Negro Leagues (1934–1950)
Leon Day
He cocked it at his ear and threw
Partially documented
Day was the rare Negro Leagues ace whose deception lived in his delivery rather than a signature breaking ball — a short-arm, no-windup motion that gave hitters almost nothing to time. A Hall of Famer by 1995, he is remembered for how little he announced himself, on the mound and off. The exact grip behind the heat did not survive.
What it was
A blazing fastball delivered from a short-arm, no-windup motion — he essentially cocked the ball at his ear and threw, a delivery he traced to throwing from second base.
Why it is lost
The biography documents the delivery and a general fastball-curve-changeup mix but no grip-level technical detail; the mechanics that made it work are described, not diagrammed.
The surviving record
A teammate remembered the fastball as genuinely overpowering, set off by a strong curveball.
Attributed to Larry Doby in the SABR biography; a contemporary teammate's impression of the heat from an era without radar, kept as a read of the pitch rather than a measured figure.
Between starts he played the field, including center field, well enough that teammates rated his glove with the regulars.
Based on Monte Irvin's recollection as quoted by SABR.
Every line here is what the recovered record can actually support, labeled by its source and its confidence. Where the legend says more than the record can prove, the gap is shown, not filled.