Fielding Yost

“ This diagram shows what is commonly known as the Pennsylvania defense. The ends are played in very close to tackle and sent immediately into the opposing interference to break it up or tackle the runner. They will meet the interference before it is under much headway and will often be successful in spoiling the play behind the line. If the ends do not get the runner he will usually be left without interference and can be easily tackled by one of the defensive backs. ”

“ The defensive quarter back, which is being played by the full back, and the left half back have shifted their positions to the right. This would be the position taken by the team if the opposing side were using right tackle back or right tackle over on the line. The men would shift to just the opposite position should the opposing attack demand it. ”

“ Regular Formation - Left Half Back Cross Buck Outside of Right Tackle.
This is in the nature of a quick driving play directly over the position occupied by the defensive right end.
Center blocks opponent to left.
Left Guard goes through, cuts off reinforcements and assists the runner.
Right Guard blocks the opponent to left.
Left Tackle comes around and assists the runner by his interference.
Right Tackle blocks opposing guard and assists in checking opposing tackle.
Left End comes around quickly, watching for a fumble and carries runner forward when tackled. ”