Hingis attempted an underhand serve to Graf in the 1999 French final, match point.
They booed her. It was an ugly match.
I'm serious ..... why do you think they booed her? Is it crass to try to win? Is an underhanded serve against the rules? I wonder.
Should baseball fans BOO a pitcher who throws a changeup to the plate????
I guess you're not old enough o remember Rip Sewell and his ephus pitch ........LOL!!!
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http://www.baseball-almanac.com/asgbox/yr1944as.shtml