Yesterday, Jerod wrote a fantastic article on Dirk Nowitzki’s historically efficient night. In his article, he took an idea that was initially launched by Bill Simmons about a stat that measures a player’s efficiency on the offensive side of the ball.
He called the stat Points Per Miss, or PPM.
The stat really speaks for itself. How many points does a player score for every one of his missed shots? Really, it’s determining if a player brings more to the table than he takes from it. Every missed shot is a blown possession for his team while every make is a converted one.
We discovered that Dirk had an outstanding single-game PPM of 16 in Game 1. For every one of his misses, the big fellow scored SIXTEEN points. Simply outstanding.
However, as we thought about the stat more, and took the insightful and analytical contributions of commenters into consideration, we realized a few things.
“Had Dirk missed one more shot, his PPM would be 12. Had he missed 3 more shots, still a respectable 12-18, his PPM would be 8. Since this stat uses division, the numbers cannot be compared linearly. For example, comparing PPMs of 16 and 12 is not the same comparison as PPMs of 6 and 2, even though the difference between each is 4.”
Another thing we realized was that all shots are not created equal. Should a missed free throw count just as much as a missed field goal? Should missed three pointers count as much or more as a missed two-pointer?
Eventually we came to some conclusions about how PPM could be greatly improved.
First of all, missed threes and twos should count the same. Both misses (unless your team gets an offensive rebound) end up costing your team a possession. That’s one more possession where your team could have scored, but didn’t because you failed to convert.
The other question was about free throws. If you miss the first attempt of a two-shot foul, you haven’t necessarily lost your team a possession. In fact, you still get the opportunity to get your team a point. Really, free throws could be thought of as half of a field goal…since you normally get two of them and each shot is worth half of a field goal.
However, sometimes you only get one free throw because you earned an and-one. Other times, you are fouled on a three point attempt and get three freebies. We decided to use John Hollinger’s formula from his advanced statistic True Shooting Percentage to work out the details. He figured out a free throw attempt is worth 0.44 possessions.
That leads us to our final formula for figuring out Points Per Miss, which is slightly different from yesterday but more precise and useful:
PPM = Points / (Field Goals Missed + (0.44 x Free Throws Missed))
Because Dirk didn’t miss a single free throw, his PPM would still have been an outstanding 16. If he had missed one free throw, it would have dropped to 13.95. If he had missed one more field goal, it would have dropped to 12.
Obviously, with such an outstanding game, the results are likely to change A LOT with just one more make or miss.
However, the benefits of PPM are much more relevant when looking at someone’s season or career as a whole.
We will get to that in a second, but first I’ll address what I’m sure some of you are thinking: Wow…these guys have done nothing significant…this is just a ripoff of Hollinger’s True Shooting Percentage.
Let’s compare the two and discuss a few main points.
- PPM = Points / (Field Goals Missed + (0.44 x Free Throws Missed))
- True Shooting Percentage = Points / (2 x (FGA + (0.44 x FTA)))
The stats are very similar to say the least.
I believe they are different enough to both be useful, even together.
Percentage vs. Points
For one thing, Hollinger’s TSP gives you a percentage that the player shot from the floor. For instance, Dirk had a 61.2% True Shooting Percentage this year and Paul Pierce had a 62% True Shooting Percentage. With that stat, you get an idea of how well the guy shot from everywhere.
Our stat gives you an idea of how many points that guy scored for every miss. Dirk scored 2.85 points per miss and Pierce scored 2.79.
That difference is small, but it does give you a different sort of figure to compare the two players.
A More Complete Picture
The BIGGER difference I think is that it tells a more complete picture.
Let’s compare those two guys again. If you just looked at TSP, you would assume that Pierce is the more efficient scorer than Dirk, but if you really look at the stats that doesn’t make any sense.
- Pierce averaged 18.9 points, shot 86% from the line, 37% from three, and 50% on all Field Goals.
- Dirk averaged 23 points, shot 89% from the line, 39% from three, and 52% on all Field Goals.
So you have a guy who averaged MORE points and shot a better percentage from ALL THREE areas, but somehow he has a WORSE True Shooting Percentage than the other guy. That’s because True Shooting Percentage rewards players that score a higher percentage of their points from the free throw line. Dirk only scored 23% of his points from the foul line whereas Pierce scored 25% of his points from there this season.
