Straight-up picks can't distinguish good pundits from bad
Experts are no better at picking winners of NFL games than a simple algorithm, "Numbers Guy" Carl Bialik reports in his latest Wall Street Journal blog posting.
The easy method is dubbed the Isaacson-Tarbell postulate, after the two readers who proposed it. Pick the team with the better record; if the two teams have the same record, choose the home team. According to ESPN.com's Gregg Easterbrook, no pundit was able to beat Isaacson-Tarbell. Only one was able to tie.
"You don’t need incredible insider information, you don’t need to spend hours in fevered contemplation … Whatever you do, don't think!"
While normally I love to join the "Super Crunchers"-esque refrain that formulas often know better than "experts," I don't think it really applies in this case, where you have to pick winners straight-up.
NFL matchups are often lopsided. If an .800 team is playing a .300 team, it's obvious that you have to pick the .800 team. No matter how expert you are, no matter how much insider knowledge you have, you simply aren't going to be able to know that the .300 team is better, because it *isn't* better. The same is true for a .700/.400 matchup, or even a .650/.450 matchup. You may be more expert than the rest of the world, but the rest of the world isn't dumb. Everyone picks the .650 team over the .450 team, so your insider knowledge doesn't do you any good. The best you can do is to *tie* the rest of the dumb-but-not-that-dumb punditocracy.
It's only when it's a close matchup that expertise can come into play. Suppose that two evenly-matched teams are going at it, and most experts think team A has a 52% chance of winning. So, they pick team A. For you to outpredict those guys, you have to have insider knowledge, and that knowledge has to be in the direction that leads you to believe that team A has *less than a 50% chance*. That's the only way you'll predict team B will win, and the only way you'll be the rest of the (A-picking) experts.
How many close matchups are there in a season? Maybe one or two a week? Suppose there are 30 close games a season. In those, the best predictor might be more accurate than the pack, say, 50% of the time (to be generous). That's 15 games. In those 15 games, 7.5 will be more accurate go the "wrong" way -- that is, the additional expertise will confirm the pack's pick, not contradict it. That leaves 7.5 games left. Again to be generous, call it 8.
So, in eight games a season, the expert predicts a different team than the pack. But those eight games are already pretty close, almost 50/50. It's probably the case that the pack thinks they have a .520 pick, but they only have a .480 pick. So the expert has a .040 edge for eight games a year. Over 256 games, the best, most expert pundit has an advantage of about a third of a game.
Is it any wonder you can't find out who the experts are by picking straight-up?
If you want to evaluate the experts, just have them pick against the spread. Now *all* the games are close to 50/50, not just 30 of them. Now, the expert has a fighting chance to emerge from the pack.
Most of the touts I've heard of *do* pick against the spread. I haven't seen how they've performed, long-term, but I bet most of them are pretty close to 50%. And, if so, *then* you can conclude that those so-called insiders can't beat a simple algorithm.
But looking at straight-up picks? That's like trying to find the best mathematician in a crowd by asking them what 6 times 7 is. Under those circumstances, the Ph.D. will do about as well as a sixth-grader. It doesn't mean the guy with the doctorate in mathematics doesn’t know more than the eleven-year-old. It just means you asked the wrong question.