&#8230- Psstt&#8230- TradeSports traders&#8230- Wanna be rich?&#8230- Do like David Pennock: Get a PhD&#8230- with a major in probabilities&#8230-

Although TradeSports’s individual state predictions and overall Senate prediction were entirely consistent, one might argue that traders underestimated the degree of dependence (correlation) among states’ elections. In fact, I made a few bucks selling the “GOP Senate control” contract on TradeSports using exactly that reasoning. The truth is, I probably just got lucky, and it’s nearly impossible to say whether TradeSports underestimated or overestimated much of anything based on a single election. Such is part of the difficulty of evaluating probabilistic forecasts.