Don’t Try to Predict Upsets in Tournament Pools
Don’t try to predict upsets in tournament pools.
Posted March 14, 2011
Every year millions of people enter March Madness tournament pools, betting an estimated $2.5 billion. And every year most of these people think they can predict winners more reliably than whoever seeded the teams. Sure, there are some Cinderella teams that upset better opponents, but the best strategy for winning your pool is to stick to the numbers on the brackets. So why don't we?
Most of the information useful for predicting a win has already been incorporated into their seedings. So why do people think they can predict upsets? Two researchers, Sean McCrea of the University of Wyoming and Edward Hirt of Indiana University, decided to find out and reported their results in the Journal of Applied Social Psychology.
Maybe people think they have useful information not accounted for in seedings? McCrea and Hirt found that giving people team stats on top of seedings did not affect the number of upsets they predicted. Maybe people's judgments are biased by personal preferences? McCrea and Hirt found that people strayed from picking the better-seeded team just as frequently when they weren't familiar with any of the teams. Maybe people rely on the predictions of psychic octopi? McCrea and Hirt did not even deem this possibility worth mentioning.
More to the point, McCrea and Hirt found that people did not predict upsets as a result of thinking the worse-seeded team was actually the better team. So what's going on? The researchers concluded that fans adhere to a strategy called probability matching.
Let's say you're drawing balls from a large box that contains 25 red balls and 75 blue balls. Many people tasked with predicting draws will predict red 25 percent of the time and blue 75 percent of the time. They match their guesses to the probabilities of the outcomes, in this case yielding a 62.5 percent success rate on average. But if they just guessed blue on each draw, they'd be right 75 percent of the time.
Similarly, people know there will be a certain number of upsets in each NCAA tournament, and therefore betting on a Cinderella-free tourney seems silly. The only logical thing to do, they conclude, is to figure out when those upsets will take place. The drawback, of course, is that by shooting for perfection, they end up handicapping themselves. In McCrea and Hirt's research using real NCAA data, for example, people would have been much better off just sticking to the seedings.
The lesson is that in your office pool this year, you shouldn't try to be the hero. As long as no one else follows your steadfast strategy of not trying to outguess the experts, you've got a good shot of picking the Final Four alone and unscathed. Beyond that, it's all about whose mascot looks hungrier.