Vote: Greatest football coaches ever

Beginning May 23, ESPN.com will unveil its experts' choices for the 20 greatest coaches in the history of the NFL. Before that process begins, fans have the opportunity to vote for their own top 20 (CLICK HERE).

The ballot includes both active and retired coaches, and Patriots head coach Bill Belichick headlines the group of active coaches. With 187 wins, a .649 winning percentage, 18 postseason wins and three Super Bowl trophies to his name, Belichick is the most decorated of the 32 current head coaches. How his resume stacks up to those of such coaching legends as Vince Lombardi and Bill Walsh in the eyes of the voters will be uncovered later this month.

Former Patriots head coach Bill Parcells, who guided the team to an appearance in Super Bowl XXXI, is also on the ballot. Parcells recorded 172 wins as a head coach and won two Super Bowls with the Giants, while also enjoying success in multiple NFL front offices. He was instrumental in resurrecting both the Dolphins and Cowboys franchises late in his career.