A match-up in basketball is a term used to describe the strengths and weaknesses of two players or teams in how they compare to each other. Match-ups can be measured in terms of performance, skill, build, and ability (e.g. height, speed, and athleticism). For example, a skilled dribbler may be compared to a weak dribbler. A tall center may be compared to a shorter point guard.
Specific match-ups can be analyzed by teams or coaches and be used to the team's advantage. At times during basketball games, teams will notice certain match-ups between players and keep these situations in mind when executing offensive or defensive strategies. If a great scorer is matched-up with a weak defensive player, then this match-up will be exploited.
The term match-up can also be used to describe a specific players defensive assignment in a man-to-man defense. When players "match-up", they choose one player from the opposing team to guard for that game's defensive possessions. Therefore, the player they are tasked with guarding on defense would be their match-up.