Measure of Efficiency... PPS or TS%?

[italianleather]

Are PPS and TS% representing the same thing, just presented differently?

If not, what is the difference & which parameter projects efficiency better?

[Doctor MJ]

Both are meant to really show the same thing - however PPS is a horribly flawed simplification.

PPS is literally points divided by field goals attempted. It doesn't factor in the shots a player take that result in two/three free throws.

TS% attempts to estimate hoe many shots a player has actually shot, and divides points by that. The formula is Points / (FGA + (.44 * FTA)) / 2.

It should be noted that TS% isn't perfect either. That coefficient .44 is based on the average correlation of free throws to shots taken that don't get counted as field goal attempts. Obviously a better stat would be based on scorekeepers actually recording the number of shots taken. That scorekeeping throughout the ages has chosen not to do this is very frustrating, and completely wrongheaded. However, it's the best thing we have for a 1 stat estimation of shooting efficiency.

[kabstah]

The thing that bothers me most about TS% is that if you make if you miss the free throw on an AND 1, that makes you less efficient than had you not drawn the AND 1 on the made shot in the first place. To that end, it probably underestimates the efficiency of someone like Shaq, who was excellent from the field, terrible from the line, and drew a lot of AND 1'S. I also have no idea what the significance of dividing by 2 is, besides ensuring that the TS %'s fall below 1.000, although it's still technically possible to get a TS% above that if you only shot 3 pointers and made them at a clip greater than 2 out of 3.

Like the Doc says, however, it's the best all-in-one scoring efficiency metric we have at the moment.

[Doctor MJ]

The thing that bothers me most about TS% is that if you make if you miss the free throw on an AND 1, that makes you less efficient than had you not drawn the AND 1 on the made shot in the first place. To that end, it probably underestimates the efficiency of someone like Shaq, who was excellent from the field, terrible from the line, and drew a lot of AND 1'S. I also have no idea what the significance of dividing by 2 is, besides ensuring that the TS %'s fall below 1.000, although it's still technically possible to get a TS% above that if you only shot 3 pointers and made them at a clip greater than 2 out of 3.

Like the Doc says, however, it's the best all-in-one scoring efficiency metric we have at the moment.

Dividing by two keeps it roughly in line with FG%. A guy who shoots only 2's, and doesn't go to the free throw line will have identical TS% & FG%. Because everyone's used to thinking in terms of FG%, the adjustment is made to make the new stat more intuitive.

As far as who is overrated and who is underrated by the stat, I have a hard time even guessing. Clearly, if you're prone to make shots when you get fouled, then you may be underrated. On the other hand, if you're prone to being intentionally fouled both before you can really get your shot off or even before you even have the ball because you suck so badly at it, you may be very much overrated by the stat.

[mopper8]

As far as who is overrated and who is underrated by the stat, I have a hard time even guessing. Clearly, if you're prone to make shots when you get fouled, then you may be underrated. On the other hand, if you're prone to being intentionally fouled both before you can really get your shot off or even before you even have the ball because you suck so badly at it, you may be very much overrated by the stat.

I think the stat overrates players who score efficiently when they do attempt to score, but also are poor at ball movement/break off plays/etc and avoid taking low efficiency shots after doing those things by simply passing to someone else and making that player take the low efficiency shot. Corey Maggette, for example, used to be guilty of this (and still may be, for that matter).

[DeeDub]

As far as who is overrated and who is underrated by the stat, I have a hard time even guessing. Clearly, if you're prone to make shots when you get fouled, then you may be underrated. On the other hand, if you're prone to being intentionally fouled both before you can really get your shot off or even before you even have the ball because you suck so badly at it, you may be very much overrated by the stat.

I think the stat overrates players who score efficiently when they do attempt to score, but also are poor at ball movement/break off plays/etc and avoid taking low efficiency shots after doing those things by simply passing to someone else and making that player take the low efficiency shot. Corey Maggette, for example, used to be guilty of this (and still may be, for that matter).

That got me thinking a little and made me look at 82games.com's shot clock usage charts. Magette took 7% of his shots int he last 3 seconds of the shot clock and his eFG% on those was .458. By comparison, Wade took 11% of his shots at the end of the clock with an EFG% of .419. Kobe took 14% of his shots late in the clock, with an eFG% of .496. Some of that could be due to what you are saying, but I suspect it has more to do with (1) the fact that Wade was a much bigger proportion of his team's offense in general, and (2) the Warriors play a very high pace game in which they rarely run the clock down, while the Heat played a much slower, defensive oriented pace. Magette's .458 on those late shots is pretty solid though.

