From what I've read, tennis from the 1800's through the 1930's was primarily a baseline played game. Player rallied until one made an error. Outright winners hit from the baseline were unheard of and seldom if ever seen. Today, they are as common as 130 MPH serves or 120 MPH serves on the women's tour.
The single biggest change to tennis occurred in the 1940s when Jack Kramer "developed" percentage tennis. This new tactic employed cautious baseline play and approach shots designed to get the player to the net. John McEnroe said it best when he said that he viewed S&V as the best way to win a point given the size of a wood racquet and the geometry of being at net. Quite simply, you had more court to hit into.
I will disagree with one thing in the OP. Metal racquets have been around forever and really didn't change the game. Jimmy Connors and the T2000 were viewed as revolutionary and it was the combination or perfect storm of the two that did it. Every other pro at the time tried a T2000. They could hit the ball as hard as Connors, but none could control the ball using that frame.
Likewise, graphite came along and didn't really change the game. There were early graphite frames that were "standard" sized; i.e. they had 67 sq in heads. Among them were the Wilson PWS, Bancroft Scorpion, Fansteel Graphite, Tony Trabert C-6, and Adilla Canon. I own a Trabert C-6 and have hit with most of the others listed. Early graphite frames were very heavy, very stiff, and evenly balanced. The string patterns were just like wood. In short, they were designed to play and swing like wood racquets. There wasn't a big power boost using them.
It wasn't until the Prince Classic, then just known as the Prince, came along. It wasn't all that powerful by today's standard. It was actually very flexible. Wilson followed suit and produced the first Cobra which was a rocket launcher. I demoed one way back then and aside from being told by my mates I was hitting with a women's racquet, I found it very difficult to keep the ball off the back fence.
The development of graphite frames has truly been an evolution. Even as late as the late 80's, graphite frames while larger in head size weren't all that much more powerful. I attribute this again to their weight and balance. While lighter than their predecessors, they weren't like today's frames and the balance point was still more even. The frames had a heavy swing to them. I remember reading a Tennis Magazine article way back then which was documenting the evolution. The first "mid" racquet generation headsize averaged 80 square inches. It seemed to be the de facto standard for all manufacturers. Then, almost as if on queue, everybody went to 90's and then 5 years late again to 95's. Now it seems 95's are destined for relegation to the same place as 90's, as specialty frames. Today, the market is vastly dominated by 98 - 100 sq inch frames. OS frames are as common as 90's it seems.
Anyway, while 80 - 95 sq in racquets were predominant along with their more wood-like weight and balance, S&V tennis dominated. It wasn't until the latest generation of frame came along with more headlight balance, lighter weights, and polyester string that S&V tennis became a thing of the past.
Way back, pundits were astonished the Bjorn Borg could hit outright winners from the baseline with his opponent on the other baseline with a wood racquet. It simply had not been seen. Borg was the first player to routinely hit winners baseline to baseline. Until then, rallies were won by forcing errors.
A whole generation of power baseliners followed Borg. And still, S&V was viable.
Today, S&V is dead mostly due to the refinement of the graphite frame and its ability to be tweaked to the gram in weight and balance. Players can get a frame as light or as heavy as they want. In the days of wood, the only option you had was to drill holes in your racquet as Pancho Gonzalez did in one of his later Wimbledon campaigns. He drilled holes in some of his frames to take out wood to lighten them if the match went long and he found himself tiring. Frames are also measured for flex down to the MM and can be custom built not only for professionals, but for club players. There are racquets today for all levels.
Finally, the string of today as everyone knows, makes a huge difference. The best term I've heard for it is "anti-performance". It takes all the power out of the shot, but provides unheard of spin and control. Where once players used natural gut to power up wood frames, and then used tension to adjust the power (higher tension/lower power), today players are using polyester to deaden their frames and allow them to swing away.
If you look at tennis and racquetball side by side, you can see an eerie parallel. Where once you could watch racquetball on TV and see the ball, now that they have tennis-sized heads, you can't even see the ball. And no one really watches it anymore. Tennis crowds are falling away too.
I do miss wood. You may remember about ten years ago, I posted my year playing league with a Head Vilas. It was fun. The most fun was playing 4.5 with it against kids who were younger than my racquet, had never seen a wood racquet, and then really got p!ssed when they lost. I actually won more than I lost with those. When I watched the U.S. Open last night and saw a women's QF at 7:00 ET and stands that were 1/2 full, it makes me miss wood even more! Tennis has become so one dimensional that it just isn't any fun to watch the pros play.
