LOL. You can have all the versatility in the world but if you don't know what shot to use when, you have ZERO tennis IQ.
That's nice, but doesn't really address anything I said.
Did you even read what I wrote or just go on a pointless rant about what you think I said?
I could ask the same question.
Maybe you should tell us what you think tennis IQ is, although I think it's already pretty clear what your basic understanding is: the one who wins the most.
Tennis IQ is playing the best shot you can, which includes footwork, training, rest periods, sleep, diet, scouting, and all the other things.
Tennis IQ is not hitting a lot of different shots if that is less statistically effective for you than hitting with less variety. It is also not abandoning your strengths simply because you're losing at that moment. You complained about Graf not changing her game plan enough, but I recall that being intractable is what led to Hingis' meltdown at the FO in '99 (the bad call just pushed her over the edge). It is precisely Graf's refusal to let Hingis' lead rattle her and get her to change her tactics dramatically (which would have likely failed) that led to her winning the match. The same case can be made for other matches she managed to squeak out of.
Generally, trickery is only needed by players who are playing with a handicap or who are really evenly matched. Martina's advanced age (and serve/volley game to a smaller degree) handicapped her when she played Seles in Paris in '93. As a result, she had to rely more on things like drop shots and long patient baseline rallies which is a riskier proposition.
Playing simple tennis is playing smarter tennis if that simple style gets you more victories. Federer made the same comment, saying that one of the marks of his youthful inexperience was going for the flashy shots instead of the more dependable ones. He said that the key to his dominance was to play the numbers. I think that point is a bit overstated, though, since he was known for hitting flashy shots during his dominance.
At the same time, cat and mouse and other examples of careful strategic plotting can be the key to giving a player the small edge they need. It really depends on the people playing, the conditions, and so on. Players who can't adapt to high wind, for instance, should be able to adapt. But, if a player spends so much time trying to be versatile for every situation and never really hones their strengths for normal conditions that can be a drawback.
Players can also overthink while on the court. There is often a lot to be said for simplicity.