East can shift, but the defense only makes four tricks.

She would have had to work a little to make 10 tricks.

After a heart lead South made 12 tricks, although the defense missed a chance to hold him to 11.

It was possible to make 12 tricks with any defense.

Even looking at the four hands, there is no obvious way to make 12 tricks.

These all offer about a 50 percent chance of making three tricks and losing one.

Sometimes it is easier to make 12 tricks than 11.

He would probably make 11 tricks, but might win 12.

South had no way to make more than eight tricks for down one.

It seemed quite likely that somebody could make 13 tricks.