As I alluded to in my last post, something I’ve wanted to do for a long time was to make a player rating system that is totally customizable. Every team has different needs at different times, so the one-number-fits-all style of player rating systems, which has been the norm, seems inappropriate in certain situations. Today I would like to explain to you something I’ve created called the TPS (Talent Plus Style) player rating system (movie reference: when I produce TPS reports in the future, just know that I did see the memo and I won’t forget to include the new cover sheet).
Why TPS? As I said in my last article:
Let’s say Shaquille O’Neal rates better than Rashard Lewis in Player Rating System X. The Magic should try to swap Lewis for Shaq, then, right? Obviously not. Orlando needs a big man (calling Lewis “big” is a stretch, but go along with it for now) that can stretch the floor and give space for Dwight Howard down low. Suddenly, we’re doing so much contextual research for Player Rating System X that the player rating itself isn’t that useful anymore. Instead, we’re relying on shooting percentages, shooting tendencies, rebounding ability, defensive ability, etc.
Having the flexibility to specify what you are looking for in particular from a player makes things easier for talent evaluators and more fun for fans. There are a couple of things about TPS that make it very useful:
Which variables can be included in TPS player ratings? They can be broken down into three categories:
Composite Score Stats:
Shooting Stats:
Other Advanced Stats:
As you can see, I did not develop all of these statistics (for some I just adjusted them for position and use them as components in my ratings). Offensive and Defensive Ratings were developed by Dean Oliver and can be found at Basketball-Reference.com. PER and many of the other advanced stats were developed by John Hollinger. I used Basketball-Reference and Knickerblogger.net to gather these. For player names and teams, I used Dougstats.com. For positions, plus-minus, and Counterpart PER, I used 82games.com. Additionally, although I calculated the shooting stats myself, similar numbers can be found at 82games. To calculate the shooting stats, I used the play-by-play data available at BasketballValue.com.
The ratings I have come up with so far are all based on a 0-100 scale, with 50 being average. Remember that these ratings are adjusted for position, so a player with a 50 is average for his position.
To give an example of what TPS can do, I have created a rating called Playmaker Score. This number rates players on all of their abilities, but especially their ability to create shots for others. It considers a player’s Composite Score, Assisted Rate, Pure Point Rating, and Assist Rate (remember that Assisted Rate measures how many of a player’s shots were assisted by others while Assist Rate estimates how many of teammates’ field goals an individual player assists on). To see the numbers, go to:
Link
This is just one rating that I threw together pretty quickly. Still, it gives some interesting results and shows what TPS is capable of doing. Over the next few weeks, I will come out with some similar player ratings using TPS. If you have any questions or suggestions, feel free to comment below.
P.S. If you’re wondering what movie I referenced earlier, check out: Link to video
One concern that many people have is that player rating systems are often too general. I’ll be the first to tell you my Composite Score rating system needs a bunch of contextual information to truly be useful. It’s simply too hard to sum up all of a player’s abilities with a single number. One major problem is all the things that go unmeasured, although that’s outside the scope of our abilities until we start tracking new things.
A second major problem, one that I’m trying to find a solution for, is that different teams have different needs for different situations. Let’s say Shaquille O’Neal rates better than Rashard Lewis in Player Rating System X. The Magic should try to swap Lewis for Shaq, then, right? Obviously not. Orlando needs a big man (calling Lewis “big” is a stretch, but go along with it for now) that can stretch the floor and give space for Dwight Howard down low. Suddenly, we’re doing so much contextual research for Player Rating System X that the player rating itself isn’t that useful anymore. Instead, we’re relying on shooting percentages, shooting tendencies, rebounding ability, defensive ability, etc.
It still would be nice to have one number when we’re trying to evaluate players, if for no other reason than to save time. But we’ve already proven that one number is useless without context. What can we do?
