Double Ball

Double Ball

Thoughts on Tennis Doubles Strategy

When playing doubles, there are a few strategies to keep in mind when returning serves and they are described below, however the main thing to remember in doubles play is this: Doubles is won at the net! Playing doubles is a lot of fun. You get to play with a teammate which means you have someone to talk to. Secondly, with two people you really do not have to move as much as you do in singles, which is nice if you are out of shape or lazy. The game is very fast with alot of reflex shots and surprises.

When playing doubles, you must decide what side you will return from. You can either receive from the forehand side or the backhand side. Choosing which player plays on each side can be fairly straight forward if a few things are considered. First off, if you and your partner are both right handed decide who has the worst backhand. Ironically, this player should return from the backhand side. The main reason you want this is that it is much easier for a person to hit a backhand cross court across his body instead of an inside out backhand. The person with the worst backhand should take the easiest backhand, not the easiest forehand. You want to return serve away from the net player, so just about all returns are going to be cross court. If both the players are left handed, put the player with the worst backhand on the deuce court for the same reasons. If you have a mixed righty and lefty, put the righty on the deuce side, and the left on the ad side. This will leave each player with a cross court forehand return across his body which will be a definite advantage.

Even when playing a team with a big server, its possible to break the serving team. You do not need to hit winners on the return, but you do need to be able to place your return in such a way that you are set up for the shot after your return. Taking the most common play by the serving team, the server will serve and rush the net to volley. As the returner you must make a shot that is hard for the serving team to hit. A return down the line, for the most part, does you no good. The guy at the net will not have to move to have an easy volley. A cross court return is a must. Keep the ball low, and try to bounce it around the service line. As the server moves in, he will be on or around the service line when the return comes back.

Try to return the ball at the server's feet. This is not only a difficult volley, but just by the laws of geometry, the server is forced to hit up on the ball. Hitting up on the ball gives your partner at the net an easy volley, and it also gives you an easy  volley when rushing the net. If you are playing a team that likes to poach (switching sides just after the serve) do not panic. Remember to look at the ball. If you are looking at what the other team is doing, you are not looking at the ball and will probably miss it. By the time you are lining up the return, however, the guy at the net will have probably given you some indication of of what the plans are.

At this point you are basically committed to the shot. If you think he is going to poach, rip the return down the line. If you try to do an audible at the last second, you will miss your shot. Get a feel for how things are going, determine where you will place the shot and hit it. After you decide where to go with the return, do not let anything change your mind. Things happen so quickly that any hesitation will cost you the point.

When you hit the return start moving in. Whatever team controls the net will win the match. If you hit the return and stay back, that gives your opponents the opportunity to take the net. If you hit and come in, you will get the net and win. It is also very intimidating for a server to see both opponents rushing the net after he serves. With a good low cross court return you will be in good shape for an easy volley. So hit the return, and then get as close to the net as possible. 

There is a large mental aspect to tennis. As the return team, you are at a disadvantage because you are not starting the point out. But you can intimidate by hitting low cross court returns, rushing the net at any chance, and standing in the middle of the court as you wait for your teammate to return.

About the Author

Double Ball Pin Joint?

Why do we use Double Ball pin Joints ?
I mean why not just a normal joint ? What do the ball do here ?
Like in a boat propeller to transmit the vertical motion of the actuating rod to the rotaing crank arm we use A DOUBLE BALL PIN JOINT .

There are constant velocity joints using one ball and one common centre. As you know a universal joint with two centres (two pins) suffers from variable angular velocity, which increases as the angle of the connected rotating shafts deviate more from straight alignment.

I can only imagine the connecting rod you describe uses two balls with pins to deal with side ways movement as well as the rotating plane and thereby relieve any tendency for side loads. This is my best guess without a sketch.

Double Ball Ornament