This season, every contender has shown a chink in their armor. We talked about the Spurs defense struggling lately. Miami and Los Angeles have had ugly losses to weak teams. Chicago is untested and unproven in the playoff cauldron.
And Boston’s defense may be a concern.
Ever since the Kendrick Perkins trade there was the question of if the Celtics defense would be the same. Zach Lowe at Sports Illustrated’s Point Forward broke out the numbers and found that overall the defense is pretty close to what it was pre-trade.
However, overall includes the outlier of the Bucks scoring just 56 points Sunday (and with their terrible offense it is an outlier). Lowe takes that game out of the equation and finds Boston has allowed 102.8 points per 100 possessions since the trade. That’s not bad (it would be about 10th in the league) but it is worse than Boston’s season average of 97.7 (using Hoopdata’s numbers).
What’s more concerning is why the defense is worse.
1) Opponents are hitting a much better percentage of inside shots. In those nine games, teams have made 123-of-193 at the rim (63.7 percent). For the season, Boston ranks second in this category at a shade worse than 60 percent. That 63.7 percent mark would rank about 17th overall…. Another small red flag: Those nine foes have assisted on 58.5 percent of their close baskets, a huge jump from an average assist rate on close shots of about 51 percent for Boston’s opponents this season. No team has allowed an interior assist rate as high as 58.5 percent over the full season.
2) Opponents are shooting about 37 percent from three-point range during those nine games, up from a season average just shy of 34 percent. A small change, but perhaps a notable one, given the close relationship between a team’s interior defense and its ability to protect the three-point line.
We must point out that nine games is a very small sample size, so we want to be careful about jumping to conclusions. There also are mitigating factors, for example Nenad Krstic is not a bad interior defender and is working hard to learn the Celtics system and fit in. Shaquille O’Neal will be back for the playoffs and he certainly is a big body that can alter shots and change things in the paint. Finally, they still have Kevin Garnett healthy and he is the heart of the defense.
It’s no time to panic. But it is something to watch as we head toward the playoffs. Because it is a chink in the armor.