Martina is so unlike the kinds of threats the modern player sees these days. Especially if the court bounces inconsistent and low. That hook is going to save her bacon on countless occasions until opponents get used to the pancake effect, and the funky low spin and get used to that woman standing at the net waiting for something a little higher she can volley away. Pace alone is not the answer to the Martina question on grass. Modern grass is a different animal, These players can just power that return past Martina before she gets into the net position.I agree, that is another reason I think Serena might have had more trouble with Navratilova than with Graf. She doesnt even play a lot of good lefties, but I seem to recall one from France (dont know her name first hand) who does pretty well vs Serena, and she doesnt even serve and volley or come in a lot, have a true hook or kick lefty serve into the ad side (I may not remember her name but have seen her play numerous times), and of course isnt even close to the caliber of player Navratilova is. Even more in the earlier 2000s when the courts were a lot faster still than they are today.