"TALK!!!!!" How many times have you ever said that to your team? I'm guessing you have all had your blood pressure rise because a player or players on your team neglected to talk on defense. Communication on defense is just as important as a team's ability to guard the ball, box out, or getting to proper help position.
If you want your players to talk then you have to do more than ask them to talk. You have to put your team in practice situations where they are required to talk to be successful. The more you do this, the more they do it naturally. Eventually it will become second nature with your players.
Below are some simple, yet effective, drills to use that will help promote communication with your players on the defensive end of the floor.
Play 3-on-2, 4-on-3, or 5-on-4. You can do this in half court or full court situations. These drills put the defense at a tremendous disadvantage because they have one less player than the offense. Remind your players because of the disadvantage not to be discouraged on defense if the offense has success from time to time. In these drills you need to require your players to call out "ball!" when they are on the ball, "help!" when they are in help position, and "deny!" if they are in a denial position (or "gap" if you play a gap control defense).
BALL SCREEN DEFENSE DRILLS
There are several ways to defend ball screens. No matter what your philosophy is on defending ball screens you will need your players to talk on defense. You can do simple 2-on-2 drills where the offense must set ball screens while the defense defends them the way you require. Players must call out the screen and side it is being set on. Also, if you are trapping the dribbler you will need a buzz word the players will call out to signify the defense on the screen. Example: "Hot!" If your philosophy is to hedge on the dribbler, you may also want a buzz word for that to signify and remind the defenders what they are doing. Example: "Bump!"
Another good ball screen defense drill is to play cut throat at one basket. You can set a rule that when the team is on offense they must set ball screens. This will give the defense many opportunities to communicate and work on their ball screen defense.
These are just a few ways to help promote communication amongst your team when they are on defense. The more your players talk, the more aware they are. And the more aware they are, the tougher it is for your opponent to score.