Do the Yankees play better when they play the Red Sox?

As I sat in my living room watching the Yankees and the Red Sox grind another great game out, the thought entered my mind, “why do both the Yankees and the Red Sox play better when they play each other?” It seems to not matter what record or problems either team is having with the rest of the league-- when they play each other it's as if the rest of the league doesn't even exist. They each manage to play to their highest level and play incredibly competitive (and long) games. Just like this relationship between the Yankees and the Red Sox, I can think of times in my experience in healthcare where having a high quality competitor improved our healthcare facility’s performance. Do you have a competitor who challenges you to greatness? In almost every organization I have been involved with in healthcare, when we had a strong competitor it made us perform better. There seems to be something about competition that brings out the best in our performance. Who is your great competitor, and in what ways do they challenge you to better performance?