when to move up to net in doubles...?

if you are that good with your volleys, then move up anytime...

if your volleys are not that good, then only when your opponents are not able to hit an offensive shot.. (assuming that 1 of you is already at the net...)

it really depends on your volley skills and your opponents shots...

ok well it depends what position you are in. If your partner is Returning and you are right behind the service line, you want to move up to the net as soon as the Return goes past your Opponent at the net. You want to get to the net as soon as possible. It is one of the most powerful places on the court.

hope i helped !

usually if its a decent serve that ur opponent has trouble returning

or

u hit a great angle shot that is tough ur opponent to get, rush up to net to put away their ball that wont be a good hit.

if ur more defensive than offensive then u must be wise about when to go to net

Tennis

When the ball bounces in the service box basically any short ball you need to come in on.