I would always start basketball practice with a question – “What is the purpose of defense?” Players would answer, “steal the ball”, “keep the other team from scoring”, or “stop your man.” I would respond, “The purpose of defense is to get the other team to take the worst possible shot!” You see that if you can get a team to take a bad shot most of the time you will have a chance for a rebound because most bad shots are missed. If therefore you are a good rebounding team every bad shot basically becomes a turnover by your opponent and you have created a turnover while focusing on the most important thing – guarding the nest.
You see in “steal the ball”, “keep the other team from scoring” and “stop your man” your focus is not on the most important thing – the nest. In each case you are either focused on the ball, the scoreboard or the man and not the nest. Just like with bees, the nest is everything. When an intruder tries to get close to the nest we defenders swarm, pushing the intruder away from the nest. As defenders we start at the nest and push out from there, collectively not individually.
Playing defense collectively lends itself to zone principles. I believe even if you intend on playing man to man defense as your primary defense you should start by teaching zone defense. A zone defense when taught well will teach your team the fundamentals of playing team defense. It will teach your team the importance of help side defense and will make them better rebounders because rebounding out of a zone defense takes discipline and floor balance. A zone defense will train your focus on the nest and teach your players the importance of teamwork. When you switch to man to man after playing a zone well your team will by nature help each other and scramble to close out on the back side. Most importantly it will set your focus correctly – on the nest.