We all know Nadal's crazy footspeed, so excellently showcased in the AO final this year against Federer. His ability to get to balls that other players wouldn't even think of trying to get to is absolutely amazing as we all know. And we mustn't forget Borg. He was the pioneer. The first real speed demon. His running down of shots everyone else would have left was amazing, even compared to nowadays standards. Yet for me, Chang was the most outstanding of the 3. I think this may be because he lacked the heavy topspin and variety that Borg and Nadal had, and just relied on footspeed alone. His calf muscles were famously huge for such a short guy, and his running ability was unmatched in his era. So here we have three excellent competitors for the title of Speed Demon King, the fastest (in footspeed) player of all time. And now it is up to you to choose who you think deserves the title of Speed Demon King and why.