There are a ton more factors you are not considering. The Celtics give up a ton more open jumpers because of the way they have to defend to compensate for Thomas. Double teams to get the ball out of his man's hands cause problems elsewhere on the floor. He isn't keeping his man from shooting help defenders are and as a result leaving the rest of the defense scrambling and rotating to compensate.
I believe the Defensive Rating with lineups including him would account for that. Those defensive ratings are both good and bad. The problem is that there is no way to verify what you just said, or to verify that it is his fault. Some stats would indicate that some of those are as much Bradley's or Crowder's fault.
There is a pretty straightforward explanation of the team defensive numbers though, that shift the blame fairly clearly off of Thomas as an individual.
If you look at the defensive rating of lineups with all three of IT+AB+MS on the floor (i.e, "3-guard" lineups) they have a DRtg of about 116. In other words, truly, horrendous. In fact, this pattern holds true for all of our "3-guard" lineups (involving any three of IT, AB, MS & TR). Those lineups were just awful on defense.
The motivation for using those three-guard lineups was obvious in the case of the ones with IT: They had similar hefty offensive rating numbers. Unfortunately, the ones without IT had horrible offensive ratings.
3-guard lineups accounted for a very large percentage of IT's minutes on the floor last year:
IT+AB+MS : 418 minutes, 115.0 DRtg
IT+AB+TR : 30 minutes, 123.7 DRtg
IT+MS+TR : 118 minutes, 116.0 DRtg
That's a huge 566 minutes, a solid 20% of Thomas' minutes on the floor this year at a 115.7 DRtg.
In 1766 minutes of exclusive two-guard lineups (IT plus just one of AB, MS or TR), the DRtg was a much better 112.3.
In the 773 minutes that IT played just with Avery (no Smart, no Rozier) the team defensive rating was 109.1 That's a pretty hefty difference from the numbers up above.
The point of this is that, stats like DRPM were almost certainly being heavily swayed by the statistical weight of the Celtics' super-heavy use of 3-guard lineups last year. It's notable that Avery Bradley, who like IT had a huge share of his minutes in such configurations, also scored poorly in DRPM.
Here next is where there is likely reason for optimism going forward:
In the 247 minutes IT played _without_ any of Avery, Smart or Rozier -- i.e., primarily one-guard plus all wings & bigs (most of it with Brown, Crowder, Horford + Amir), the team defensive rating was 104.9 (while still maintaining a hefty 112.4 ORtg!!).
THAT latter number is probably closer to what we might expect with the new roster going forward, where we play IT more often with either 3-wings and a big or 2 wings and 2 bigs.
Danny has given Stevens the tools to play much bigger around Thomas this year. Hopefully he will take advantage of those tools.
Edit: Fixed quoting.
Topic: Isaiah Thomas' Defense is Better than You Think (Read 12854 times)