Pure point rating
Pure Point Rating is a stat meant to quantify passing/ballhandling ability better than the traditional Assist-to-Turnover Ratio. It was invented by ESPN's John Hollinger.
To quote Hollinger:
"Ever done something out of habit even though you know it doesn't make any sense?
You're not alone. NBA execs do it, too. For a good example, consider how they evaluate point guards.
Coaches and personnel people almost instinctively look to a player's assist/turnover ratio to check how he's doing. But ask them why they look at assist/turnover ratio, and you'll get lots of blank stares and convoluted answers. Probe further, asking if they think Reggie Miller would make a better point guard than Steve Nash, and you'll quickly get a series of guffaws. But guess who had the better assist/turnover ratio last year?
Yet, in spite of the logical disconnect of a name like Miller's showing up near the top of the list, some still insist on using assist/turnover ratio to gauge point guards. They're getting some confusing information. For instance, this year's leader, for a second straight season, isn't Nash. It isn't Jason Kidd or Baron Davis or Brevin Knight, either. It's (drumroll, please) … Antonio Daniels. Does that mean Daniels is really better than those guys at running a team? Of course not.
What it really means is almost nothing, because assist/turnover ratio is a flawed stat. The problem isn't with "assist" or "turnover," it's with the "ratio."
Using a ratio is faulty for two reasons. First, it assumes assists and turnovers are equal, when in fact a turnover is more costly than an assist is helpful.
Second, it equates very different amounts of productivity. If Player A just sits in the corner all season and finishes with three assists and one turnover, while Player B directs the offense all year and has 300 assists and 101 turnovers, then according to assist/turnover ratio, we should assume that Player A is "better" at running the offense.
Fortunately, there's an easy way to fix assist/turnover ratio. It's a stat I call Pure Point Rating, and it mends the two flaws I mentioned.
First, it adjusts for the fact that assists do less good than turnovers do harm by multiplying assists by two-thirds. There's a factual basis in this. As I noted in a recent column, of the three acts of creating the basket (getting open, making the pass and making the shot), the passer does one. So we give him one-third of the credit of a 2-point basket, or about two-thirds of a point. Since turnovers cost almost exactly one point (teams average about 1.02 points per possession), we needn't make any adjustments to that part of the equation.
The second adjustment is measuring productivity, to avoid the Player A vs. Player B situation above. The way to do this is to sum a player's accomplishments on a per-minute basis, then adjust them for his team's pace. Finally, multiply the end result by 100 to make the numbers more user-friendly. The final equation is:
Pure Point Rating = 100 x (League Pace / Team Pace) x ([(Assists x 2/3) - Turnovers] / Minutes)
Using Pure Point Rating instead of assist/turnover ratio yields vastly more believable results. The Reggie Millers and Antonio Danielses disappear, replaced by some names we're used to seeing in discussions of the game's best "pure" point guards."
