Tuesday, November 01, 2005

Nor are tempo-free stats some peculiarly exotic artifact available only from blogs. Something as familiar and mundane as a free throw percentage is, after all, a tempo-free stat. So are three-point FG percentages and assist-turnover ratios.

(Strictly speaking, of course, an overall FG percentage is also a tempo-free stat. It's just not a particularly useful one--and hasn't been since the introduction of the three-point shot. Read more here.)

But if you're interested in other things in addition to free throw and three-point percentages and A-T ratios, as most people reading this post no doubt are, then you need to ignore every other stat on the Big Ten (or any conference's) stat page. And I don't mean that to sound harsh. But I do mean it literally. "Scoring offense," "rebounding margin," turnovers, assists, individual points per game--they're all magnified or shrunk according to pace.

(Individual points per game does admittedly tell me one thing I find interesting. It tells me which player on his team the coach

And that's where hoops analyst

To count the number of possessions in a game we need to find those "events" in the box score that mark the end of a given possession. Turns out

1.

Thus the first element in the equation is: (FGA - oreb).

2.

3.

Through a highly advanced and oh-so-technical method known as, um, watching the games and counting. Immediately following the 2005 season, blogger extraordinaire

(This number, known as a free throw multiplier, will change according to the particular FT rules of the league or level you're looking at. Thus the NBA number is different than the college number.)

So, to recap, the sum of these three elements--FGAs absent an offensive rebound; turnovers; and about 47.5 percent of the FTAs--gives us our estimate for number of possessions:

FGAs - orebs + TOs + (0.475 x FTAs)

(Disclaimer: there are hoops realities that can be missed or at least not captured perfectly by this equation. For example, in the scenario used above where the FGA goes in and the shooter is fouled, the equation views the "and-one" free throw as something akin to half (0.475) a possession. We view it, of course, as a continuation of the previous possession. Which is why I recommend the following course of action....)

The easiest way to apply this equation, of course, is simply to take a team's season totals for FGAs, orebs, TOs and FTAs and plug and chug. I'm certainly not here to tut-tut and rap knuckles over the proper usage of a method I had no hand in creating. And goodness knows even the plug-and-chug method should yield results that shed some interesting light on the more standard tempo-skewed statistical fare. But for my own purposes, I prefer a slightly different approach....

Because running the numbers through this equation yields an

Take Michigan State's Sweet 16 win over Duke last March. Here are the relevant totals for the Spartans:

65 FGAs - 16 orebs + 16 TOs + (0.475 x 23 FTAs) = 75.9 possessions

Duke's numbers looked like this:

51 FGAs - 9 orebs + 22 TOs + (0.475 x 24 FTAs) = 75.4 possessions

Averaging these two results gives me the number that I use for the game: 75.7 possessions. If you do this for every game Michigan State played last year--that is, find the average between MSU's estimated number of possessions and their opponent's in each game--and total the averages from all 33 games, you arrive at the following number: State had about 2,285 possessions last year.

That number again: 2,285. (The plug-and-chug method, by the way, yields a result of 2,261.)

First, a quick note on what

What I think most people mean, though, when they say "average number of possessions per game" is something more like: "assuming a 40-minute game, how many possessions will there be?" So we need to adjust the 69.2 down slightly. When you hear me say "Michigan State averaged 68.5 possessions per game last year," then, keep in mind the ultra-accurate phrasing would actually be: "Michigan State averaged 68.5 possessions per 40 minutes last year." Bottom line: count OTs and adjust accordingly.

Now on to the good stuff....

With 2,285 in our back pocket, we can look at an array of familiar stats for Tom Izzo's team--but now on a

Michigan State recorded 1.13 points per possession last season (2,590/2,285), 0.247 assists per possession, and 0.197 turnovers per possession.

These are numbers based on the Spartans' entire 33-game season, including games against opponents like Nicholls State, Delaware State, and Oakland. No offense against any of the above, but I prefer to look at

For instance: Michigan State scored 1,183 points on 1,048 possessions in their 16 conference games, yielding a points-per-possession (PPP) figure of 1.13. You will often see this

Lastly, subtracting the defensive efficiency number from the offensive efficiency figure gives you a result often called the

Once again, we estimate the number of possessions with this handy little item:

Possessions = FGAs - orebs + TOs + (0.475 x FTAs)

The four factors on the right side of this equation give us

Here are the most commonly used tempo-free measures for each of these four factors on

1.

2.

3.

4.

The efficiency measures for

1.

2.

3.

4.

(Note that a team's offensive free throw efficiency is measured not only according to how often they get to the line but also according to how well they shoot once they get there. How well your

That, in a (rather large) nutshell, is an intro to tempo-free stats for teams.

Now that we have the basic principles covered (and rather than harangue you for another 2,000 words), I think a series of links should suffice on this front....

On the offensive side of the ball, I like the simplicity and intuitive cogency of

For a given player, we can also determine an estimate for their own

And, for his part, Dean Oliver has developed (much) more sophisticated measures of individual offensive performance--read more here. (Oliver is even working with the WNBA on a project to record individual tempo-free

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