Jeff Tesreau, 

 the star pitcher 

 of the Giants, 

 about to baf- 

 fle the bat- 

 ter with his 

 great spitball 



I Underwood and Underwood 



NO definite explanation of the vaga- 

 ries of the spitball or the "shine" 

 ball has ever, so far as I am aware, 

 been given. I have seen many generaliza- 

 tions, but no specific explanation, and so 

 I am now essaying the task in the hope 

 that it may prove interesting, and possibly 

 serviceable, to players of baseball. 



Definite and consistent curves in base- 

 ball, or swerves, as they are called in 

 cricket, can be produced only by spin 

 imparted to the ball by all the fingers 

 and thumb or some of them. 



Comparatively few people know that 

 the "top" of a wheel moves more quickly 

 through the atmosphere than the "bot- 

 tom"; yet this is undoubt- 

 edly so. The reason is that 

 at the "top" of the wheel 

 the motions of revolution 

 and progression "conspire" or 

 coincide. To put it, perhaps, 

 a little moje simply we may 

 say that the wheel is going 

 forward and is rolling for- 

 wardly, therefore at the top 

 we have the sum of these two 

 motions. 



It is otherwise at the bottom of the 

 wheel. Here, as this portion of the wheel 

 is revolving backwardly, the rotary mo- 

 tion conflicts with the progressive motion, 



Spitball Myths 



Why pitched baseballs curve and why 

 the spitballs are scientifically foolish 



By P. A. Vaile 



[Author of "Swerve, or the Flight of the 

 Ball," "Modern Golf," "Modern Tennis") 



and instead of the sum of two motions, 

 we get the difference. Of course all por- 

 tions of the wheel \'iewed as a whole are 

 progressing towards its destination at 

 the same rate. It is merely that certain 

 constantly-changing portions are moving 

 through the atmosphere at different 

 speeds. 



That, shortly, is the whole secret of 

 curve or swerve, for the side of the ball 

 whereon the motions conspire sets up 

 more friction with the air than that on 

 which they conflict. A projectile always 

 seeks the line of least resistance, there- 

 fore the ball is forced over toward the 

 side where the spin is backward. 



I may here repeat that there is, so far 

 as I am aware, absolutely no other means 

 whereby definite and consistent curves 

 with a ball can be obtained. If there be, 

 and anyone can tell us of them, the scien- 

 tific world will be much interested. 



This brings us to a consideration of the 

 spitball and the "shine" ball. Any curve 

 that these balls have is not due to the 

 action of the air on the wet or shiny patch 

 on the ball. 



It is due to the amount of spin that is 

 imparted to them by the pitcher on ac- 

 count of those patches. What finally 

 decides the nature of the spin on any ball 

 must necessarily be the last point of con- 

 tact between the ball and 

 the player. If a ball is 

 held, say, mainly by two 

 fingers and a thumb, and 

 pitched from that hold, the 

 flesh grip of the three engag- 

 ing members may be ap- 

 proximately the same, except 

 for the force of gravity's 

 bearing the ball down on the 

 lowest of the three, and the 

 push of any downward action 

 in the throw. 



Now, suppose that the portion of the 

 ball remote, or farthest away from the 

 lowest engaging member, naturallv. in 



The Spitball 



Spin A to B. Flight D to E. 

 Therefore spin and proRression 

 conspire at portion shaded 

 dark, C. At portion F, the 

 spin is against the progression. 

 Consequetitly, the ball is 

 forced towards F', as there is 

 less friction there than at C 



uoo 



