OMG! Don't know if that was typical of serve mechanics back in the 20s and 30s but it leaves a lot to be desired. Difficult to believe that that Tilden supposedly hit a serve in excess of 160 mph back in 1931 with a wood racket and those mechanics.
Perhaps it was not until Pancho G came along in the 50s and 60s that the modern serve began to take shape (w/o the jump). Sampras in the late 80s or the 90s might have been one of the early pioneers of the left foot landing (for a righty) with the left leg kicking back.
Thnx for the feedback. This might very well be the case. It could be that it took quite while to see significant changes in serve mechanics of most players after the rule change. Players in the 70s had some semblance of leg drive but I don't recall of any players who had enough leg drive to get them off the ground very much. More knee bend with greater leg drive may have come later in the 80s with the likes of of Boris B and Pete S.
When Boris developed his serve as a young lad, the right foot landing was the de facto standard. His serve mechanics was the next step in the evolution of the serve. The Pete Sampras serve, a few years later, was a further advance in the evolution of the modern serve.
Take a gander at the serve of Andre Agassi early in his pro career (at 0:24 in the link below). He lands right foot forward, somewhat like Boris. Compare this to to the Agassi serve in the past decade (and the late 90s?) -- we see that he changed his mechanics -- in particular, he lands on his left foot first rather than his right.
http://www.youtube.com/watch?v=7PF1kfJSia4
.