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On the eve of his team’s 2019-20 season-opener, All-Star blogger Gordon Hayward boldly wrote that, “anyone expecting [the Boston Celtics' defense] to fall off this year … might be in for a little shock.”
The prevailing notion after Boston’s offseason makeover, one that saw the team lose backline defensive anchors Al Horford and Aron Baynes, was that the Celtics’ defense was going to take a considerable step backward. Hayward’s proclamation could have been written off as standard preseason optimism but challenged last week on his suggestion, Hayward didn’t relent.
"I just think that, because we’re a little smaller, people aren’t expecting a lot from our defense,” said Hayward. "I think we have a chance to be really good on that end. I think it’s going to take a lot of work from us. But from what I saw [before the season], we definitely have a chance to be really good defensively.”
The Celtics sit at ninth in the NBA in defensive rating entering Wednesday’s showdown with the Milwaukee Bucks. Boston is allowing 100 points per 100 possessions, which is seven points less than their mark last season when they finished sixth in the NBA. It’s fair to wonder if a larger sample size will start to uncover some of Boston’s more noticeable flaws.
Heck, we might have a better idea after Wednesday night based on how the Celtics and their dinged-up frontcourt fare against reigning MVP Giannis Antetokounmpo and a Bucks team that ranks sixth in the NBA with an offensive rating of 110.4.
Let’s examine some of the early season numbers that show how Boston has put together a top-10 defense to this point — and whether it’s sustainable.
Opponent TO%: 20.8
The Celtics have been steal-hunting fiends with five players averaging better than a steal per game, including Jayson Tatum, who has eight swipes in three tilts. Robert Williams might be best known for his volleyball blocks but he’s added five swipes in just 47 minutes. Boston is making opponents pay for sloppy passes at a rather absurd rate.
The Oklahoma City Thunder led the NBA in opponent turnover percentage last season at 16 percent. Over the past decade, only a small handful of teams have reached 18 percent or better in turnover percentage. The grit-and-grind Grizzlies posted the best mark of the past decade at 18.5 during the 2011-12 season.
Stevens implored his perimeter players to increase ball pressure this season. Those back-line departures took away the safety net that Boston wings once enjoyed. Boston’s increased pressure isn’t just tangible in the steals, you can see it in the number of deflections created as well, including Tatum with a team-high 10.
"Listen, we’re not gonna be a very good defense if we don’t play with a little bit of ball pressure. We’re just not,” said Stevens. "We’re not big enough in the interior. We’re not big enough at guarding post players at the 4 and 5 if we just let passes go where they want. If we let teams operate in a comfort zone we’re not going to win very often unless we really make shots on a given night.
"Our strength lies in our perimeter’s ability to move our feet and pressure and be versatile and our bigs can read when those guys get beat and have to react to that threat. We have to get better at all those things. I don’t think we’re as good as we can be, but that’s what we have to be if we’re gonna be any good defensively.”
Maintaining such a high turnover rate — all while the Celtics themselves have taken care of the ball at the other end — seems unsustainable. But Boston can thank the turnover disparity for keeping them competitive while their shots defied them early in the season.
Opponent eFG%: 47 percent
The Celtics own the third best opponent effective field goal percentage in the league — a metric that adjusts shooting percentage for the value of a 3-point shot — at 47 percent.
The question, of course, is whether that’s a factor of Boston’s defense or if opponents have simply missed shots early in the season. In their three games thus far, the Celtics have played offenses that rank 24th (Knicks), 19th (76ers), and 17th (Raptors). While those teams might all eventually climb, they clearly weren't firing on all cylinders out of the gates.
Boston has seemingly done a good job chasing teams off the 3-point line, allowing only 30.7 3-point attempts per game (seventh lowest in the league) and opponents are shooting 34.8 percent on those shots (about middle of the pack in the NBA).
Charges Drawn: 2.67
The Celtics are tied for the NBA lead in charges drawn per game with Kemba Walker having racked up four of the eight total charges drawn. Rookie Grant Williams has two and Marcus Smart and Semi Ojeleye each have one. Smart, notorious for his offensive foul-drawing ways, looks like the most excited person in the building each time Walker earns a whistle while giving up his body to create a momentum-shifting turnovers. Charge-drawing is one aspect of Walker’s game that, if you didn’t watch him every night in Charlotte, you probably didn’t know how good he is at drawing those calls. That’s important given the way teams will try to exploit Walker’s size.
Noted Stevens: "He’s just always been a guy that’s willing to put his body on the line.”
% Loose Balls Recovered Def: 58.3
One of the hallmarks of Boston’s best defensive teams is a desire to win 50/50 balls with Smart routinely throwing himself on the ground in pursuit of a loose ball. The Celtics ranked second in the NBA last season while recovering 61.6 percent of all loose balls while on defense, and they rank eighth so far this season at 58.3. If Boston ratchets up the pressure on the perimeter, it should create more opportunities to pounce on 50/50 balls this season.
The Concerns: Rebounding and rim protection
For all the good the Celtics have done through their first three games, there are concerning areas. The Celtics rank 26th in the NBA in defensive rebound percentage at 69.5 percent. When the team goes small, it leaves Boston particularly vulnerable on the glass and Hayward admitted it puts an onus on perimeter players.
“You gotta be smart, you gotta be able to think the game and kinda anticipate different things,” said Hayward. "Certainly your rotations have to be good, especially if we’re going to double team, which we might have to [against star bigs]. Communication has to be very good as soon as you start having to rotate and scramble.
"I think more than anything, we’re going to have to gang rebound and that’s going to be a huge thing for us throughout the year. Making sure that the wings coming in to rebound, the guards come to rebound because sometimes the big’s going to be fighting their big so we’re going to have to make sure we rebound.”
The big question: Who defends GIannis?
During the playoffs last season, the Celtics leaned heavily on Horford and Baynes to defend Antetokounmpo. Horford logged nearly 25 matchup minutes and Baynes took another 7:25. Marcus Morris was next in line at 5:38. No one else on the team was higher than 5:38. Which is to say that Boston lost nearly 75 percent of its total matchup minutes against Antetokounmpo this offseason (though Kyrie Irving should have never had 4:04 on him to begin with).
Boston’s transition “wall” looks far less intimidating now without players like Baynes and Horford as the centerpieces trying to deter Antetokounmpo attacks. Now it’s players like Tatum and Robert Williams who have to try to provide that resistance. Grant Williams has the strength to play but will be giving up a half of a foot in height.
It will be fascinating to see how Boston’s defense holds up and whether all the attention on Antetokounmpo allows Khris Middleton and Co. to feast from the perimeter.
Wednesday’s matchup ought to go a long way towards telling us exactly how good Boston’s defense can be this season.
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