Friday, February 27, 2015

Let them handle their business – a case against over-helping

Note: I was first thinking about making it a longer post, but then re-read this post by Nick Restifo and realized that he made already most of my points (btw: @itsastat is a great Twitter handle). So I'll keep it in short form.
Note2: After I finished writing, I realized that it became a longer post :D

Hi everybody,
for the last week, I was playing around with data scraping and visualization. In my opinion, the use of clustering and heatmaps is a great but underused way to get a first impression and overview of data. Especially, as there are no numbers needed to understand the results (yes, I'm looking at you Chuckster!).

Anyhow, I was looking at the NBA.com playtype data to see if there is any rhyme or reason in what makes teams good. The Synergy playtypes are very interesting in those regard that the word playtype is used very loosely. The following is in my opinion very important: Those playtypes that they use can be separated into three and a half main subcategories:

1: Active Playtypes: Isolation, PnR Ball Handler, Post Up, (Misc)
One player receives the ball in a more or less neutral position and tries to get into an advantageous position. It is really hard to prevent the initiation of these plays.
1.5: Semi-active playtypes: Hand-Off, Off-Screen
The defense can sometimes prevent the initiation of the plays (which can be more costly than allowing the play itself). Note that they produce on average slightly more points per possession than active playtypes, but they also happen less often (combined 10% of plays). This my be due to the fact that they are more complex (more actions/players involved)
2: Passive playtypes: Spot-Up, PnR Roll man, cuts, putbacks
These are plays that can be avoided. Note that 'can be avoided' does not necessarily mean that the defense is at fault if they happen. Take this cut by DeAndre Jordan (I guess it's a cut) one of the league leaders in cuts. You can either let Blake dunk directly or hope that he somehow botches the pass to DeAndre
3: Transition. You could argue that transition is more a result of offense than of defense. But that's a different story

Thursday, February 19, 2015

Data dump:Isolation is a meritocracy, miscellaneous is something you should avoid

Hi everybody,

this is mostly a data dump after I looked at the new nba.com Synergy Sports data (next stop tracking data!). Feel free to use the plots.
For players I always show those that have enough attempts

One personal note: The Synergy data can be easily wrongly interpreted. For example, a cut is mostly not a play itself. If you look at the players that attempt a lot of cuts, you find mainly center that most probably are beneficiaries from other stuff that is going on (cue to Blake Griffin throwing a lob to DeAndre Jordan).
Even though cuts have a high value for Points per possession, cutting all the time is not the solution. (This is a very personal note, as my last rec league team had a disastrous knack of cutting into whatever real playtype was going on at that moment...)

Cheers,
Hannes