why you do not want to be stuck in the middle

Hi everybody,
just a quickie. Hope it speaks for itself.
Seth Partnow (I'm never sure if that's a spelling mistake), collected some data https://t.co/3hrprry8vR
It's pretty awesome, because it means that I can make interesting plots without an hour-long copy and paste job. Just ask if you feel like looking at a certain aspect of the data.
Back to Morey ball: Morey ball tells us that it makes sense to shot only from the rim or from behind the three point line if possible (sounds intuitive? Ask Byron Scott).
Short side note: I'll try to post something longer about this topic, as it is not as simple as it sounds to get open shots at the rim or from three point land (duh)
Interestingly, there is even a positive correlation for the Morey Ball shots (more shots from 3 or rim means higher effective field goal percentage from there) and a negative correlation for midrange shots (more shots from midrange means lower effective field goal percentage from there). Both with a small but existent correlation of around 0.4 (or -0.4).

Click on me

Cheers,

Hannes

Good cops - bad cops in the NBA

Hi everybody,

just a quicky as I stumbled over plus minus data. There are a lot of adjusted Plus Minus (PM) stats, but the idea is always similar: A players PM is obviously related to a teams point differential. So I took all players that had during the season a PM of more than 100 or less than -100 and plotted their PM per minute against the Team +/- per game. I leave the analysis to you.
Enjoy,
Hannes

All Cops

Why shooting only one free throw would not increase the average value - but slightly change the game

Hi,

just a short one regarding an idea that was first mentioned here:
http://espn.go.com/blog/truehoop/post/_/id/70581/hoopidea-is-one-trip-to-the-free-throw-line-enough
The idea is to change the free throw concept to speed things up. Instead of two free throws that are worth two points, we could as well shoot one free throw worth one point. Or three points, if it's for a three-point foul and so on...
The always amazing Nylon Calculus crew spun it a little further
http://nyloncalculus.com/2014/10/02/shooting-one-free-throw-offense/
calculating that the expected points per free throw attempt would not change (so basically the mean), but the variance would increase (due to less attempts).
My first reaction was to say 'but what about offensive rebounds!? You cannot rebound the first shot!'
This is true, but it doesn't change the math (too bad, I love to be a nitpicker...)

FT% - Free throw percentage of a player
OR% - Offensive rebound percentage
POR - Points we expect after an offensive rebound
Expected points two free throw situation (resulting points multiplied with their probability):
1       *(1-FT%)*FT% +
1       *FT%*(1-FT%)*(1-OR%) +
2       *FT%*FT% +
(1+POR) *FT%*(1-FT%)*OR% +
POR     *(1-FT%)*(1-FT%)*OR%
0       *(1-FT%)*(1-FT%)*(1-OR%)
=2*FT%+OR%*POR-FT%*OR%*POR

Expected points one free throw situation (resulting points multiplied with their probability):
2       *FT% +
POR     *(1-FT%)*OR% +
0       *(1-FT%)*(1-OR%)
=2*FT%+OR%*POR-FT%*OR%*POR

So, even this doesn't change.
The aspect of the game that it would really influence is the 'it is late in the game and we lead by three points' situation.
Because the opponent would not be able to make the first shot and intentionally miss the second shot - as there would be no second shot...

(Part of) How the world cup was won

Hello World,
I haven't written anything in a while (there is this thing called thesis looming...). But today for some reason I do not feel like working (I feel more like drinking Krombacher or something like that). After seeing everybody on the German team running his ass off yesterday (either that or getting punched in the face), I wanted to show a plot related to this. It shows all field players that played in at least 5 games (so you needed to at least reach the quarter finals). The x-axis is minutes per game and the  y-axis kilometer per 90 minutes (as always, click on the image to enlarge).
 
As you can see, there is a clear negative correlation between minutes per game and average speed. But if you focus on those players that played more than 80 minutes per game, you can see that all of Germany's offensive players and full-backs are running a lot. And Boateng and Hummels are also running quite much for centre-backs. (Note: In German full-back and centre-back is simply outside and inside defender - makes way more sense in my opinion...)
Now, I do not want to imply that this is the best way to play. After all, the Finals were super close and Argentina could have won as well. And if your strategy is to defend deep and then try to strike quickly, your offense doesn't need to run that much (so, if you want to bash Messi or brazilian one syllable strikers do it somewhere else please).
BUT, I wanted to show that a big part of the German game style is to run as much as possible as a team.
So, thanks to Schweinsteiger, Müller, Lahm and everybody else for playing great football the last 10 years (Klose since 2002!). I appreciate that you are running your asses off.

Cheers,
Hannes

Bridging the gap, Part III - Throwing the kitchen sink

Hi everyone,

for now, part III is going to be the final chapter of my Plus Minus / box score / tracking data comparison. Basically like 'Return of the Jedi', only with less Ewoks.

After looking at correlations between offensive and defensive Plus Minus and pairs of other data, I decided to look at general plus minus and everything at the same time. Using 17 different statistics, I am going to look at all possible combinations, to find the best ones for predicting the data. All possible combinations are in this case 2¹⁷-1 = 131071 = a shit load of possibilities. I also decided to add a new type of players to my previous groups of Point Guards, Wings & Bigs, which I called 'Very Bigs'. It's basically only those bigs that are not attempting any three pointer. The idea is to get a more homogeneous group.

Bridging the gap, Part II - Defense

Hi everybody,

last time I bored you to death, I tried to find those stats that correlate well with winning a game on offense.

Today, I will take a look at defense and check what in general correlates best with winning a game (because to win a game, you have to usually play both defense and offense).

As all the groundwork got laid out in my last post, I will directly start with the goodies.

DEFENSE

Plus Minus, Box Scores & SportsVU - a bit of bridging the gap (Part I)

Hello everybody!

I recently hit 1000 viewers which means - actually nothing (memo to myself: try to be first responder to as many Grantland posts as possible). Some weeks ago, after ESPN published Real Plus Minus (RPM), I dabbled a bit into comparing it to 'normal' box score stats - and I have to admit it was partly rubbish (but at least it looks cool!).

(Note: If you get bored during the next paragraphs, simply scroll down to the new fancy figures...)

The biggest critique points are in my opinion that RPM is a stat that already includes box score stats and that I used a model that only compared one stat with RPM at a time. The first problem is directly obvious: If I compare assists with a stat that indirectly concludes 'assists are super!', then I don't know nothing. The second problem is a little bit more tricky. Imagine that assists correlate with turnovers (which is actually true, so you do not have to try very hard). This influences the analysis, as turnovers are generally seen as negative and assists as positive (for some strange reasons), but both could correlate as positive.

So, I started to use multiple linear regression, which sounds more dangerous than it is. Linear regression is basically: you have beans lying on the floor. Put a stick on the floor so that the beans are on average as close to the stick as possible. In the case of two factors, your beans are floating in space and you have to put on your space suit and adjust a board in a way that the beans are as close to it as possible¹. I decided to not go further than two dimensions for the moment. That's probably another post.