IT: Dead Last in DRPM

[ConstableGeneva]

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[Vee-Rex]

I love stats and find that I am learning more and more. Isaiah Thomas's DRPM is not good, but it's important to understand what kind a value a player brings in spite of that. RPM is ESPN's ultimate impact machine and the general populace does not know the formula(s) involved with it. But there are inconsistencies, and an individual's RPM or DRPM does seem to include the impact of teammates despite promising that it doesn't do that.

You can take a look at the wildly fluctuating RPMs of Trevor Ariza. At 33 years old (off the top of my head), I don't think he's suddenly a much much improved player this year than in seasons past. But the Rockets have surprised the league and have been a top 5-6 team for awhile now.

Look at Maurice Speights. His RPM has sky-rocketed. Is he a better player this year than the last few? I highly doubt it. But his new role with the Clippers, who have a different system is probably a big factor in his RPM being higher than when he was practically dead weight on a 73-win Warriors team.

RPM works as a predicative manner as well. It uses the past performances of players to try to predict how they should be playing (the more consistent the player, the better). Guys like CP3 and LeBron will probably post high RPMs for awhile even if their regular season play doesn't totally reflect it.

A team's schemes, players, and rotations have a lot to do with everything. If RPM is indeed factoring in the performances of teammates and league averages, then it's not surprising that Isaiah Thomas has a low DRPM while playing with defensive beasts in AB, Crowder, and Smart. Most PGs would have terrible defensive plus/minus stats while playing with those guys, and while DRPM promises to account for that, there's plenty of examples (like the couple I showed above) that seem to argue otherwise.

SportVu tracking shows that IT doesn't do well in man-to-man defense, but it's not AS bad as you may expect. Currently, guys are shooting an overall +2.0% against IT than they do their regular FG%. If they are normally 50% from the field, they shoot 52% on IT. With 2-pointers, IT's man is shooting a +4.5% on him. Where they shoot 50% from 2-pointers, they shoot 54.5% on IT. In the paint, guys are shooting a +13.4% on IT than their norms. If they're regularly 60% in the paint, they're 73.4% with IT guarding them.

That last one isn't a big deal. IT is super short and if he gets switched onto a big man or if a big man grabs a rebound with IT guarding him, they SHOULD have a big increase with FG% in the paint versus him. That's fine and to be expected. The interesting bit is this:

At the 3-point line, IT is making his man shoot a -1.8% differential. If they normally shoot 40% from 3-point range, they shoot 38.2% when IT is guarding him. That's GOOD.

I guess my point is this - IT has been an offensive juggernaut, and while his defensive stats overall have been poor, there's other factors that are also involved. Anyone who spouts off that IT is a net negative (because of on/off numbers - which btw are complete trash without context and years worth of data) is blindly babbling about on/off numbers without a full understanding of how they work and what they mean. Without even counting the fact that individual offense naturally outweighs individual defense (that's another topic for discussion that I'd happily debate), you can see what IT brings to this Celtics team.

There are aspects of his game that can't even be SPECIFICALLY quantified for - such as leadership and passion. Stats, both traditional and advanced, are there for information. But the conclusions we draw from them are on US, and the lack of logic and context (which happens far too often) will have people making some ridiculous statements - like suggesting the Celtics are better with IT off the floor.

[Vee-Rex]

Haven't read through the thread but looking at the DRPM of PG's I notice:

- only 18 / 86 point guards are listed with a positive DRPM, while 68/86 are listed as negative. It should be much closer to a 43/43 split if 0 is league average. 79% of point guards can't be below average defenders cus logic
- Ish Smith is the 9th best defensive point guard, Fred VanVleet the 10th, Lin the 13th, Curry the 16th, Rondo the 18th

There's a lot of noise in that list and I don't know how much stock I would put in it. That said, it's obvious IT is a negative on D, not debating that. Just not a huge fan on blanket stats especially defensive ones.

Ha, this is great information.

7 of the top 8 EC teams have aggressive, scoring point guards (some are good at passing, etc... but scoring is a strength for them). 11 of the 15 EC teams have it. The league as a whole have a lot of point guards that are like this compared to years past. This tells me that guys like IT have their hands full, especially when they must also carry the team's offense. While I'm sure every Boston fan wants him to do better on defense, it's hard to harshly judge the guy given his workload and stature.

