A random break is a breaking format where teams (or slots) are assigned randomly to participants after all spots are sold. You buy a spot, and then a randomizer determines which team you get. It's the luck of the draw before the packs even get opened.
Random breaks are popular because they keep things fair and unpredictable. Nobody gets to cherry-pick the hot team — you might land the Yankees or you might land the Marlins. That randomness adds an extra layer of excitement and keeps pricing uniform across all spots.
If you like the thrill of not knowing what you're going to get until the very last second, random breaks are your format.