Strikingly, LeBron took an amazing 24% of his shots in those last 3 seconds, with an eFG% on those of .477. That 24% is more than twice as high as Wade's and almost twice as high as Kobe's. Almost all players will be less efficient at the end of the clock than earlier. One of the big benefits of the Heat's Big 3 may be eliminating a lot of those forced late clock shots, thus making 3 very efficient offensive players even more efficient.

[Doctor MJ]

I think the stat overrates players who score efficiently when they do attempt to score, but also are poor at ball movement/break off plays/etc and avoid taking low efficiency shots after doing those things by simply passing to someone else and making that player take the low efficiency shot. Corey Maggette, for example, used to be guilty of this (and still may be, for that matter).

Ah, well that's not so much an issue with TS% as it is with using shooting efficiency at all as the measure for the net value a player contributes when he looks to score. You're quite right though, by no means would I rate scorers simply on volume/efficiency.

[mopper8]

I think the stat overrates players who score efficiently when they do attempt to score, but also are poor at ball movement/break off plays/etc and avoid taking low efficiency shots after doing those things by simply passing to someone else and making that player take the low efficiency shot. Corey Maggette, for example, used to be guilty of this (and still may be, for that matter).

Ah, well that's not so much an issue with TS% as it is with using shooting efficiency at all as the measure for the net value a player contributes when he looks to score. You're quite right though, by no means would I rate scorers simply on volume/efficiency.

This true, so I guess I should restate that: people often overrate players based on TS% because they mistake it for rating the net value a player contributes when he looks to score.

[ElGee]

I think that's called "Dantleying."

[mopper8]

As an aside, since I mentioned Corey Maggette and offensive inefficiency, one of my favorites: http://www.youtube.com/watch?v=xN_ljDfevB0

[Doctor MJ]

As an aside, since I mentioned Corey Maggette and offensive inefficiency, one of my favorites: http://www.youtube.com/watch?v=xN_ljDfevB0

Always hilarious to watch.

Discouraging though. This isn't about a ref purposefully refusing to ever call traveling. This is a ref, trained to be a ref and have an observant eye for these type of things, being unable to call basic things even when they are incredibly blatant.

[Doctor MJ]

I think that's called "Dantleying."

I'm beginning to think "Wilting" might be an equally appropriate term, with the benefit of a good double meaning. "The offense Wilted in the 2nd half under intense defensive pressure".

[tsherkin]

As an aside, since I mentioned Corey Maggette and offensive inefficiency, one of my favorites: http://www.youtube.com/watch?v=xN_ljDfevB0

Always hilarious to watch.

Discouraging though. This isn't about a ref purposefully refusing to ever call traveling. This is a ref, trained to be a ref and have an observant eye for these type of things, being unable to call basic things even when they are incredibly blatant.

It should be mentioned that refs miss traveling all the time because they're looking for the foul when a guy is driving. I didn't watch the video, so I don't know if that's applicable, but it is a generally-true comment.

[Doctor MJ]

As an aside, since I mentioned Corey Maggette and offensive inefficiency, one of my favorites: http://www.youtube.com/watch?v=xN_ljDfevB0

Always hilarious to watch.

Discouraging though. This isn't about a ref purposefully refusing to ever call traveling. This is a ref, trained to be a ref and have an observant eye for these type of things, being unable to call basic things even when they are incredibly blatant.

It should be mentioned that refs miss traveling all the time because they're looking for the foul when a guy is driving. I didn't watch the video, so I don't know if that's applicable, but it is a generally-true comment.

Yup, clearly what's happening here is that the ref is looking for other things - Maggette actually eventually ends up called for a foul on the play. That you miss subtle calls when looking for some more likely calls is absolutely understandable. The discouraging part is that this wasn't at all subtle. Maggette traveled 6 times on the play by pivoting and re-pivoting and got away with it. When it's that bad, you'd sure hope that refs would be skilled enough that the rule breaking would hope salient in the refs vision - and it doesn't.

I'd say the most disturbing thing of all to me is that if it's simply ingrained in Maggette's head that he has to keep one pivot foot or else he's probably going to be caught, I doubt he ever makes use of a half dozen pivots at once. That he's playing like that sure seems to me to indicate that this isn't an anomaly.

[tsherkin]

Vince, and just about every other American wing player, gets away with a travel on almost every possession up at the 3-point line. Know the one I'm talking about?

Get it on one pivot foot inside the arc, step, opposite pivot, step, and they're in triple-threat behind the line?

Pisses me off every time.

[meir34]

Re: These Measures of efficiency are weak and gross indicators at best. Yet Hollinger uses them to totally blast away certain players like Monta Ellis.

