I have always wondered why do college coaches and major league baseball managers wear lightweight jackets during the summer. I can understand the Sanfrancisco Giants wearing pullovers during a night game. Since the temps often drop off to the 60's at night. Here in the deep south the temps are in the mid 90's during the day. Then at night, around 77 or so. Who wants to wear a pullover? So hopefully all you can help me out with an explanation?