From what I remember, Ryan didn't throw a slider either - at least not early (the AL part) in his career. He started out as mostly fastball/curve, and when he couldn't control the curve (which was most of the time), he walked a lot of guys (career OBP against >300). When he could land the curve, it was a no-hitter waiting to happen. Ryan was 33 and back to the NL before the first time he had a walk rate less than 4/9IP.