Its an interesting question, if and how we should evalute those special events. I am generally no friend of these 4 men events, but some like the Pepsi Grand Slam had good competition and high prize money. From the early years of open tennis 1968 and 1969, we could look at the BBC 2 event at Wembley in London. It had not the field of the more famous London pro or later British Covered Court at Wembley, but one of the highest first prize money in those years. And its history reached back to 1964, when it was called Golden Racket.
urban, mine is just an attempt to list the richest special events of that period.
Obviously, each poster may not consider it, giving it no value, or giving it a very low value or giving it value.
I believe that it is right to bring those tournaments to the attention then everyone is free to think of it as he wishes.
My considerations:
1) the winners and runner-ups (and often also the semifinalists) are top dogs precisely because the best in the world took part in those events;
2) it was rare that Laver, Rosewall, Newk, Borg, Connors, Mac, Lendl would not win. If the top dogs weren't busy ... Gorman would have beaten Laver and Teltscher would have beaten Borg;
3) I am aware that 4-men tournaments are not recognized but often 4 of the top 10 and the top 3 in the world participated.
Was the BBC 2 event at Wembley in London very rich in 1968 and 1969? I'll do some research to see if I can add it.