Using the exact percentages (as opposed to the rounded ones displayed by Manifold), I will calculate the total time during which the market is above 50% and the total time it is below 50% and resolve to whichever side had the market in their favor the longest. Times when the market is at exactly 50% will not count towards either side.

This is another variant of average-based markets, except that I am not using a real average this time. It is in some ways the opposite of this one (/JosephNoonan/will-the-average-log-odds-of-this-m), since it gives no extra benefit to a team that brings the probability to extreme values, while that one is designed to benefit a team extra for bringing the market to extreme values.