I'm currently reading Mr. Nastase. It's evident that the real money in tennis didn't start until after Laver's prime. Really, the real money didn't start until after Nastase's prime. Anyway, Nastase relates several stories about playing in tournaments and having to fly overnight on his day off from say New York to Los Angeles to play World Team Tennis, then having to fly back that night to play the next day in the tournament.
On another occasion, Nastase was playing in Houston and had to fly to South Carolina to play the Pepsi Grand Slam and then back to Houston the next day to finish the other tournament. Nastase relates that he routinely played 25 - 35 tournaments a year. The one thing he does mention is his steadfast devotion to Davis Cup.
The pros back then were trying to maximize their income. When money began to come into the sport, the guys who lived day to day as pros before were intent on making as good a living as they could. I really don't think the majors meant as much to them. Nastase said that he made more money and was in more demand after his best days were behind him. I can only think that Rod Laver enjoyed the same delimma.
The whole major count thing didn't become important until Pete Sampras approached it. Or, the "Career Slam" wasn't important until Agassi achieved it. Or, the clay court win streak that Nadal set, nobody gave Vilas a title when he did it, and nobody gave Borg one when he did it. So, if you look at it in that perspective, for 30 - 40 years of Open tennis, nobody really made big deals out of these type accomplishments. It's only been of late when the money was obscene and the marketing of the ITF and ATP/WTA to increase their exposure came into play.
As to Laver, he played in the WITC event most every year it was held. In some of the interviews, it was pretty clear that he hadn't been playing at all, but the first prize was $50,000, so they definitely had his attention. Borg too played it, I wonder how much it would take to get the top 4 men and top 4 women today, or if there is enough money in the world...
My personal opinion is that the pros back then were more intereted in making a living and bankrolling as much cash as they could. They knew their tennis careers wouldn't go on forever and were like the folks who grew up in the Great Depression when it came to money.
Wilson Six.One 95 16X18 Pacific Natural Gut @ 58
Strung Weight 356g 352g Balance 31.5cm 31.3cm