If you can hit the lob in the air call "mine" and hit the overhead. If the lob is going to bounce behind you call "yours" and let your partner take it as he will have an easier shot, since he will be angling towards it and will be able to see the other side. You, on the other hand, would have to turn your back, find the ball and get to it but far enough away so you could have a swing. Even if you do all this you will probably still have a blind shot. Remember, if you call "yours", you immediately switch to cover your partners side