If you are a character loyalist, I think you have a better chance of winning in most circumstances. It does of course help to main a top tier character, but when you stick to a main you begin to develop instincts and great MU knowledge. There are VERY few people in this community that can have success with multiple characters (pretty much only the Terry brothers as far as I know). I know pretty much all of the cast since I use Shang but I do struggle sometimes when playing a different character, even if they are technically better than Shang. I will continue to play ST because he gives me my BEST chance at winning due to the amount of time that I have put into him. Future tournaments will probably back up my theory, with a few rare exceptions. People that switch characters too often will probably not do better than those who stick to one.