Mariano Rivers looks harder to hit than Pedro Martinez. He throws one pitch and no one can zero in on it. Every hit I see him give up is hit from a defensive swing.
The most unhittable pitcher I have ever seen over one full season was the most unhittable ever: Bob Gibson in 1968.
The most hittable pitcher with a major league arm had to be Heathcliff Slocum. He had a hundred mile an hour drainpipe fastball. There is another guy whose name escapes me that Ken Harrelson used to talk about that threw at a hundred miles an hour in the minors back in the 1960s, but never made it above double A. I don't know if he was hittable or if he just never found the strike zone.
Nolan Ryan at twilight might have been the most unhittable ever. I once saw his stats for twilight starts and they were unreal. Ryan was the greatest .500 pitcher ever. When he left his team as a free agent after going 16-14, his manager was asked how he'd ever replace such a pitcher and he said, "I'll just get two guys to go eight and seven."
