In Sun Tzu's The Art of War
, surprise or, more specifically, innovation, has a very specific role. You use it at the right time to change momentum. When a standard move works, doing what is expected never changes momentum. For example, in the current presidential campaign, no attack on the opposition, no matter how effective, is going to change momentum because such attacks are expected.
What kind of surprises could the candidates use? Well, McCain could come up with a surprising choice of VP candidate, which is why people are talking about the possible choice of Joe Lieberman. A Democrat on a Republican ticket would be very surprising, but it also wouldn't work because the first Warrior's Rule is that a team must share the same core philosophy and, beyond their agreement on national defense, McCain and Lieberman have very different philosophies. If surprise is the goal, McCain should choose Sarah Palin, the Republican governor of Alaska. She hasn't gotten a lot of press, but what makes her so unusual is how attractive she is. This is a surprising image for any political candidate and especially for a Republican. If I were McCain, I would announce this choice right before the Democrat convention so that all the Obama people could get on record attacking a beautify, intelligent, successful, woman with more executive experience than either Obama or McCain in front of all those Hillary supporters because she is a Republican.