Tracking one’s players’ points and rebounds is easily one of the most casual ways of entering the analytics fray as a beginner. Even for the metrics disciples among the coaching ranks, it’s worthwhile to examine this view, if one hasn’t already done so.
I would guess that most coaches have casually looked at their player season cumulative stat sheet and observed from time to time that certain players have relatively big numbers in certain stats for the relatively small number of minutes that they play.
To illustrate, let’s take an exaggerated example: Player A (who very well might be a 3pt specialist) averages 8 PPG. in 12 minutes of playing time. To get his average points per minute, we simply divide his points by his minutes (8/12= .67 points per minute or PPM). To get Player A’s adjusted value, we simply multiply .67 by 32 minutes (21.44 PPG), 40 minutes (26.8 PPG), or 48 minutes (32.16 PPG) depending on whether the player is a High School, College or Pro performer.
For argument’s sake, let’s also say that Player A averages 2.7 RPG in his 12 minutes of PT. Obviously the formula is the same for rebounds. In this case, we divide average rebounds by average minutes (2.7/12= 2.22 RPM. Again, to get Player A’s adjusted rebound value, we simply multiply 2.22 by 32, 40 or 48 minutes to arrive at adjusted game averages of 7.0 for high schoolers, 8.8 for collegiate players and 10.56 for pros.
Let’s assume Player A is a high school player, so his adjusted game averages of 21.44 PPG and 7.0 RPG are eye-opening for only 12 minutes of playing time. One would argue, for any number of reasons, that Player A wouldn’t be able to sustain those averages for 32 minutes. The argument goes like this, “the reason he has those averages is BECAUSE he plays limited minutes.” Certainly, many times the theory of diminishing returns will be in effect. No matter, the only way to prove that Player A can’t sustain very good play with bigger minutes is to PLAY him bigger minutes. Then the stats will bear the truth and eliminate the need for assumption.
One might also argue that Player A is a defensive liability and that’s why he only plays 12 minutes a game. I would argue that unless one can prove statistically that Player A gives up more than 8 points while he’s on the floor, he is still a plus while he’s out there. After all, one of the oldest ways to gauge a player’s performance is, “Did he outscore his counterpart?” In essence, that’s really what we expect of a player, in the end. Is he a plus out there on the floor, or a minus? Simply put, one wants all 5 players to outscore their counterparts, but in reality, we’ll take any plus from any player we can get for the W.
But, we digress a bit. We merely look at points and rebounds per minute as a tool to help us evaluate the minutes we give our players. If the playing time we give our players is founded foremost in trying to win games, we are constantly asking ourselves, “Who Plays, Why Do They Play, When Do They Play, For Whom Do They Play and How Long Do They Play? Part art and part science, juggling personnel and playing time is among the coaching skills that is often underestimated. Effective management of personnel, in general, is easily the most overlooked aspect in coaching. Otherwise, how does one account for how few times one hears this topic addressed at clinics and the like? It’s almost amusing that coaches universally seem to believe that they don’t need improvement in this area and yet are consumed by X’s and O’s quests.
We’re not advocating rewarding all players with gaudy stats in limited playing time. Rather, we’re advocating CONSIDERING points and rebounds per minute as another tool in the ongoing player evaluation process.
One might ask, why not also consider assists per minute? Assists are actually taken care of quite nicely by the assist to turnover ratio that most teams use. For example, 60 assists and 30 turnovers computes to the same ratio of 2 to 1 as 6 assists and 3 turnovers. Playing time is implicit in this ratio.
Lastly, one might ask why not also consider blocks and steals per minute. In previous articles, we’ve steadfastly pointed out that blocks and steals can actually be negative stats for a player, if his attempted blocks and steals consistently place his team in jeopardy and give up points.
For instance, 2 steals looks good on paper. Let’s also say 2 points are scored on those two steals. But, subsequent video work shows that same player missed 3 steals which resulted in 3 points by the opponent. A seeming +2 on the two steals turns into a -1 after analysis. The same theory applies to blocks. All stats can be “un-pure”, but steals and blocks are the most suspicious.
Like any other metric, points per minute and rebounds per minute can sometimes point coaches in personnel decision making that they might not otherwise navigate.
Very good playing time article. I like how you show how to calculate a player’s adjusted value. Making that calculation gives everyone another level of stats to help evaluate players.
I have developed an iPhone app that you might be interested in. It helps base the Playing Time Discussion on facts.
The app is called AllyOOP and it lets the Parents track the good and bad plays made by their kids during the game. It then gives them an overall score and also shows them the areas that they are excelling in and where they need improvement.
Check out a review of AllyOOP at http://bballmag.net/playing-time-part-2/