APBRmetrics

Doesn't this really undervalue players who rack up huge quantities of AND1's? And conversely overvalue players who don't?

Doesn't impact it much, actually. Using PBP, you can get a more precise true shooting % rather than this formula, but for most purposes, TS (as it is) is fine.

The .44 is just an estimate of how many free throw attempts end a possession; not all do because they could be the first of a pair, for example. It doesn't say anything about how much a free throw is 'worth'. As far as that goes, a player who gets to the line enough could actually appear more efficient than someone who gets his points shooting from the floor since free throws use relatively fewer possessions. For example, player A could score 25 on 10 shots from the floor and 10 free throws (say, 6-8 on twos, 2-2 on threes, and 7-10 at the line) for a true shooting percentage of 25/[2*(10+.44*10)] = .868 while player B scores 25 on 15 shots (say 8-12 on twos and 3-3 on threes) for a true shooting percentage of 25/[2*(15)] = .833. Both players had the same accuracy on twos and threes, but player A was more efficient because he used fewer possessions to get there. I just made up the numbers so there isn't a big difference, but hopefully it gets the point across.

Doesn't this really undervalue players who rack up huge quantities of AND1's? And conversely overvalue players who don't?

Yes, it underestimates the TS% of scoring with lots of and-1's. You may assign a value to a higher TS%.
You may also assign a value to the player for drawing fouls on the opponent.
Of course, you may consider turnovers, assists, and numerous other things in a player's offensive efficiency.

TS% just estimates a player's actual scoring % when he gets the shot off.
As mentioned, you'd have to use PBP to get his "true" TS%. In fact, it's been done, and the differences are small.
I'd guess 90% of players have "true" TS% within .005 of their estimated TS% .

Yes I was wondering about how much in error the results would be with using the coefficient of 0.44. I was actually thinking about the 0.44 factor in regards to calculating possessions used, not true shooting percentage. I suppose players who also rack up a lot of technical free throws would also be undervalued, though this effect is probably also very small. Basically I was overall just wondering about the overall validity of using the 0.44 coefficient when calculating possessions used.

Do you know of any place where I could obtain And 1 attempts as well as technical free throw attempts? And defensive rebound percentage on free throws that are available to be rebounded? Or what about the fraction of field goal attempts that are associated with no rebounding opportunity (air ball out of bounds)?

Thanks.

Hoopdata's player pages have per-game And1 averages.

http://www.hoopdata.com/player.aspx?name=Kobe%20Bryant

For example, Bryant managed .76 And1s per game last season.

Yeah I knew Hoopdata had And 1 makes, but not And 1 attempts. I know the attempts could be estimated using free throw percentage, but I was just wondering if there were any sources out there that specifically tracked And 1 attempts.

Wait are And 1's defined as field goal makes with the foul? Or are And 1's only credited when the free throw is converted?

The .44 is just an estimate of how many free throw attempts end a possession; not all do because they could be the first of a pair, for example. It doesn't say anything about how much a free throw is 'worth'. As far as that goes, a player who gets to the line enough could actually appear more efficient than someone who gets his points shooting from the floor since free throws use relatively fewer possessions.