Here's a great article on the mental side of pitching: "It's just seeing what you want and letting your body take over and do it." This guy doesn't light the gun up, but instead relies on a "deep conviction and confidence in all his pitches." I thought that "conviction in your pitches" was interesting and effective terminology. You got to believe in your stuff! If you do believe in your stuff it is amazing what you can achieve no matter what your arm strength.
Here is the link: http://www.tampabay.com/sports/baseball/rays/article428741.ece