Tuesday, December 23, 2014

Special guest post: TERP ALERT!!!!

Like the Championship team of 2002, this year's Maryland Basketball team is big and deep.  The interesting thing is that it has the potential to be as talented.  Think about it, big, deep and possibly talented like our championship team. Wow.

Let's take a quick look at a specific player who will help make that possible. We have Melo Trimble, the pg county freshman who is playing like one of the best point guards in the country who can be an NBA guy. But I'm not talking about him. Or Dez Wells, the Naismith 50 finalist who might be an NBA guy. Or Jake Layman, the 6'9 crazy athlete with a nice jump shot who was co-Big Ten player of the week who can be an NBA guy. Or our 7 foot freshman,Michal Cekovsky, who is better now than Alex Len was at the same time in his career (Len was an NBA lottery pick).

Orrrrrr . . . Richaud Pack, the seasoned transfer playing his last year of eligibility and  silently guiding this team with defense and calming smarts. Or Dion Wiley, another Prince George's County freshman guard who can shoot, has size, and is confident. Or Evan Smotrycz, a 6'9 shooter....or Damonte Dodd, our starting 6'11 center who defends the rim...or 6'9 hustle guy Jonathan Graham.

I'M TALKING ABOUT JARED NICKENS.  The 6'7 freshman who's been starting at the three while Dez Wells has been hurt. I'm not saying he's better than Dez overall, but he handles the ball better and has a better stroke than him right now (note his Juan Dixony release). Here's a video from a weekend tournament last year against solid high school opposition over 3 games:



If you don't love him throwing the subtle jab at the west coast while talking about how it's "fun" to play against the best competition, then you don't love hoopin'.
While Dez is physically gifted, he gives occasional glimpses of season's past with a spazz out here and a wtf was that there.  Nickens is a glimpse of the future, filled with mega cool and specific to basketball talent.   

That's not to say that we shouldn't look forward to Dez returning.  He's a beast and we need him.   But the more I see Nickens either making 3's or almost making 3's coupled with his lack of turnovers and enjoying defense, I'm starting to wonder how bad of a thing to the program Dez's injury is.
And he was supposed to be our best player.

Whoa - Maryland is back in a big way.  

Go terps.

Special guest post by the luminary John Beckham

Monday, December 8, 2014

Relationship between advanced stats and winning

While a growth in advanced metrics provides a more robust picture of a player's value, the true measure of a metric should be it's ability to correlate with his team winning. I took six advanced metrics from basketball-reference.com for the 2014-15 season* and focused on only players that had played a minimum of 100 minutes this season through the December 5 games (this resulted in a population of 342 players). 

I compared each player's team's winning percentage (win %) with i) usage %, ii) player efficiency rating (PER), iii) true shooting % (TS%), iv) box plus-minus, v) value over replacement player (VORP) and vi) win shares per 48 minutes (WS/ 48). The definition for each are pulled mostly from basketball-reference.com's glossary. Below each definition the specific matrix is plotted on the vertical/ y axis and win % is plotted on the horizontal/ x axis. 

Each blue dot represents one of the 342 players that qualified. I included a yellow linear regression line to exhibit the direction of the relationship. If there is a very strong relationship between the metric and win % then the yellow line will begin at the bottom left of the chart and rise steeply to the top right of the chart, which would indicate that as the metric increases so too does win percentage. I include an R-square to indicate how well the model fits the data (or how well the metric explains win %). The lower the R-square means that the metric does a poorer job explaining win %.

Usage %Usage Percentage (available since the 1977-78 season in the NBA); the formula is 100 * ((FGA + 0.44 * FTA + TOV) * (Tm MP / 5)) / (MP * (Tm FGA + 0.44 * Tm FTA + Tm TOV)). Usage percentage is an estimate of the percentage of team plays used by a player while he was on the floor.



PER: A per minute rating that adds accomplishments and subtracts failures (see formula here).



TS%True Shooting Percentage; the formula is PTS / (2 * TSA). True shooting percentage is a measure of shooting efficiency that takes into account field goals, 3-point field goals, and free throws.



Box plus-minus: A box score estimate of the points per 100 possessions a player contributed above a league average player, translated to an average team.



VORP: A box score estimate of the points per 100 team possessions a player contributed above a replacement-level player, translated to an average team.



WS/ 48: An estimate of the number of wins contributed by a player per 48 minutes (league average is approximately .1000).


The above shows that while all six of these advanced metrics has a positive correlation with team win%, usage, PER and TS% are weakly related (they have relatively flat lines). Box plus-minus, VORP and WS/ 48 have a stronger positive relationship but the r squares indicate that they only explain ~15-18% of the relationship between the specific metric and team win %. However the includes a player's team's wins are included as a component in the formula for ws/ 48, thus the stronger positive correlation and larger R-square with ws/ 48 are expected. As a result, box plus-minus and VORP, which includes box plus-minus in its formula, should be considered the best metrics in terms of correlating with team win % that don't also include a team's wins in the formula (based on this small sample).

*A major limitation of this approach is that it focuses only on one incomplete season (2014/15). I will try to run a similar analysis on these metrics over several completed seasons, which should give a more accurate picture of the correlation with winning.