You can gauge the race for the Senate daily here using The New York Times statistical-election forecasting machine called LEO. The current odds give Republicans a 55 percent chance of retaking the Senate. What does that mean? Not much.
Republicans’ chances of gaining control of the Senate have improved slightly in the time Leo has been up and running. When we launched Leo two weeks ago, Republicans had a 49 percent chance of gaining control, according to the model. Now, we give them a 55 percent chance. So why the change? Part of the reason is some positive polling they’ve had in Colorado and Alaska, but 49 percent and 55 percent really aren’t very different.
Let’s say you have two biased coins, one that comes up heads 49 percent of the time and another that comes up heads 55 percent of the time. You want to figure out which one is the 55 percent coin. If you flip both coins repeatedly and choose whichever coin comes up heads more often, how many coin flips would it take to be confident that you’d made the right choice?
The answer: 375. It would take 375 flips to be correct 95 percent of the time. If it took you five seconds to flip both coins (and record your answers, all the while keeping track of which coin is which), it would take a you half an hour of doing nothing but flipping coins to be able to confidently differentiate one coin from the other.
The race for Senate control really is still a tossup.