A three-time All-Star who led the American League in ERA twice, Luis Tiant threw six different pitches from three different arm angles, and he never had the exact same delivery for any of them.
Tiant could throw a fastball, curveball, slider, knuckleball, palmball and a slow curve, bringing his arm either over the top, three-quarters or sidearm.
On top of that, Tiant would almost turn around to face second base during his windup, but instead of spinning back around and firing the ball toward home plate in a fluid motion, he'd hesitate, often looking around the park before throwing his pitch.
It made it nearly impossible for batters to figure out what was coming, as they not only couldn't tell what pitch he was throwing, but they had no clue as to what arm angle he was going to use in order to throw it.
Tiant explains when and why he adopted this unusual method of pitching, via StogieGuys.com:
I started my career as a power pitcher who got his fastball up into the 96-98 mph range. After a year off from winterball, which in those days was unheard of for Latino players, I had a dismal ’69 season after a great season in ’68 where I went 21-9 with 1.60 ERA. I was traded to Minnesota from Cleveland and suffered an arm injury, which led to my release. My attempt for a comeback went from the Braves organization to Boston where I ended up resurrecting my career. My loss of velocity made me change my style of pitching, and from that came the development of my unorthodox style in order to keep hitters off balance. The rest is history.