Monday, November 11, 2013

4 Factors - Explanation

Okay, truth time ... I am aware that points per game, rebounds per game, field goal percentages, etc are very out dated stats, They tell you very little about your team or opponent. I am simply a lazy guy. It's very easy to pick up a box score and copy down the information.

There. I said it.

Now it's time to fix it. It's time to start listing something known as the "4 factors". The four factors are something that Ken Pomeroy has been promoting based on Dean Oliver's four factors concept. In a nutshell, these four stats give you a much better idea of how good or bad your team is when compared to every other team equally. I'll try to give you an insight into each. But before I start let's talk about offensive efficiency and points per possession.

Points Per Possession
Simply listing points scored per game by each team is an awful stat. Look at it this way. VMI is a super fast tempo team that isn't known to be a good shooting team. Wisconsin is a slow tempo team that usually shoots a better percentage. If I simply list WMI as scoring 83.2 (made up) ppg versus Wisconsin scoring 56.5 (also made up) points per game and compare them, you could say VMI is the better offensive team. But is that true?

Points per possession balances out the tempo a team plays in order to be able to compare them better. It divides the points scored by the number of possessions in a game (FG attempts - offensive rebounds + turnovers + .475 * FT attempts). Thus you are able to compare the offensive ability of Wisconsin and VMI and equal footing even though each team runs a different tempo.

By the way, think of the average as about 1.01-1.02 points per possession. Anything above that is pretty good. if your defense give up that or better, it's not so good.

Now let's move on to the real stuff ...

Four Factors

Efficiency FG Percentage (eFG %)
FG made + 0.5 * 3 pointers made / FG attempts

With some teams taking as many as a 1/3rd of their shots behind the arc, this stat is basically shooting percentage stat for the modern day game of basketball. It gives extra credit for made 3 point shots. Think of 47%-49% as about the national average.

Turnover Rate (TO%)
Turnovers / Possessions

This one is pretty simply to see an explain. 20 turnovers hurt a team that averages 65 possessions a game a lot more than one that averages 85 possessions a game. National average here is about 22%.

Offensive Rebounding Percentage (OR %)
Offensive rebounds / (offensive rebounds + opponent defensive rebounds)

"How well do you do at rebounding your misses" is the name of this stat. Saying you had 10 offensive rebounds means nothing when you only rebound 10% of your team's missed shots. National average is about 30%.

Free Throw Rate
FT attempted / FG attempted

The aggressive stat. How often do you get to the free throw line? Are you content to just take jump shots and not attack the basket? National average is around 35.

I will try to post these 4 factors sometime in the post-game reports. I'm still lazy and will continue to use the other stuff I normally use as well. I'll just throw these in too. Special thanks to this post at Midwest Sports Fan for making things even clearer for me.