Kelly Scaletta on Twitter: An estimate of how much each players "defense" has cost his team in total points this season, based on DRPM.
twitter.com/KellyScaletta/status/803258303899...
twitter.comPosted Nov 28, 2016, 7:49 PM UTC
833
twitter.comKlay never seems to have good defensive advanced stats.
Maybe most people's eye test is biased towards his strength (on-ball perimeter D, staying in front) and the problem is what he is missing (steals, blocks, boards...). It's possible that fans and commentators have kept repeating ideas like "steals/blocks aren't a sign of good defense" to the point where the defensive box score is underrated.
Maybe he built his rep on some solid performances on point guards in the playoffs a few years ago and he hasn't maintained it.
It's kind of a mystery.
9
it's just hard to quantify on-ball defense. tracking tech has helped but the only really consistent measure is opponent FG% and i don't know how many advanced defensive stats incorporate that.
6
It's even harder to quantify off-ball, too - there are a lot of gray areas introduced by more complex defenses about whose responsibility it is to be where and judging how effectively a player has done that can be hard even for a trained eye looking at tape.
3
you're right, it's maybe more accurate to say that it's hard to quantify any defense that doesn't directly result in a TO, missed shot, or changed possession (steal/block/rebound/etc.)
1
Like Avery Bradley, his talents are mostly on the ball defense, which advanced defensive stats tend to have a harder time judging. Bradley and Klay both get a lot of praise around the league as top defenders, but the advanced stats tend to disagree. Unlike in baseball where the advanced stats almost always match the eye test from fans and I haven't seen actual talent evaluators (scouts, baseball prospect raters etc), advanced stats aren't always a even tool with traditional talent evaluation measures.
1
A lot of it has to do with rebounds.
1
https://pbs.twimg.com/media/CyW_KlXVEAAFAcl.jpg
-This is the chart.
5
Is Dame as bad as this chart show to be?
5
CJ helps him for sure
1
In theory DRPM is supposed to adjust for rotations (someone please correct me if I'm wrong), so we shouldn't see that here (though the effectiveness of that adjustment is a separate discussion entirely).
1
Yes, the idea is to use those periods when they don't play with each other to make the picture clear. Doubt it works well if those periods are just not big enough.
2
Seems like Rose takes a hit because of the knicks horrid PnR coverage, but he really hasn't looked that bad on defense at all.
4
Rose was awful at PnR defense last year, I haven't seen anyone worse at getting around screens.
2
knicks fan have in starting jose last year, but even his rating hasn't been as bad as rose's.
it's less rose's fault though on the PnR, and more the positioning of the knicks bigs on the PnR. they stay too far back to adequately contain the guard coming off the screen.
he hasn't been lock down by any means, but he's been solid. on the other hand, this metric loves joakim, who seems to be out of position consistently when compared to rose.
3
damn what happened to Klay?
2
How about DPoY candidate Avery Bradley? He should be staying next in that chart
2
Bradley has never fared well with most defensive advanced stats, while doing very well in the eye test from players scouts etc. No stat has gotten a really good grasp of on ball defense yet, which is his (and Klay's) strength. Plus guys who get sent to cover the better guard to cover a weak defensive point guard (both AB and Klay do) tend to look worse because they get the tough call every time.
1
My theory is that only 2.9 drb, 0.6 stl, 0.2 blk could be doing more damage than it appears. He always looks like he is doing a solid job staying in front of his man but hardly ever really makes plays happen.
2
DRPM struggles with diminishing returns and over-attributes the success of his lineups to Steph Curry, Kevin Durant, and Draymond Green due to the prior.
Plus he's not an elite defender, just a good one.
1
This is based on ESPN's "real plus minus" and the fact that it is showing Klay Thompson as giving up the second most points this season with his defense shows that this metric can't be used to say whether someone is or is not a good defender. Anyone who thinks Klay Thompson is a poor defender doesn't know basketball. He is an above average defender who guard multiple positions.
But if you want to see how good ESPN's RPM stat is take a look at their rankings of guys and see if it makes sense to you. Some do, some do not.
0
[deleted]
-1†
Funny thing about Knight's defensive numbers is that he's backing up Booker, not exactly the league's premier perimeter defender.
1
Is the chart saying that Lillard has cost his team 32 points in 19 games or 32 points per game?
1
total points this season, so 32 in 19 games.
1
Is that really that bad? I think I'm misunderstanding what this is getting at.
2
yeah i want to know how the "estimate" was derived. it seems like an imitation of DBPM or a comparison to an "average" defender, so like lillard has net -32 / -1.68 ppg vs average defenders. but then why not just use DBPM (which is per possession and probably more accurate)? like -1.68 ppg given up on defense from lillard does not sound accurate at all
1
It should just be DRPM * Possessions/100. In theory DRPM is marginal points per 100 possessions relative to league average..
1
Interesting to me that these are mostly PGs, and not a big in sight. The traditional narrative has been that PG defense is less impactful and therefore less important - it would follow from that that you would see fewer guards on this list than bigs.
I wonder how well this captures secondary breakdown effects where bad perimeter defense gets a bucket after 3-4 rotations.
1
The traditional narrative has been that PG defense is less impactful and therefore less important - it would follow from that that you would see fewer guards on this list than bigs.
Not at all. PGs are allowed to be bad defenders more than bigs.
1
That's partly cheating -- the DRPM prior contains height straight up. Which is dishonest stats work and a great way to introduce bias into the system.
1
Thibs
0
Yikes Portland. Lillard, Crabbe, and Turner