Can someone explain indivdual ORTG, and DRTG?

[Hendrix]

How exactly is this calculated?

It doesn't seem to be the same as points scored/100 possesions when a players on the floor. Doesn't seem to necessarily be linked to TS%. I've looked around, and never seem to be able to find where the # comes from.

[mysticbb]

You will find the formula for those ratings in Dean Oliver's book "Basketball On Paper". Offensive rating starts at page 149 and defensive rating at 198. If I find the time, I can type a few things about that tomorrow. (well, if nobody else will do it before)

[Treilanin]

Check out http://en.wikipedia.org/wiki/APBRmetrics, it gives the formula used to calculate ORTG and DRTG though depending on the system some of the constants can change.

[erudite23]

Dude was asking for INDIVIDUAL ORTG and DRTG. Something that I've long been interested in understanding, but haven't found an explanation for yet (on the net).

[TheSecretWeapon]

Individual offensive rating is points produced per 100 individual possessions used. The stat was developed by Dean Oliver, as mentioned above. The stat incorporates points scored, assists, offensive rebounds, shooting efficiency and turnovers. It's the most comprehensive measure of individual efficiency available. It isn't perfect because it uses value estimates based on team context for assists and offensive rebounds. Someone over at APBRmetrics extracted data from play-by-plays, which changed the ratings a bit for some players. Overall, offensive rating for individuals is very useful.

Individual defensive rating isn't quite as good. It uses existing defensive stats -- defensive rebounds, blocks, steals, fouls -- to estimate defensive usage (how many possessions each player was responsible for defending) and "stops" (how many times that defender prevented the other team from scoring). Defensive rating is still okay, so long as you bear in mind that those estimates are just that -- estimates. Those estimates are usually okay for guys who get defensive boards, block shots and/or steal the ball frequently. For defenders like Dumars or Battier or Bowen, those estimates aren't going to capture their contributions.

Defensive ratings can be improved quite a bit by replacing the estimates with hand-tracked data. The tracking can be pretty time-consuming, however. And it takes some knowledge and basketball experience. The data is worth it (speaking from personal experience tracking games), but the NBA and teams haven't shown much interest in paying for it. (They're happy to use it when it's free, however.)