Basically, there are three types of Person-to-Person defenses: Straight, switching and sagging. The specific type used in a game primarily depends on a team's player personnel. Here are three types of person-to person defenses:
Straight person-to-person is an aggressive defense which causes severe problems to good spot up shooters and poor ball handlers. In this type of defense, defenders will fight over screens. However, it can be susceptible to dribble penetration and on ball screens.
The ability to attack passing lanes make switching person-to-person defenses an ideal defense to use against motion type offenses. In this type of defense, defenders will aggressively switch on all contact screens. The disadvantage to switching is that, in some cases, it can cause severe mismatches.
Sagging person-to-person defense can be very successful against poor outside shooting teams and against dribble penetration. In this type of defense, the defenders will go behind or switch most screens. However, it is susceptible to good outside shooting teams.
The next type of defense to look into is zone defense.