So just how much is a poll lead for the Iowa caucuses really worth at this point? That's the big question after the latest CNN/Des Moines Register/Mediacom poll was released this weekend.

For those that weren't deeply in the polling weeds, former Vice President Joe Biden led the field at 24%. Vermont Sen. Bernie Sanders, Massachusetts Sen. Elizabeth Warren and South Bend, Indiana Mayor Pete Buttigieg followed with 16%, 15% and 14% respectively. Rounding out the top five was California Sen. Kamala Harris at 7%; no other candidate polled above 2%.

A look at polls taken at about this point in primary cycles since 1980 suggests that while Biden leads now, there's a pretty good chance he won't actually win the caucuses.

Assigning an exact chance to how polling this early translates to the eventual results is difficult because of the high number of candidates running and the traditional volatility of Iowa caucuses' polling. Only three eventual winners were polling at this point between 10% and 30% -- which is where the top four 2020 contenders in Iowa currently sit. Most have been above 30% (seven out of 14) or below 10% (four out of 14).