From Dick’s book Stuff
Some great plays are made when a player penetrates, jumps off one foot and glides to the basket, and then slam dunks the ball or puts in a little scoop shot or “dumps off” to a teammate for the score. The crowd loves it, and the penetrator gets a great feeling gliding through the air, yet he has probably doomed himself to several upcoming turnovers as a result.
There is nothing wrong with gliding through the air for a layup. But the problem is, once you have been successful off one foot, you are not likely to be able to concentrate well enough to stop on two feet when that is necessary. Since the one-foot jump-and- glide takes less effort and looks more impressive (when it works), a lot of players jump-and-glide all the time and must consequently trade a lot of walking calls, poor passes or charges in exchange for their occasional successes.
You will score (or enable a teammate to score) a higher percentage of your penetrations if you concentrate on crossing the free throw line and coming to a quick stop. Naturally, you have to be prepared to protect the ball because you will draw a crowd, but from inside the lane you can get yourself a very easy shot or you can throw the right pass at the right time. If you jump in the air, you force yourself to make the play before you come down; so, often you have to throw a pass you would rather not throw.
A further advantage of the two-foot stop is that it is usually possible to make a quick decision at the last instant not to stop if the lane opens and you see there is room to take it in for the layup. But if your concentration is on the one-foot jump-and-glide, it is extremely unlikely that you will be able to stop yourself if the opportunity is not there. In other words, by concentrating on the two-foot stop, there is a very real chance that you will still score all the plays off one foot that you would have, but you will reduce the turnovers and forced passes that you would have had by going in off one foot each time.
Two-foot stopping gives you control and enables you to concentrate on getting inside without worry of how you are going to make the shot. That means you should get inside more often once you realize that being there is an objective all by itself. If you can use your dribble and fakes and slashes to penetrate into the lane, you are a good player—if you stop on two feet and make the play. If your habit is to penetrate and glide, then even though you are getting there, you may not be a good player at all. More likely, you are losing a lot of games for your team by doing well against the weak teams and poorly against the good ones.
Remember, this is not to say that you should never go in off one foot. Sometimes you should. But usually your concentration should be on being in control, on two feet, after your penetration. Think: Slash and stop.
From Dick’s book Stuff