Incurve

According to The New Dickson Baseball Dictionary, the incurve was the “pitch now known as a screwball.” ❋ Bill James Rob Neyer (2004)

A so-called incurve is nothing more than a ball thrown in a natural way with great force. ❋ Bill James Rob Neyer (2004)

One might assume that the incurve is simply the reverse of the outcurve, which would be the reverse of the curveball … which is to say, a screwball. ❋ Bill James Rob Neyer (2004)

In a 1908 instructional book called How to Pitch, Bill Dineen says of the incurve/inshoot he used the terms interchangeably, “Speed is necessary for an inshoot … Do not become discouraged if you fail to see the ball positively change its course as it does in an outcurve … Practice will succeed in giving a sharp break to the ball, which may not amount to more than an inch or two …” ❋ Bill James Rob Neyer (2004)

Or “incurve,” a term commonly used as the nineteenth century became the twentieth. ❋ Bill James Rob Neyer (2004)

The language of the game changes substantially in every generation; a rising fastball becomes a four-seam fastball which becomes a four-seamer, a forkball becomes a split-fingered fastball which becomes a splitter, a drop curve becomes an overhand curve which becomes a 12-to-6 curve, an incurve becomes a fadeaway, a fadeaway becomes a screwball, and now almost nobody throws a screwball but people throw a circle change-up that does the same thing, sort of. ❋ Bill James Rob Neyer (2004)

The blade is two-edged, widening from a sharp point to two shoulders from 3 to 4 centimeters apart, whence the edges incurve gradually and finally end in two projecting spurs 3 or 4 centimeters apart. ❋ John M. Garvan (N/A)

It developed presently, that this was now his intention and that the Rube knew it and pitched him the one ball which is almost impos - sible to bunt -- a high incurve, over the inside corner. ❋ Unknown (1915)