Not quite sure if you are understanding true shooting.

I think I do, and I'm challenging some of its assumptions

Do you understand why a free throw takes up 44% of a possession under he formula? It's because the guy who made up the stat did some research and found that 12% of all free throws are technical free throws and and-ones.

Under his definition and 1s also include the third FT on a fouled 3pt attempt. Basically he took total FTAs divided by lost possessions from FTs and found he had too many FTs so he put in the modifier.

So on average, two free throws are slightly less than a single possession. Obviously that assumption may not hold true under a single game. But over the course of a season, it probably holds fairly true.

I think this is a flawed assumption and where TS% as a stat breaks down.

Over the course of a season I think the rockets average about .44 possessions per FTA. But that doesn't hold true on an individual level. Harden picks up FTs through technical fouls on other rockets but never losses any because if he gets fouled he'd take the FTs anyway. That's never gonna even out.

The statistician realized that there are slightly more than two FTAs per possession and wanted to reward players who could unlock those extra opportunities for points through and 1s. The problem is he spread that reward uniformly across all FTAs. There shouldn't be any difference between a made layup and two made free throws after a foul on a layup attempt. Both have two points on one possession, equally effective. But because of the modifier two made FTs is considered the most efficient way to score points. More than a made basket and a made and 1 which is actually the most efficient way to score. I Was talking about possessions because you're missing the forest for the trees.

Ts% makes harden look like a scoring God when really he just takes a lot of free throws. A better metric would be and1%

I'm not sure why you think it's that flawed- it's only flaw is that because and-ones and technical free throws aren't distinguished from normal shooting fouls on the box score, it's not possible to get a 100% accurate scoring efficiency stat using the box score. But it's pretty accurate and as good as it gets using just the box score.

Very true but why are we limiting ourselves to box scores? How far back does play by play data go?