Beating the Basketball PhDs

My draft model is currently a work in progress, but, as of the second pass it has beaten the actual GM's doing the drafting in the training period (2002-2011 drafts).  It does so even using the best fit line for the draft order, a logarithmic curve, that gives the maximum value to early round selections. It is important also to say that the draft model is built purely on public information that was available at the time of the draft, namely how old the players were and how they performed at the game of basketball.

Granted, my model measures success as the player's performance as measured by Alternative Win Score (AWS), and it's safe to say none of the B-Ball Professor's running teams in the oughts were looking to maximize AWS,  as Baxter Holmes noted in a recent SportVu article only a few front offices at the time had anyone doing analytics.  But, Layne Vashro has built a model that beats the front offices at selecting talent based on Wins Shares and RAPM.  And Arturo Galleti has built a couple that beat them as measured by Wins Produced, and so on.  The only thing I haven't seen is one built off of Yay Points! that beats the traditional GM's.

In fact it is almost distressingly easy to beat the Basketball PhDs at picking draft picks.  But, as always, there are caveats.

The Rarity of Jeremy Lin

The one thing that retro models have as an advantage of knowing who was drafted, and out of necessity when we build our retrospective models they are based on the players that were selected.  The drafters, of course, did not know this and have to do a filtering process that starts with a great many more potential picks than 60.  

It may be that there are many gems the scouts and front offices pass on that analytics would have revealed, but the truth is that players who go undrafted and catch on with a team after Summer League or a brief stint over seas and have a major impact in the NBA are very rare.  That surprise was a big part of the whole Lin-snaity phenomena.  

For that reason I keep my model to the Top 100 prospects and am somewhat leery of any claims that some completely obscure player with great numbers will be a star player.  The scouts and executives are clearly adding value, even to models that claim to beat them.

This is also seen in that when I include draft order in my model the results on the training set improve, and the coefficients adjust somewhat, as Vashro explained in a great write up of his model a couple of weeks ago. In my current working model when draft position is included age is greatly reduced as a factor, though still significant, and Usage, a measure of how many possessions the player finishes, becomes more negative than it is in the model not including draft position.  That indicates, basically, that the PhDs may have been over valuing volume scoring, which not a surprise.

The proper way for a front office to evaluate players is to combine the analytic approach and the information from the scouts.   In fact, there is no inherent reason a good portion of the private scouting data can't be evaluated analytically.  As qualitative and categorical data is often analyzed in social sciences and business.

 Modeling Frank Kaminsky

That gets to Wisconsin Center Frank Kaminsky, who has sat a top many statistical analyses, but has yet to make a mock draft board or the Draft Express Top 100 that I use as a proxy filter for my analysis.  After his continued strong tournament and efficient 28 point Elite Eight game, that may be about to change.

Kaminsky has definitely put himself in the conversation with the season he's had. Barely played his first 2 years, now a legit NBA prospect.

— Jonathan Givony (@DraftExpress) March 30, 2014

 Jonathan Givony also brought up a separate and intersting point on Kaminsky that may explain part of the reluctance of Draft Boards to add him to their list.  It is very rare for a player in college to receive as few minutes early in their career to go on to be drafted.  But, while playing time is an indicator of ability to play it is not absolute.  Maybe Kaminsky was a later bloomer, or maybe Bo Ryan was a little slow to trust him on the floor.  In any case if the scouts think he's worthy of inclusion, my model will slot him in.

 

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