I've read a bit about the crouch defence being a good stance while at the net in doubles to be ready to intercept a smash. However, it's mentioned that this is good for the women in mixed doubles. So my question is, why is this suggested for women and not men? What are the alternatives for men (in both mixed and non-mixed)? thanks.
No-one (woman or man) should attempt crouch defence at the net, unless they are confident that the smash will be very weak. Any strong, steep smash will overpower you, and a flat clear to the empty rear corner will also be effective. Crouch defence works just the same for women and men. It is more effective for the cross-court defender, however; and in mixed doubles the woman should normally take the cross-court defensive position when the opponent is smashing. Normally, you should not commit to a crouch defence posture until after you see the smash. Start with a normal defensive posture, and then change to crouch defence when you see the flat smash coming. However, if you are confident that the smash will be flat (not steep) or very weak, then you can commit early to crouch defence, and maybe even move in to the net. This is hyper-aggressive smash "defence", and only works when the smash has no real venom.
usually you do a crouch defence when you are at the net and your partner hits a bad smash/ bad drop/ weak clear that get intercepted before you realize it was an ugly shot. So then your stuck with little time to retreat from the front of the net, but should crouched low so that your return stroke is overhand. Otherwise, the smash will most likely be right at your face/chest, which is difficult to return.
