Sweeping a playoff series is hard; the opponent is a playoff team too, which means they're pretty good. So is beating one team nine times in a row; laws of diminishing returns and probability indexes and all that. Also, not easy is winning back-to-back games; nobody particularly enjoys having to play back-to-back. Winning a game under any circumstances is extremely difficult when you don't play very well; the Lightning did not play very well Thursday night. They didn't play that well in Wednesday night's Game 3 win either but hoping to hang around long enough to "steal" a game is not a strategy that is going to yield positive results most of the time.