2. Owning the Play at Five on Five
Through games three and four in Tampa, the Lightning outscored the Rangers 5-0 at five-on-five. All three Ranger goals in the two games came on the powerplay. Yes, they obviously still count just the same but the team who plays better at five-on-five typically always wins over the course of a seven-game series.
You have to be able to score at five-on-five in the playoffs. There is no way around it. If the Lightning continue to defend the way they have and limit the chances for a hot Ranger powerplay, the Lightning already have their path to victory.