Played a former D1 player yesterday who still plays a lot of league tennis on a 5.5 team. Wow it was eye opening. Here are the main differences I experienced: Serve -I could handle his serve pretty well, as he wasn't tall and didn't have the angles a taller server would have, and I kept my returns deep, but any return I hit "average" he was immediately dominating the point. On my serve, his returns were all deep and at my feet. And my second serve...forget about it. My 2nd serve is actually decent and spinny, but he crushed it. That caused double faults as I felt I had to hit the ball a lot harder on my 2nd. Groundstrokes: My average shot -decent topspin, medium power, was immediately put away with force. This doesn't happen at 4.5! So I started hitting the ball harder -a lot harder-than I was used to. I could hang for 3 or 4 shots, but then I would either hit long or into the net. He seemed like he could hit these groundies forever. All of them hit with force and deep, even his defensive shots were a foot away from the baseline. Net: He didn't miss a shot at the net. Perfect form on volleys. Also, he passed me, though I think I won about 50% of my shots at net. Fitness: There are no points off when playing someone of this caliber. So you're expending a lot of energy on every point. This has a wearing effect and the UE's started piling up the deeper into the set we played. It was a beating, even though I won the first game with huge flat first serves and putaways on my FH side surprising him. Was happy I got that game, because I didn't even get to deuce on any other game. It was great to get the beat down as a learning experience and makes me see where I need to go. I wasn't overwhelmed and stayed in a lot of points, but it took me absolutely crushing shots just to put myself in position to win a point. Hard to do consistently for a 4.5!