Out of 36 governor's races on the ballot this year, around a dozen are too close to call heading into Election Day. Averages of the public polls show 11 sets of gubernatorial hopefuls within 4 percentage points and another six within 10 percentage points. By another measure, eight contests look like they could be won or lost by less than 2 points, a feat not seen in any election cycle since at least 1900.

That means this year could break or tie the previous record for losses by incumbent governors. Read more.