Re: Which players have the highest 'TENNIS' IQ?
Hingis, and current Serena are a few that come to mind.
Radwanska is smarter than most players, but I don't think she's brilliant. Just because you use drop shots and are underpowered does not mean you have a high tennis IQ.
I totally agree re Radwanska. Having good anticipation and playing some tricky surprise shots is far from anything related to Tennis IQ. Plus there's numerous occasions on which she makes questionable decisions, like my earlier example of her serving into Azarenka's BH so much when they play. Anyone with decent tennis knowledge would know you have to avoid the Azarenka BH ROS.
Hingis is the only right winner here.