First of all key variables are left out of the equation. To wit: Is the player being double teamed or more at the time of the shot? Is the starter or a sub doing the defending? What part of the game are the shots taken in, garbage time often is nearer to Summer League than regular NBA play. And many more this is just an example..

But there is a deeper methodological question. Anyone can make up an index and say it measures whatever they can find people to believe that it does. But in science there is an independent judgement, does it measure what it purports to measure. For example the Stanford Binet IQ test, was used to predict success in college. That could be independently judged in terms of interoperative correlation. Take scores and correlate them with grades in college of the subjects.

Here there is simply an index presented and as if derived on Mt.Sinai from G-d, it is accepted or argued. Second there is such a thing as Face Validity, does it appear to measure what it purports to on the basis of simple observation.

When scores reveal 14 players more efficient shooters than Kobe Bryant, one has to wonder. A look at some of those names above him is even more revealing.

What kinds of intercorrelations might be made? There are measures such as rankings on the all pro voting, but that's all around play. Okay, have a panel of however many "experts" select the shooters primarily, like say Carmelo Anthony, and rank those according to votes for League MVP or all star or whatever. Or take salaries, or a new panel of ranking of most efficent shooters and correlate their scores on PER or TS with their ranking on the panel rankings.

My guess from a lifetime of working with social (human) data is that the correlations wouldn't be very high. For any who don't know how to interpret correlations, simply put it is a measure of covariation, or in ranked order data, joint occurrence. For a rough estimate of how valuable the indicator you are using is, take the rough number given (it is expressed in a range of -1 to +1), round it off, and square it and express the first two digits to the left of the decimal point as a percentage. That's the percentage of variation in the dependent variable (what you are trying to predict) explained by the independent varaiable(s) (what you say will predict it, or in experimental circumstances some use cause for independent variable, though that kind of thinking is out of vogue now because of the multiplicity of variables that most things require for accurate explanations, as well as possible simple errors of order of occurrence. So if you have an index that correlates with some measure of the hypothesized dependent variables of say .63, round it off to .6, square it and express that as a percentage, you get 36 percent of the variation in say the ranking by votes for MVP or All Pro is explained by your index. Another way to look at it is that 64% of that variation isn't explained by the independent variable, here PPS or TS%. Hollinger NEVER correlates his scores with anything. In short it is bull bleep worth only what the people he tries to sell it to will pay.

[Chicago76]

Meir34,
I don't think anyone purports either measure to be the end all-be all of efficiency metrics. It's just the best of what is easily quantifiable using box score data. Like you said, it doesn't measure degee of difficulty of the shots taken, but that opens up a whole other can of worms:

-How do you define difficulty? Location? What about the quality of defender guarding me on that shot? What about whether I'm shooter a leaner, or a fadeaway, or standard jump shot? How close is the defender to me? Is this mop up time when no one really cares, or is it a shot with the game on the line when everyone knows I'm getting the basketball?

-Even if you could accurately account for all of these things to come up with something better, what does it tell you? Maybe my eFG is 44%, but my degree of difficulty adjusted eFG is 53%. Does this mean I am an underrated shooter or does it mean that I take really poor shots when I should be passing?

[Chicago76]

Get it on one pivot foot inside the arc, step, opposite pivot, step, and they're in triple-threat behind the line?

Pisses me off every time.

I can't stand this at all either. It's gotten to the point where I can live with the quick shuffle Miller used to do to get set behind he line. If they can't call a very deliberate double pivot where players move several feet, then I'm now willing to accept the 18 inch shuffle, re-set behind the line trick.

[Dr Positivity]

Nice first post, meir34.

Here's a post I made back in July I still believe in

I think I'm going to stop using TS%, for the most part. Here's why: I believe combining stats does us a disservice. My level of belief in a stat comes down to variables. The more variables that go into a stat, the less I trust it. Of course this is because we don't know which of the variables led to the conclusion. TS% has a handful of variables. It takes 2 point efficiency, 3 point efficiency, FT line efficiency, and the level of defensive pressure placed on the player and how 'hard' the shot he's taking. There's also the question of late shotclock and end of the half heaves that could alter the numbers. If all we had was the TS% numbers, we would have no idea how the player got there. Now we can look at the particular 2, 3, FT% stats aside from the TS% and more or less put together exactly how a player came to that overall efficiency. But this doesn't have anything to do with TS%. We could look at the particulars without it. These particulars have less variables, generally 3 FG% percentage for example comes down to the player and the team guarding him, and over the course of a season that latter one shouldn't have a big impact. In the rare case of playing in a system like the Phoenix Suns, that could also boost numbers.

