Join Date: Feb 2002
Location: London, England (for now)
Interesting theory, but at the risk of sounding like a broken record...
Hingis beat Monica so frequently because of one major factor that contributed to the others: lack of mobility brought about by lack of fitness.
Their first match was in '96, at a period when Monica had a lingering shoulder injury, was not as fit as her top rivals, and was dealing with lots of personal issues. Still, to a large degree, I believe Seles fooled herself into thinking her level of fitness was sufficient to win slams. Winning the Oz Open in '96 and getting to the final of the US Open that year no doubt bolstered that belief.
But Hingis was fresh, and had a near-supernatural ability to expose players' weaknesses from every corner of the court. If Seles had been able to deal immediately with her fitness issues as soon as Hingis exposed them so readily, their head-to-head might have been different. As it is, Seles was only able to beat Hingis when she was so 'on' that the fitness factor was eliminated (i.e., groundies too powerful and accurate to defend with placement and guile).
Hingis beat Seles by simply placing the ball as far from Seles as possible so often that Monica was drawn into errors of exasperation. In their close three-setters that Monica lost, she simply ran out of gas.
It may be that there was a mental factor at times, but I'll bet it was the knowledge that she simply couldn't track down enough balls that quietly ate at Monica as a match progressed (rather than being psyched out by a particular player).