All of America’s professional sports teams are loaded with talent. The drafts for the NHL, MLB, NBA, and NFL are designed to make sure that even the worst teams have a better chance at getting impactful players. Yet certain franchises are able to rack up championships, while others miss the postseason year after year — because coaching makes all the difference.

24/7 Wall St. used data from the Sports Reference family of sites on coaches from the NFL, NBA, MLB, and NHL. We considered their regular season records, playoff success, and championships won to determine the greatest coaches of all time. Coaches who were not in charge for the equivalent of at least one full season were not considered. Baseball managers whose careers ended prior to 1903, the start of the World Series era, also were not considered. Competitor leagues like the ABA and AAFC also were not considered.

Arguably, the most important job of a coach is to get the best out of his players. But even the greatest coaches of all time would struggle to win with substandard athletes. Similarly, the greatest players in sports history owe some of their career success to the coaches who put them in a position to succeed by helping them prepare and surrounded them with top-tier teammates. These are the teams with the most Hall of Famers.

Coaches cannot implement their desired strategies and culture overnight. It often takes months and even years. While some coaches are given the freedom to do things their way over the course of several seasons, others work for team owners who have little patience. At many of the worst franchises, coaches are under huge pressure to deliver immediate results. These are the teams that always fire their coaches.

Click here to see the greatest coaches of all time.