometimes. Fans should expect the offense to bog down more often than it did last year and for some of the players to get in each others’ way from time-to-time. Some of that should (and will) be chalked up to “needing time to mesh” but some of it is also the inherently difficult fit of these role players around these stars.

Danny Ainge has already hinted, maybe jokingly, that there could be even more changes to come. I would be searching for more of a shooting big than a rebounder and looking around for contracts that might match up in a Marcus Morris trade. With time I’m sure Stevens could find a way to use Morris, but with time he’ll be replaced by Brown and Tatum anyway.

I think it will be important for Stevens to stagger Irving and Hayward. The “all bench” units that he has deployed in the past will now be spacing death. I’m concerned that Marcus Smart will be further stifled in all of this but maybe his fate is to just always be a gap filler and never get his chance to have a unit built around his strengths.

The offense this year will probably look like a mix of the last two. It won’t be the ball-moving clinic of last season but should have more motion than the season prior and can hopefully create transition opportunities like that team did. Brad Stevens has a tough task on his hands but you could hardly ask for a better coach to tackle it.

All shot charts were created using BallR by Todd Schneider and can be viewed in higher resolutions here. Thanks to Todd Whitehead for play type information and role designations. Play type data is from stats.nba.com. You can follow me on twitter @dangercart.