The analogy I use is this. As staticians, our job is to take the game at its surface and zoom in with a microscope. The first zoom level is ppg, rpg, apg, bpg basic stats. You zoom more and you get some of our combined stats like TS%, PER, WS. You zoom in on the TS% and you can see what makes IT up: 2, 3, FT efficiency, and the defensive pressure and heaves stats we can't measure (yet). So to me taking those particular stats and combining it into TS% is actually going BACKWARDS in the microscope zoom. It simplifys the stats, when I believe IMO looking at the stats more broken apart and deeper in, is more valuable. A players' raw TS% does not tell us as much as looking at his 2 point, 3 point, and FT numbers. Those particulars tell us much more about what the player is effective at. We should be able to piece together on our own that a player who gets a lot of points from the FT line at a good percentage, while shooting a high number from 2 and a high number from 3, should be one of the league's best scoring options. TS% tries to simplify all shooting efficiency into one number, but why should we want that? There are so many different types of shots and scoring attempts that measuring it all by the same stat is doing us a disservice because it tells us less instead of more.

I believe we should have more stats, not less. I'm going to start emailing basketball-reference to include raw 2P% on their page, frankly it's embarrasing they don't have it, it'd be the easiest thing in the world to calculate and one of their most important basic stats. But in the future I think the most important new stats will be stuff like "20 feet jumper %", "Within 5 feet of the basket %", differentiating between open and contested 3s, and of course, defensive stats. These are the next step inward on the microscope zoom. Combining stats just doesn't interest me much because the only basis for it is coming up with quickfire arguments and making our knowledge of the game less complex

I feel the same way about baseball and OPS btw. OPS and I have always got on the wrong foot because there's no theoeretical basis for it to adding together OBP and SLG to me. It's pretty obvious they're not exactly equal. It'd be like adding together ppg, apg, and rpg and using it as the ultimate basketball evaluator. Maybe if they had a multiplication equation for it, that would make sense. Every time you get on base, * it by SLG. But the most obvious solution by far is just to forgo the laziness and talk about them separately. OBP makes sense, SLG makes sense, instead of combining them which doesn't make sense, just use 2 separate tools to evaluate a players batting. But w/e.

One note, my microscope analogy in the 2nd paragaph is set up wrong. Technically the "top" and most indistinguishable level is the PER and WS, then you zoom in on them to get ppg, rpg, apg, TS%, etc. which makes it up, then you zoom in on TS% to find where that efficiency came from. Nevertheless the point is the same. We can learn more from considering 2P, 3P, FT line scoring separately than we can from the all together, indistinguishable TS%

And I still think OPS is no more valuable than PER. Gives us a ballpark estimate of the best players, but judging players like Hamilton and Carbera against each other by decimal separation with such a flawed equation makes as much sense as saying "Player A has a 27 PER, Player B has 26, Player A is better"

[tsherkin]

You're basically talking about the data Hoop Data provides in that post.

TS still has value, it just requires context. You need to know shot volume and you need to know minutes and player role, but it provides a useful snapshot of a player's efficiency. A below-average TS is a bad thing, always; if you're under league-average, you need to be called upon to create your own shot less frequently, period. If you're around league average, you're probably not a great option for volume production. If you're above league-average, you're doing OK.

How you get there (FTAs, 3P shooting, high FG%, w/e) isn't so important, but there's a pretty clear trend where elite scorers tend to be at or above 55% TS if they're reasonably healthy. It's when you start getting picky about what the player is doing, how he could improve, how he could be defended, etc, etc, that's when the specifics of his scoring approach become relevant. How much is he assisted? What's league-average Assisted% at 10-15 feet for forwards? That kind of data becomes important.

TS% is still more useful than raw FG%, but like any stat, it requires accompanying context. It's well and good to say a player shoots 48% from 16-23 feet, but if he's taking 25% of his shots from there and still posting a TS of 49%, then he bloody sucks and is inefficient, and is a tool. TS% will effectively highlight that, regardless of how good a shooter he is above the foul line.

Meantime, the relevant components of TS are basically FTA/FGA, 3P%, FT%, and the various levels of FG% relating to the different zones on the floor (at the rim, < 10', 10-15', 16-23'). That data IS available.

It's mostly also called the Four Factors, and isn't new. Dean Oliver has been using eFG% (which accounts for 3P%), FTM/FGA (which accounts for FT% and DrawF), OREB% and TOV% to create an image of a player/team offensively for years now. FF analysis is pretty standard stuff off of RealGM.