Here is a more clear example.
Let’s pretend that two players both scored 30 points on a given night.
- Player A was 10-20 from the floor and also finished 10-12 from the charity stripe. He missed 12 shots, and ended up with a PPM of 2.757. However, his True Shooting Percentage was 59%.
- Player B was 14-24 from the floor, but only 2-4 from the foul line. He also missed 12 shots, and his PPM remains the same – 2.757. However, HIS True Shooting Percentage dips slightly to 58%.
Just by looking at TSP, the common person would believe that Player A was more efficient. However, that’s not really the case because while Player B did not shoot as well from the foul line, he actually shot BETTER from the field, which actually saved his team more possessions. Both players were equally effective. PPM shows that, TSP doesn’t.
All of that to say this:
I believe that our stat provides a more accurate picture of true efficiency on the offensive end of the floor than True Shooting Percentage.
It shouldn’t really matter where a player is getting his points. Some players score by getting to the free throw line. Other players score remarkably well without getting to the line. We need a stat that measures overall effectiveness correctly, and I believe that PPM helps us to accomplish that goal a little better.
At the end of the day, Dirk and Pierce are both remarkably efficient, and both deserve lots of credit for that. Like Jerod said yesterday, I had no idea Pierce was so efficient, and he now gets a lot more respect from me. But PPM provides a little more accurate picture of true efficiency.
When I look for efficiency, I am really looking for how many points per possession/shot/miss someone averaged. Percentages may lie; PPM doesn’t.
Below is a quick look at the top fifty scorers from the NBA this season, plus Steve Nash…because I’m always interested to see where he finishes in these types of stats.
What you will notice is that the PPM tends to lean a little more towards a) big men who get their shots around the basket and b) lights out shooters. This doesn’t really tell us anything new though, does it? Big men and great shooters are more efficient scorers than slashers and athletes.
A few interesting players of note: Derrick Rose, Kobe Bryant, and Russell Westbrook all fall out of the top ten and into the mid-30s. Meanwhile, Pau Gasol takes an almost meteoric rise up to #4.
Another player who is not on the list is Chris Paul. He ended up with a 2.444 PPM, putting him higher than all point guards not named Steve Nash and Tony Parker. However, his playoff PPM of 3.35 was unbelievable. Anyone who watched him against the Lakers would have said he was remarkably efficient…but good grief!
You can go up and down the list and make your own conclusions. It is fun and, in many cases, quite surprising.
|FGM||FGA||FTM||FTA||Total Points||Missed FGA||Missed FTA||PPM|
Three more things of note.
First of all, no stat is perfect. The danger with all new stats is that we think we have figured out something so good that we no longer need to watch the game to decide how good a player is or is not. No one should look at this stat and decide that Derrick Rose, Kobe Bryant, and Russell Westbrook are bad players. However, it’s not surprising to anyone to see that they really aren’t super efficient on offense.
That’s the thing I love the most about this stat. In my opinion, it really reflects what you see. It’s more of a tangible verification than a new breakthrough. Anyone who has watched the Lakers all year would tell you that Pau is a more efficient scorer than Kobe, but even I didn’t think the difference would be that diverse.
Secondly, I think this stat is still a work in progress as far as what we can learn from it.
I have not had time to find out the league average for PPM yet, but it would be nice to figure that value out so we can really compare players. For instance, if you didn’t know anything about baseball, you would think that someone being successful at the plate only 30% of the time was awful. It isn’t until you realize what everyone is hitting that you understand that hitting .300 is fantastic.
With that said, PPM is still easy to understand because Points Per Miss is about as simplistic as it gets. Everyone who has ever watched basketball can understand that scoring 2.5 points per miss would be outstanding.
The other place this stat could really go is in terms of teamwork. I would be very interested to see how much a player’s presence on the floor affects his teammates’ PPM. Obviously LeBron James made his Cavs teammates more efficient players, but how much so? I believe this could be the next step of PPM.
Finally, I thought this comparison was telling: Reggie Miller’s career PPM was 2.632. Ray Allen’s is a paultry 2.304.
The ball is in your court, SportsGuy.
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