No. 10, Strong Wrists Are Necessary: Long distance hitters like O'Doul know the value of powerful wrists, which give the ball the last extra ounce of drive that sends it over the fence. Many boys who begin with weak wrists develop into strong hitters by constant exercise. One method practiced by major league players is to carry small rubber balls in each side coat pocket (handballs usually) which they continually squeeze as they sit in their hotel rooms or walk along the streets. In time the exercise develops the wrists to the proper degree of strength and allows them to swing a bat with increasing force.