The Hardball Times: Accuracy no small matter in fantasy projections
For those following along with the debate over at the
Far too much has been written at CR for me to dig through and try to find the exact quotes, so forgive (and correct) me if this isn't perfectly accurate, but essentially, those on the "intuition" side of
This line of thinking seems to be becoming more and more prevalent in the fantasy industry, even among those with reputations as "stat" guys. One of the analysts at the forefront of this movement is
I disagree with this.
Shandler, more recently,
Maybe, but by that logic, a 21 HR projection wouldn't look so bad either, and I think we can all agree that a 21 HR projection for Miguel Cabrera would be way off-base.
Well, of course it's going to increase our accuracy. We're getting 10 guesses instead of one. "In the 30s" will never be wrong when "37" is right.
I think the problem here (and perhaps I'm misinterpreting) is that we seem to assume that this error bar is static, that Miguel Cabrera has one fixed error bar and that we're completely justified in projecting any number of home runs within that error bar, and that if we do this we'll be fine. But that's not true. Every number from 30 to 39 is going to have its own individual error bar. Because that "30 percent error bar" exists, if all we were to say is that "Miguel Cabrera will hit HRs in the 30s," we
Why? Because if we're not saying that he's going to hit 35 HRs, then that error bar looks very different:
Neither of these bars covers all the HRs in the 30s. So in actuality, by trying to remove precision, it seems that we may actually just be fooling ourselves. In trying to remove precision, we're actually implying precision (strange as it is), but not the good kind that's well thought-out. Rather, it's the rounding-off kind. So if we're going to be precise no matter what, why not make it count? Put me down for 37 home runs.
My point essentially boils down to this: if you're using a range of outcomes as your projection, you're using an error bar. And if you're using an error bar, you're necessarily implying a precise projection -- whatever happens to be in the middle of that bar.
In a similar vein, Shandler posited in a March newsletter that perhaps we shouldn't take consensus No. 1 pick
Yes, but how could we have known that Ichiro or Lee or Reyes would have been No. 1? Had we known, they would have been taken No. 1, wouldn't they have? Or at least they would have been in the top 15. Just because a non-top 15 player has a good chance of finishing No. 1 doesn't mean we know who it is. Sure, we could have guessed and taken Ichiro, but we could have just as easily guessed and taken
I'm not convinced that Shandler is looking at this the right way. Sure, odds are Albert Pujols
Albert Pujols: 12%
Twelve percent may not be that high (and I'm just making these numbers up, they may be way off), but it's the highest of anyone else on the list. Were the list of available options to look like this, it'd be a different story:
Albert Pujols: 12%
To put it another way, it makes no sense to take a guy like Jacoby Ellsbury just because Pujols has some chance of not being the No. 1 player. Let's do one more thought exercise using a graph of Pujols' and Ellsbury's expected value distributions based upon the "30 percent error bar" (assuming reasonable $40 Pujols and $33 Ellsbury projections).
Sure, a scenario exists -- and a somewhat likely scenario, at that -- where Ellsbury is more valuable than Pujols. But we can't take Ellsbury over Pujols just because in a few scenarios he could end up being more valuable. In far more scenarios, Pujols will be more valuable (and in one he's almost $20 more valuable!). And this will be the case for every single player who is an alternative to Pujols (assuming you have Pujols ranked No. 1 on your cheat sheet, of course).
If you like Jacoby Ellsbury better than Albert Pujols, sure, take him No. 1 if you can't trade the pick and he won't be there in the second round. But don't take Ellsbury just because Pujols' chances of finishing No. 1 are low in an absolute sense.
I know it seems like I'm picking on Shandler a lot here, but that's not my intention. I have the utmost respect for Shandler and what he has done for the fantasy industry. I used him for most of my examples precisely because he is such an influential figure, because he is at the forefront of this line of reasoning, and because he has been so vocal about it in recent years. I think Ron is a very intelligent and talented fantasy player; I just don't agree with him in this instance.