Question on Individual Possessions

[EvanZ]

Evan, another idea, changed ORB% over the years. Over the years the ORB% became lower. Ed's formula has 26% in it, while it was 31% from 1981 to 2005 in average.

Still doesn't make sense to me. Rebounding percentages are for opportunities after *missed* shots, not made ones. The formula I gave should be correct. The one Neil gave is either mis-stating what Ed used or Ed was wrong or there is another reason that nobody has given yet.

[mystic]

Still doesn't make sense to me. Rebounding percentages are for opportunities after *missed* shots, not made ones. The formula I gave should be correct. The one Neil gave is either mis-stating what Ed used or Ed was wrong or there is another reason that nobody has given yet.

I agree that your suggested formula is more accurate. But again, how big is that difference for the time until 2005? I try to understand the equation, the lower ORB% might account for the difference, at least part of that.

[EvanZ]

Still doesn't make sense to me. Rebounding percentages are for opportunities after *missed* shots, not made ones. The formula I gave should be correct. The one Neil gave is either mis-stating what Ed used or Ed was wrong or there is another reason that nobody has given yet.

I agree that your suggested formula is more accurate. But again, how big is that difference for the time until 2005? I try to understand the equation, the lower ORB% might account for the difference, at least part of that.

Out of 100 FGA, roughly 50 are made. Out of 50 misses, roughly 75% are rebounded by the defense, thus ending the possession. That means 12.5 (I know, not a round number) did not result in end of possession, which would put the factor closer to 0.88*FGA possessions used by the player. My formula would have given (50+0.75*50) = 87.5, which is the correct number. Unless I'm missing something...

[mystic]

So, if we use the 31 ORB% of that timespan I mentioned, we end up with 0.84*FGA instead. No idea, I didn't check the thread, maybe somewhere is explained where the remaining 0.1*FGA comes from.

Edit: If we add the And1 thing, we can say roughly 0.83*FGA. It is still 0.09 off to 0.74.

[J.E.]

Out of 100 FGA, roughly 50 are made. Out of 50 misses, roughly 75% are rebounded by the defense, thus ending the possession. That means 12.5 (I know, not a round number) did not result in end of possession, which would put the factor closer to 0.88*FGA possessions used by the player. My formula would have given (50+0.75*50) = 87.5, which is the correct number. Unless I'm missing something...

OReb% off FGA is something like ~11%

[Mike G]

The Spurs and the Raptors are right next to one another in DReb%, .756 to .754
But the Spurs are best in the league at limiting opponent FTA (FT/FGA = .166), while the Raps are just about worst (.266)
So we may assume Tor is rebounding significantly more missed FT than is SA.

An estimate of DReb% of missed FG widens the gap to .745 vs .734
League avg FG-DReb% is estimated at .721, vs .736 of all rebounds.

[gfarkas]

By my estimate, there have been about 200 missed AND1 this season. There have been 18,326 made field goals. Is that not rare?

Edit: I should also add that of those 200 missed shots we should only expect around 10% of them to be rebounded by the offense, if I recall correctly studies that have been done on rebounding off missed FTA. So, that's about 20 made field goals out of 18,000 that did not end a possession for the offensive team.

It's still not clear to me where Ed's equation came from.

You're conflating 2 different things I wrote. The first is the occurrence of a made FG along with an And 1 FTA. The second is that same And 1 FTA being missed and then subsequently rebounded by the offense.

The second idea is, of course, a rare event, both relatively and absolutely.

However, the first is not that rare, in my opinion.

I just re-calculated totals for this season. There have been 17,389 FGA (my total was off before). There have been 641 made And1 attempts (assuming 75% FT%, that equates to roughly 200 missed And1 attempts).

If an AND1 shot is made, the possession is over, so I don't care about those. If it is missed, then we have 200/17,000 to worry about (~1%).

Do you want to keep going on about this?

Made or missed FTA is irrelevant... Either way, the FGM is no longer the possession-ending event, the FTA is.

[Mike G]

Whether an and1, or 2 FTA, or 3 FTA, the possession-ending event is either the last FT being made, or the defensive rebound of the miss.
It would be rather trivial to count subsequent FTA as separate events, except that they're recorded individually.