3 Areas Boston Celtics Must Upgrade This Offseason

The Boston Celtics won just 25 games this season, and like most 25-win teams, they head into the offseason with serious improvements needed in a variety of different areas.

Their entire offense flailed, parts of their defense stumbled, and they lacked key elements in several places that stand as the difference between successful teams and those that can’t get out of their own way.

Identifying problems is the first step to getting better. Here are Boston’s most dire on both sides of the ball.

Christopher Szagola

Three-point shooting

Boston can’t score to save its life. The Celtics ended the year third worst in field-goal percentage (same goes for effective field-goal percentage and true shooting percentage), third worst in turnover rate and fourth worst in offensive rating.

For whatever reason, they played at a league-average pace despite having the type of talent (or lack thereof) reserved to go much faster. The most disturbing area, though, was their lack of three-point shooting.

The Celtics finished the year 28th in accuracy behind the arc. Avery Bradley and Jerryd Bayless each shot a respectable 39.5 percent, but the team as a whole couldn’t get it done. After his hot start, Rajon Rondo ended below 30 percent (meaning that shot might have to be removed from his repertoire), where he was joined by Phil Pressey, Jared Sullinger and Gerald Wallace.

Three-point shooting is key in today’s NBA. It provides spacing, which opens up driving and passing lanes. It turns post-up opportunities into a pick-your-poison choice for a defense that needs to decide whether doubling down is worth it.

Boston actually finished slightly below average from the corner—that's a good thing—on both percentage and attempts, but it needs more help there, too. The inexpensive Chris Johnson was a bright spot (45.7 percent shooting from the corner), but that isn’t enough.

Making and taking a lot of outside shots is critical, and the Celtics need to adjust their personnel to allow head coach Brad Stevens to take advantage of all the benefits of having a three-point shooting team.

But Boston finishing as one of the most pathetic offenses in the league isn’t solely attributed to its poor outside shooting.

Charles Krupa

“Go-to” individual scoring

The word “isolation” is stigmatized in most basketball circles. People read it and think one player is taking on an entire defense by himself. It isn’t smooth. It’s not efficient. It takes four other players out of their rhythm.

All these points can be more than true in the right context, but that doesn’t mean having a very good isolation scorer is without value. The ability to create offense one-on-one is incredibly important right now, and all the league’s best offenses feature players who can catch the ball in the post or on the wing and score or draw a foul whenever they want.

These players create matchup problems and bend defenses at their will even when they don’t have the ball. The Celtics finished the year 21st in isolation efficiency, scoring just 0.81 points per possession when iso sets ended with either a turnover, field-goal attempt or free throws, per mysynergysports.com.

The lack of a single player who can create for himself burned Boston time and time again. The Celtics routinely got lost late in the shot clock, and nobody was talented enough to bail them out.

Only two players on the roster finished the season making over 50 percent of their two-point field goals, and one of them was Wallace. Kris Humphries was the other.

Jeff Green was supposed to be this player, and nobody on the team averaged more than his 16.9 points per game. But the burden of being a No. 1 option got to him almost immediately, and his season-long struggles were a major reason the Celtics couldn’t impose their will offensively.

From NESN’s Ben Watanabe:

"

Aside from the part about the Celtics’ endorsement of Green expanding his role, almost nothing in Ainge’s evaluation is accurate. Green has never been a great 3-point shooter off the dribble or above the break, and while he can get to the rim seemingly at will, he seldom asserted himself to do so. He somehow pulled off the difficult trick of posting a career-high usage rate (23.6 percent) while falling significantly in player efficiency rating (to 13.1 from 15.0 last season).

"

The Celtics also failed to live at the free-throw line, primarily because they had nobody on the team who could consistently get there. They wound up 27th in free-throw attempts per game.

Offense was this team’s major weakness, but its defense wasn’t exactly a world-beater.

Rim protection and perimeter defense

Michael Dwyer

These two go hand-in-hand because one has a significant effect on the other. Good perimeter defense keeps opponents out of the paint, in turn limiting attempts at the rim and helping bigs stay out of foul trouble.

Celtics opponents made 61.4 percent of their shots in the restricted area this season. That figure is slightly below league average—a relative victory for a Celtics team that had no true center all year long, but not something to hang your hat on.

Boston was undersized and undermanned in the frontcourt, with Humphries and Sullinger often playing out of position at center, and rookie Kelly Olynyk (the team’s only seven-footer) still learning the ropes of team defense.

Worse, though, was the number of attempts so close to the rim. The Celtics allowed 2,331 shots in the restricted area this season, sixth most in the league. Bradley is an incredible defensive presence, but one guy can't do it alone, especially after Wallace’s season ended due to injury.

And as great as he is, Bradley is nowhere near tall enough to guard the league’s top-tier wings. LeBron James, Kevin Durant and Carmelo Anthony? No. Boston needs a longer, more athletic defensive presence to make large, high-volume scorers work hard on a possession-by-possession basis.

Green is not the answer. Wallace was solid this year but obviously isn’t the long-term solution. Brandon Bass moves wonderfully for a man his size, but it isn’t logical to keep him out on the perimeter. He’s capable of staying out on guys if there’s a switch in the pick-and-roll, but that’s about it.

David Goldman

The Celtics did a fantastic job defending the three-point line (especially the corners) all year, limiting attempts with tough closeouts, but they need another wing defender (Aaron Gordon?) and a shot-altering presence on the back line (Roy Hibbert? Omer Asik?) before this end of the floor can truly be seen as a strength.

On offense they need...just about everything except a starting point guard. But three-point snipers and a dependable lead scorer would do wonders. It's a stretch to assume the Celtics will take care of all these weaknesses in one summer, but it'll be interesting to see the order in which they are addressed.

All statistics in this article are from Basketball-Reference.com or NBA.com/Stats (subscription required) unless otherwise noted.  

Michael Pina covers the NBA for Bleacher Report, ESPN’s TrueHoop Network, Sports On Earth, Fox Sports, Grantland and The Classical. His writing can be found here. Follow him @MichaelVPina.