Create multiple sets of player ratings. Better yet, create an organic player rating system that adjusts based on whatever is important to us at the moment. The Magic need a power forward that can shoot three-pointers efficiently and create his own shot from time to time? Ok, let’s rate power forwards based on that.
The next step is to calculate all of those little components and adjust them by position. Why adjust for position? If we made a player rating system based on three-point shooting ability and shot-creation alone, without adjusting for position, our numbers would tell us the Magic should acquire someone like Roger Mason and put him at power forward. That doesn’t seem like a wise suggestion.
Once we have all the position-adjusted components, we can then decide which are important based on our needs. Today is the first step. Similar to how I broke down individual players by quarter, each player in the league will be rated based on how he performs from four shooting locations: close (dunks and layups), midrange (including post shots), three-pointers, and getting to the free throw line. Each rating is adjusted for position, so a center with a 90 rating on three-pointers is still very likely worse overall than a shooting guard with an 80.
The ratings will combine both frequency and efficiency. In other words, if a player rarely shoots from midrange but is efficient at it, he won’t rate that well. Similarly, if he shoots from midrange all the time but is highly inefficient, he also won’t rate well. Ratings are on a scale of 1 to 100, with 50 being average for that position.
Frequency is measured by the player’s attempts from that shot location divided by his total attempts. Efficiency is measured by his makes divided by his total attempts from that location. The only situation that is included in this efficiency measure is when a shot actually goes up, so things like turnovers are ignored.
Before I release the numbers, I should say that these shooting tendencies and efficiencies are nothing new. 82games.com has had this data available for a while now. My methods for extracting these tendencies and efficiencies from the play-by-play data are slightly different, but they are similar. The new step I am taking is adjusting these numbers by position and creating a rating system off of these adjustments. The numbers are available through Google Docs below:
http://spreadsheets.google.com/ccc?key=0AvNKNGJ_AHijdE5RWnZVcG9vS1VaQ1B5VFdBZG5tMHc&hl=en
If you’re angry because a certain player does not rate the way you’d expect, allow me to explain. First, remember these ratings account for efficiency. Superstars may be excellent shot producers (a skill I will rate in the near future), but they are not always the most efficient. Second, these ratings also account for a player’s tendencies. If a player is extremely likely to take a certain shot, his rating will be high for that. However, if he balances his shot attempts, he will not rate extremely high in any of them.
A simple way to look at it is that these ratings are attempting to describe players as much as they are attempting to evaluate them. LeBron James may only get an 80 in close shots (which is still quite high), but that’s because he mixes up his attempts. He clearly is one of the most frightening players in the world when he’s near the basket.
These ratings do evaluate to an extent, but the bulk of evaluation for my new rating system will come from other components. Shooting ratings will be a big part of the context I mentioned at the beginning of this article.
This is just a first run, so changes will inevitably be made. If you have any suggestions, feel free to comment below.
If you’ve been reading Basketball-Statistics.com over the last few weeks, you know that I’ve been examining the individual shot selection of a number of the game’s superstars using the play-by-play data at BasketballValue. So far, I’ve taken a look at LeBron James, Dwyane Wade, and Kobe Bryant. How different will the results be when we take a look at a big man such as Dwight Howard? Let’s take a look:
There are two changes from last time: three-pointers are not included (for obvious reasons), and as we will see later, I included the efficiency of trips to the free throw line to go along with the efficiencies of shots from the field.
With Howard, we can see that he generally favors dunks/layups (not a bad choice). His frequency of those attempts dips a bit in the fourth quarter, but it generally stays about the same. Midrange/post shots (presumably mostly post) start equal with close attempts but decrease considerably as the game goes on. Where are those shots going? To the free throw line. In the first quarter, Howard ends up at the free throw line on only 23% of his possessions, but by the fourth quarter that number has nearly doubled. In fact, it is how he does most of his damage late in the game. Are the last two trends I mentioned smart decisions by Howard or do they work in the opposing team’s favor? Let’s take a look at the efficiencies of the three shot types:
First of all, his shooting percentages do not change much as the game goes on. There are slight changes in each shot type, but they don’t seem very significant. However, this graph does confirm one thing: Howard is much more efficient by getting to the line (despite his poor free throw percentage) than he is by taking shots from the midrange/post. The latter is an area in which he continues to improve, but like most players it is still his least efficient shot by far.
