Is small ball hurting the Celtics' defense?

In Boston's last two games, the Wizards and Mavericks have put up 117 and 118 (in OT) points respectively against the Celtics' vaunted defense and that's caused some to question Brad Stevens' decision to play small ball.  As CSNNE's A. Sherrod Blakely points out, the Celtics have not been as good on the defensive end despite a small ball lineup that includes its best defenders in Avery Bradley, Marcus Smart, and Jae Crowder:

But if you look at their last four games, Boston's defensive rating (101.5) slips down to eighth-best in the NBA despite winning three of those games.

Part of the slippage defensively has to do with the use of smaller lineups for longer stretches lately.

While there is no mistaking the fact that head coach Brad Stevens' decision to play with smaller units for longer stretches has helped win games, it does have its flaws which we saw the Dallas Mavericks do as good a job as anyone this season in exploiting.

The numbers don't lie, but they're not exactly the entire truth.  For what it's worth, Boston's stingiest four-man lineup that has played over 20 minutes together over the last four games has been that three-headed pitbull of Bradley, Smart, and Crowder plus Isaiah Thomas.  Over 23 of a possible 197 minutes, they're averaging a 98.8 defensive rating.  If you remove Thomas from the equation, AB/JC/MS are rated 91.8 over 37 minutes.

Blakely continues and looks at what might have been the problem in Monday's overtime loss in Dallas:

There were a number of offensive series where the Mavericks had a decisive matchup in their favor, like when Dallas would run some pick-and-roll action which left 5-foot-9 Isaiah Thomas out near the free throw line having to defend 7-foot Dirk Nowitzki or created an isolation situation for one of Boston's big men and one of Dallas' guards.

Seeing Thomas give up over 12 inches to Dirk in the post looksig daunting, but the truth is, they didn't exactly exploit these type of mismatches.  By my unofficial count, 17 out of Dallas' 93 FGA's came out of isolation post ups on smaller defenders and the Mavs only converted 5 times.  Nowitzki was a 3-for-13.

This whole discussion reminded me of an interview that Stevens had with Grantland's Zach Lowe.  One of the topics they discussed was the analytic inefficiency of post ups in basketball and how it was only really used as a vehicle to play inside out.  Not surprisingly, the Celtics use it rarely (23rd in the NBA at 6%) and even less surprisingly, they happily oblige opposing teams to post them up (3rd in the NBA at 9.7%).

The Celtics should be see a healthy diet this weekend with back-to-back games against the bigger Bulls and Sixers, but they shouldn't overreact.  The Mavs hit a ridiculous 16 threes on Monday, including 4-for-4 in overtime.  As Stevens points out, closing out on shooters is going to be very important when they go small:

"When we go small which is something that we're just going to have to figure out, we're going to have to be awfully aggressive and active and close to the ball," Stevens told reporters after Monday's loss. "Otherwise we're not going to impact it. If we're not impacting it, deflecting some of those passes, we're not going to look big closing out. And so we need to make sure we're better than that. It's easier said than done."

When the Celtics gambled on double teaming Dirk, he made them pay by making the right pass and putting the entire defense in jeopardy.

In this first GIF, Smart chipping down with Dirk almost in the paint is a smart play.  When you watch the clip with sound, you can hear Avery yell out, "I've got you, Smart!"  Marcus disrupts Nowitzki's ISO and gets a hand on it, but unfortunately, Dallas rotates the ball and they get a good look.

This one drives me a little crazy.  Smart goes for the steal in Dirk's blind spot, but he quickly recovers and passes to Raymond Felton.  It's a poor close from Evan Turner, Thomas zips right by without making a play on the driving Felton, and neither Crowder or Kelly Olynyk contest the lay up.  This can't happen.

Here are the threes from overtime.  Outside of Smart getting held up on a couple of blocker screens, the close outs and contests are pretty good; Dallas was just hitting shots that night.  However, with the Celtics embracing small ball, they are allowing more shots from beyond the arc.  For the season, they rank 8th in the league in allowing the fewest three pointers at 22.4 3FGA's and 4th in the league in 3FG% at 32.1%.  Over the last four games, opposing teams have shot 28.3 3FGA's at a 32.7% clip.  The Pacers, Suns, Wizards, and Mavericks all rank in the top half of the NBA in three point attempts, but the Celtics should still be opposing their defensive plan on other teams.  It's a small sample size and may not even be attributed to small ball, but it's definitely something to monitor.

After Saturday's win in Washington, Stevens admitted that small ball isn't a long term solution, saying "The guards are still young -- they're all young -- but they all have had good experience ... we're going to keep shuffling those guys around, and Jonas (Jerebko) will play a little bit at the small forward. The more you can, the better, but you can't do it the whole game. It's just not feasible long-term."  It's definitely worked in spurts so far.  Whether it was Smart pestering Kristaps Porzingis or the four steals that won the game against the Pacers, it's still only a gimmick.  That's why Jared Sullinger is back in the starting lineup next to a more traditional big in Amir Johnson.

What should be really interesting is how Danny Ainge approaches the upcoming trade deadline, this summer's draft and free agency, and the rebuild as a whole.  The roster is chock full of guys that can play the small ball style, but should DA target potential trades and players that would also fit (like a Ryan Anderson or Danilo Gallinari) or round out the team with more traditional fits like another rim protector or straight shooters?