It also shows how amazing guys like CP3 are but that's besides the point.

[jfs1000d]

DRPM makes no sense.

Someone came up with a formula, and then went out there and didn't validate it.

Stats have to align with other variables. Garbage in and garbage out.




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[FlatearthZorro]

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Basically what I have been saying. IT ain't a great defender, but we were a great defense with him last season. This season our defense took a dip(rebounding, opponent 3 pt % etc) so did IT's stats on D. It's pretty simple.

[OFWGKTA]

Interesting read on RPM:

This has a number of implications. One is that RPM tends to be skeptical of player improvements (or regressions) that exceed what is expected for a player that age. This season, Anthony Davis improved much faster than most 20-21 year old playes. People who watch basketball know that Davis is super talented and accelerated growth is expected from him. However, Real Plus-Minus doesn’t understand this and suspects that Davis’ numbers might be a random blip. As a result, Real Plus-Minus is liable to underestimate Davis’s impact this season9.

On a less technical note, RPM’s focus on prediction makes it a poor way to determine who should get end-of-season awards. I think this is an important point to emphasize because ESPN does exactly this in its introduction to RPM, using it to argue that Taj Gibson is a better candidate than Jamal Crawford for 6th Man of the Year. RPM is optimized to predict the future, not evaluate the past.

Let’s look at James Harden. The Beard is regarded as a great offensive player, and his ORPM of 5.69 (fourth-best in the league) bears this out. He’s also viewed as a laughably poor defender, which is confirmed by his DRPM of -2.66 (77th out of 91 shooting guards). When we analyze the components of his game, his numbers agree with the eye-test.

However, this doesn’t hold up when we consider his game as a whole. Many analysts and fans consider Harden to be a top-10 player. But RPM ranks him 46th overall, just ahead of Robin Lopez. What gives?

This discrepancy exists because Real Plus-Minus forces us to weight Harden’s offense and defense equally. A subjective evaluation of his game makes it easy to focus on all the great things he does on offense and forgive his shortcomings on the other end. I found myself surprised by how low he ranked, but after thinking about it, I have to agree. In order to think Harden is a top-10 player, you must believe one of the following:

1.Harden is close to league average on defense.
2.Harden is significantly better on offense than Chris Paul and Stephen Curry.
3.A point added on offense is worth more than a point added on defense.

I don’t agree with any of these statements, so I’m forced to concede that Harden isn’t a top-10 player.

I’m grouping the next two together because they both deal with how to interpret Real Plus-Minus scores.

Unsurprisingly, different positions tend to be better at different things. Point guards tend to be more focused on offense, while center are more likely to be gifted defenders. This should have an effect on how we value different players.

Let’s consider the following question: Does Roy Hibbert or Paul George contribute more to Indiana’s league-leading defense? DRPM gives Hibbert a rating of 3.52 while George is at 2.61. If you stopped your analysis there, you’d conclude that Hibbert is the key to the Pacers’ stinginess.

However, when you adjust for position, this isn’t the case. An average center has a DRPM of 1.78, while small forwards average a rating of 0.04. Hibbert exceeds his positional average by just 1.74 points per 100, while George does so by an impressive 3.48 points. When we consider position, you can make a compelling argument that George provides more defensive value than Hibbert

https://cornerthreehoops.wordpress.com/2014/04/17/explaining-espns-real-plus-minus/

[DarkAzcura]

So we have gotten to the point where a Cavs fan had to come in here to knock some sense into people?

Spoiler:

mostly kidding..but srsly..

[Dannyboy36]

Words cannot express how much I hate analytic talk. I'm not dismissing it like it doesn't have merit but it just makes me think of baseball. I'm sad analytics has invaded NBA talk on tv so much.
I'll just accept IT is the worst at d. I don't care about seeing a bunch of math. Great on offense, sucks on d. Good enough analysis for me.

[Edug27]

At the end of the day, IT is why we are second in the Eastern Conference right now. He is why we were able to sign a free agent like Horford. Heck, he is why this Celtics team is relevant. We are 30-15 with him in the lineup.

Yes he has big flaws.
Yes he's "worth" the max.
Yes he should be starting.
Yes it does correlate to our defensive woes, but we also have a bunch of other correlations as well.

[CeltsfanSinceBirth]

IT is third in OPRM. I think that ought to count for something.