Up next, I’ll take a look at another superstar big man and see how he stacks up to Howard.
First was LeBron James. Next was Dwyane Wade. Today I’ll be looking at the shooting tendencies of Kobe Bryant. My methods will be the same as with the first two, so if you have any questions about how or why I do certain things, be sure to check out those first two articles.
Here are Bryant’s shooting tendencies by quarter:
If you read my pieces about James and Wade, the first thing you’ll notice is that Bryant takes a lot more midrange shots and much fewer close shots than the other two. However, he does have one thing in common: as the game goes on, Kobe favors the three-ball more and more. Those shots make up just 11% of his attempts in the first quarter, but they double to 22% by the fourth. However, unlike the other two, these attempts do not come at the expense of close shots. Close shots do go down slightly, but Kobe also seems to make a concerted effort to get to the line as the game wears on, especially in the fourth quarter. Instead, Bryant chooses to forgo midrange shots (which is a smart decision, as we will see later).
Why is Bryant more relentless at taking it to the basket than James and Wade? Part of it could be a personal mentality, and part of it could be less fatigue. After all, the Lakers can offer much more offensive support for their superstar than the Cavaliers or the Heat. Whatever the reasons, Bryant is able to take more efficient shots (three-pointers) in the fourth than he does in the first.
How about his efficiency on those shots? Let’s take a look:
Like most players, Bryant has his ups and downs. However, I see three general trends: midrange efficiency decreases slightly, close efficiency increases slightly, and three-point efficiency peaks in the middle of the game. Still, at all times Bryant is more efficient from three than he is from midrange, so his shot selection trends seem to be wise decisions.
I’d like to keep looking at individual players, but I may switch gears and look at a big man next. The results may be drastically different, so stay tuned.
As a follow-up on my piece on LeBron James, I’ve decided to take a look at another superstar: Dwyane Wade. Like James, Wade is a prolific scorer who makes his living close to the basket. How does Wade change his offensive style as the game goes on? Let’s take a look:
As you can see, I made one change from last time. For Wade, I included offensive possessions that resulted in him taking shots from the free throw line. The reason for this is that close shots might be underestimated because of the frequency that forays into the paint lead to fouls.
Like James, as the game goes on, Wade increases his attempts from beyond the arc at the expense of close shots and a bit of midrange. Even if we assume every trip to the line came off a close attempt (which would be very questionable, especially considering non-shooting fouls that occur after the opposing team is over the limit), the trend is still the same. In the fourth quarter, Wade takes almost three times as many three-pointers as he does in the first. Like I suggested with LeBron, fatigue could be a factor, as could adjustments made by the opposing defense.
The bigger question may be: are these adjustments by Wade justified? Let’s take a look at the efficiencies of three’s, midrange, and close shots for Wade:
Here we see a major difference between Wade and James. While the latter gets worse on three-pointers as the game goes on, the former gets better. Remember, that was the major concern with James. Despite it becoming a less efficient shot for him, James favors the three-pointer more and more as time elapses. Wade gets much more accurate from long range, while his efficiencies in the other two shot types decrease slightly. This means his increase in three-point attempts makes more sense. In fact, Wade is a pretty darn good three-point shooter in the third quarter.
Can we try to optimize the shot selection for an NBA player? Nobody knows how to balance a player’s offensive game better than the player himself, so I don’t think we should try. Still, we see that LeBron’s in-game adjustments don’t seem to make sense like Wade’s do. Whatever the reasons, it appears the Heat do not suffer to the same extent as the Cavaliers (based on the individual performances of Wade and James alone).
