Burger King revamped its playbook. It's working.

Marcin Golba/NurPhoto via Getty ImagesThis post originally appeared in the Business Insider Today newsletter.You can sign up for Business Insider's daily newsletter here.The burger wars are heating up.Burger King's second-quarter US same-store sales jumped 8.5%, while McDonald's growth lagged at 0.8% and Wendy's went backward, falling 7%.It's not just a win for Burger King's new strategy (more on that in a bit). It shows the burger wars are alive and well, writes BI's Alex Bitter.A big reason fo