Because defense wins championships
Although defense is often regarded as the passive side in basketball, this is not the case in competitive play. A good team is able to take initiative on defense and force the offense into doing what they prefer not to, instead of just reacting. This is done through defensive schemes that teams implement, which can play to the weaknesses of their opponents.
Zone: The most commonly-seen defense at many levels of play, this is a basic and cautious form of defense whereby defensive players guard an assigned area. This can take various forms, such as the usual 2-3 zone and the 1-3-1 that targets passing lanes. For the zone defense to succeed, constant communication and good teamwork is required to prevent any lapses. Zone defenses are likely to give up space for outside shots and thus can be effectively employed against poor-shooting teams.
Man-to-man: This is the default defense in the NBA with players assigned to a specific offensive player, regardless of where they are on the floor. This is often used when the defensive team has comparable or superior athleticism as it is an intensive defense that requires speed, strength and conditioning. A tight man-to-man defense can prevent open shots, but leaves the team vulnerable to quick drives due to the lack of spacing, thus requiring timely switches.
Combination: As its name suggests, combination defenses combine the zone and the man-to-man. One good example is the box-and-one, where an outstanding defensive player is assigned to guard the opponents’ star one-on-one, while the other players guard the paint in a ‘box’ formation. This can be effective against a team that is heavily reliant on its best players.
Press: This is a more aggressive style of play where the defense swarms the offensive players to force hasty decisions and a fast pace. This can work against teams with weak ball-handling or passing, especially if your defensive players are lanky or athletic. A variant of the press is the trap, which uses double teams to force the offense towards the baseline, sideline or half-court line.