Steve Lang -
I played high school & college tennis in the 1960's and owned a tennis shop for 4 years in the 1970's, so my history with the game goes back 60 years or so. At the risk of hijacking this thread further, here are some thoughts of how the game has changed over this period.
Surfaces - 3 of the 4 major championships (and the tournaments leading up to those championships) were played on grass courts up until 1970 or so. Very little top-class tennis was played on paved or artificial surfaces, other than on the west coast. Now only one major is played on grass. 2 of the majors are played on paved courts. Grass courts produce low, skidding and some times erratic bounces, so it made a lot of sense to serve & volley rather than play from the back court. Paved courts produce higher, more consistent bounces allowing players to make bigger, more aggressive swings from the back court, because they know how high the ball will bounce.
Grips & Strokes - Two-handed backhands were very rare in the 1960's. I think Bjorn Borg and Chris Evert were the first 2 players to win major tournaments hitting two-handed backhands. Now one-handed backhands are pretty much the exception and two-handed backhands are the norm. A few top men still hit one-handers, but I cannot think of a top woman who does. Forehands used to be hit with an Eastern or Continental grip that produced a flowing stroke. Now forehands are hit with Western or extreme Western grips that enable players to hit with far more topspin. The modern forehand stroke is more of a flick at the ball, like a table-tennis shot. However, trying to volley with a two-hand backhand grip or a Western forehand grip is not easy to do, which is one reason why so few modern players come to the net.
Racket & Strings - Rackets changed from wood to metal to fiber-composite. Like big-headed drivers, the new frames have bigger sweet spots, which provide a bigger margin for error. The new frames, combined with changes in strings, allow players to produce far more topspin on their shots, which allows groundstrokes to be hit much harder than in the past.
Being able to hit so much more topspin, coupled with the changes mention above, means tennis is now played primarily from the back court. As serve & volley tennis is pretty much extinct, points last far longer than they used to.
I hope that provides some context for my claim. I could go on further, but I would start to sound even more like a grumpy old man.
DT