Harrison is also only 20...Querrey is 24. Ryan Harrison isn't anywhere close to his peak potential...where Querrey might have already peaked or at the very least is very close to his peak.
Harrison has the higher potential.
Yep, time will tell...surely at the moment Querrey and Isner are clearly more accomplished. I think Ryan Harrison and Jack Sock have the potential to win a grand slam whereas Isner and Querrey look as if they never will.
Well, that´s true, Isner and Querrey will never win a Grand Slam.
I like Sock, not much Harrison, but at this moment they are really young, in he 80/90 they can`t progress anymore at that age, but now players have peaks at an advance age, so I think Harrison and Sock, (and Harrison brother also) have a lot of credit