The trick to a good black and white is making sure that you have pure blacks and pure whites and still maintaining texture and detail. If your whites go too far, they will be blown out. If your blacks go too far they will look abysmal.
The three photo's here are examples of BAD, BETTER, and BEST. In that order.
The first image, the back ground is almost hiding the players because of the similarity in contrast. To fix this, when in editing mode, make sure to have a layer fix for the back ground, a layer fix for the foreground, and a layer fix for the players.
The second image is getting there.
It doesn't matter where the pure blacks and whites are in the image, but again, it is important to have texture. The white blob in the background is blown out, probably a reflection on a sign from the Sun. Her hair is abysmal.
The last image is best because, you see pure whites with texture, and even though the blacks are really dark, you can still make out detail.