What do you do with "half-possessions" in play-by-play data?

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AcrossTheCourt
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What do you do with "half-possessions" in play-by-play data?

Post by AcrossTheCourt »

Half-possession: a possession at the end of a quarter or OT where the possession isn't completed because the clock goes off. Sometimes these possessions are only one second long and consist of a half-court heave.

In possession analysis, do you ignore these possessions? Do you include them like normal possessions? Weigh these by 0.5? It doesn't make sense to say a lineup "defended well" and gave up 0 points in this situation when they can last just a couple seconds.
J.E.
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Re: What do you do with "half-possessions" in play-by-play d

Post by J.E. »

Good question. I used to throw them away if the offensive team only had less than X seconds to get a shot off. I don't really know what a good X is, though. You might have to choose it somewhat arbitrarily.
Mike G
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Re: What do you do with "half-possessions" in play-by-play d

Post by Mike G »

Can you gather all the fractional possessions and calculate ORtg for 21 seconds in the quarter, 10 seconds, etc?

It may be that 20 sec. is worth more than 20/24 of a full possession, if average ORtg is more than that fraction; or that 4 sec. is worth less than 4/24 of a normal one. Or they may be close enough that you can just call it by the fraction that it is.

If you have ORtg of 55 in 12-sec. possessions and ORtg of 110 in full 24 seconds, what's the diff?
AcrossTheCourt
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Re: What do you do with "half-possessions" in play-by-play d

Post by AcrossTheCourt »

Yeah breaking it down by ORtg based on time left would be useful. I'll probably do that at some point.

Would weighing these possessions by seconds left/24 make sense? So if you had only 6 seconds left this possession would be weighed by 1/4 of a normal one.
Bobbofitos
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Re: What do you do with "half-possessions" in play-by-play d

Post by Bobbofitos »

AcrossTheCourt wrote:Yeah breaking it down by ORtg based on time left would be useful. I'll probably do that at some point.

Would weighing these possessions by seconds left/24 make sense? So if you had only 6 seconds left this possession would be weighed by 1/4 of a normal one.
would make sense if this is the expected pts (1/4th of league average) historically.

it's not linear though
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