We talked about lucrative local TV rights yesterday. Let’s talk national: ESPN just agreed to pay Major League Baseball nearly double what it’s paying now to keep baseball rights through 2021:

ESPN has agreed to a deal that locks down MLB rights into the next decade, according to several sources. The eight-year deal is worth $5.6B (an average of $700M per year), approximately doubling the nearly $306M ESPN currently pays MLB every year for domestic TV rights.

That includes digital, radio and, for the first time, the playoffs: one wild card game. Otherwise the deal is basically the same: Sunday Night Baseball and Monday and Wednesday night games.

The current deals with ESPN, Fox and TBS are in place through the end of the 2013 season. As the New York Times reported in July, there is a frenzy afoot, with those three outlets still wanting to keep their games, plus NBC wanting to get in on the action. Clearly those remaining will be in frenzied bidding for the Saturday and Sunday afternoon games, the postseason and any other national products that may be added over and above what exists now.

That’s a recipe for skyrocketing rights fees. And we just saw the first rocket launched.

UPDATE: Putting this money in perspective. Short version: windfall.