Jon Cooper has coached the Tampa Bay Lightning since 2013. During that time, he has watched the Battle of Florida between the Bolts and the Florida Panthers go from something theoretical to one of the NHL's most intense feuds.

"They started to get good when we happened to be at the peak. It's been a battle. And I'm telling you, it's so much fun to play games against those guys," Cooper told ESPN. "They for sure circle us on the calendar, as do we."

The lifeblood of the NHL is rivalries. They're the most marketable commodity in the league outside of the Stanley Cup itself. They invigorate the fans as much as they do the players and coaches.

But like success on the ice, rivalries come and go. For example, we're about a dozen years removed from the Chicago Blackhawks and Vancouver Canucks having the most intense and brutal rivalry in the NHL. You'd never know it watching those teams play today.

We last ranked the top team rivalries in the NHL two years ago. Plenty of dynamics have changed since then, although a few feuds remain as intense as ever. So we decided to revisit them as another addition of the Battle of Florida arrives this weekend (6 p.m. ET Saturday, ESPN+/Hulu).