The difference is, while 10 PAs are certainly not predictive, nobody would argue those 10 PAs (whether the dude hit 1.000 or .000) weren't accurately measured. Those 10 PAs did happen, and we know, for certain, what the results were. We can use those 10 accurately measured PAs, in conjunction with another 10 and another 10, and so on, to accurately measure what happened, and perhaps form an educated opinion about what is likely to happen in the future. Defensive metrics aren't sold that way. Everyone admits small sample sizes do not necessarily represent what actually happened. But those same people then turn around and claim "more inaccurate data" will solve the accuracy issue. I don't think it does. I think adding 10 accurately measured PAs to another 990 of the same gives you an accurate picture of what happened. But adding 10 inaccurately measured defensive plays to 990 other inaccurately measured defensive plays doesn't.