Originally Posted by _craze
Sampras isn't hitting topspin in this video. His first volley is a half volley. You generally hit those by following the ball down and up with your racquet and keeping the racquet in front of you. It’s like an infielder in baseball catching a short hop ball. The ball that Sampras hit would likely have a small amount of backspin from the ball bouncing up into the racquet, not topspin. The second volley clearly doesn’t have topspin.
Actually McEnroe used to have a bit of an upward motion on his racquet on low first volleys to his forehand side. He had that funky “racquet head below the handle” form and kind of pulled up on the racquet a bit at contact. But he’s McEnroe. Generally a player would get their body lower for that shot, the racquet would be more level, and there wouldn’t be upward motion.
If you want to try some topspin on your volleys go for it. I just think you’ll have a hard time doing it and you’re missing the fundamental point of volleying, which is accessing sharp angles due to your proximity to the net. Keeping the motion simple, racquet in front, and using your opponent’s pace are keys in accessing those angles, especially when you’re trying to volley a rifled forehand.