Early Returns: True Usage and True Turnover Percentage

Nov 12, 2014; Washington, DC, USA; Washington Wizards guard John Wall (2) dribbles as Detroit Pistons guard Kentavious Caldwell-Pope (5) defends during the first half at Verizon Center. Mandatory Credit: Brad Mills-USA TODAY Sports

Last season, I started looking at a “cooperative” model of offensive usage. With the introduction of SportVU data such as the “potential assist”, it is now possible to examine players who influence offensive possessions, not just those who “use up” plays by shooting. With this new way of envisioning NBA offense comes a range over other new insights, including a better measure of turnover rates. Traditional turnover rate simply compares turnovers to shots, which has always had the perverse impact of making playmakers (almost by definition the guys best with the ball in their hands) appear to be turnover prone. By comparing turnovers to overall offensive involvement, we get a better understanding of who is actually turning the ball over relative to actually making things happen for an offense.

In any event, here are the first pass at 2014/15 True Usage numbers and related numbers. A quick refresher on the metrics.[1. Note that all possessions are based on NBA.com’s pace metric rather than TNC’s own as we don’t have possession totals for infividual players, yet] :

True Usage: Percentage of possessions in which the player is “involved” in the offense either by shooting (including drawing a shooting foul), potentially assisting (including FT assists, but not “hockey assists”) or turning the ball over.

Shot Usage: “Traditional” usage rate – shots + turnovers / possessions.

Assist Usage: Potential Assists (incl. FT Assists) / possessions,

True TO%: Turnovers as compared to possessions used either shooting or passing. League average is around 9.7%, slightly lower for PGs, slightly higher for bigs.

TOP%: Time of possession relative to the players entire time on the court not just when his team is on offense. Average time of possession is just over 7% as according to SportVU, the ball is only “possessed” for about 37 minutes of a 48 minute game.

Shot/Touch%: Percentage of front court touches ending with the player shooting.Varies widely by position and role (and does not take into account offensive rebounding, which explains the high numbers for many big men, though not Kobe’s chuckerific early season.)