When you cross so far into your partner’s side of the court to retrieve a lob or to poach that you can’t get back to your side in time, both players can switch positions. To make it clear to a partner that a switch is to take place, someone can yell “SWITCH.” But who should say it? Should it be the one who instigated the switch, or the other, indicating that s/he is going to go ahead and switch sides?
It should be the one who instigated the switch. This is because the one who poached severely, or ran back for a lob, may have time to get back in position, and so a switch won’t be necessary. The partner is not easily able to detect whether the switch is to take place or not. If the non-instigating partner makes the call, it may confuse or slow down the instigator. It will also make it necessary to carry out the switch, even if the instigator didn’t intend it.
If you are working with beginning players, a better call is “Switch Sides.” Just saying “switch” may something they don’t understand yet, or they may be slow to understand exactly what you mean, while the instruction “switch sides” is very clear.
Sometimes players on a well-oiled team will switch silently. As a player becomes aware of the partner moving into the other side of the court, the player simply covers the territory left open. Still, saying “switch” makes it more clear and more likely to work out properly.