Defending the Paint
Power forwards must protect the area directly under and around the basket, called the paint. Their job is to prevent opposing players from getting easy shots close to the rim. They do this by staying in good position, moving laterally to block passing lanes, and using their body to make it difficult for opponents to score.
Shot Blocking and Contesting
A major responsibility is attempting to block shots or at least make opponents uncomfortable when they shoot. Power forwards use their size and jumping ability to contest shots without fouling. Even if they cannot block a shot, making the shooter hesitate or alter their shot can help the team defensively.
Rebounding on Defense
Power forwards must box out opponents and fight for rebounds after shots miss. Grabbing defensive rebounds prevents the other team from getting second chances to score. This requires strength, positioning, and effort to keep opponents away from the ball.
Help and Rotation Defense
When guards or small forwards drive toward the basket, power forwards must help defend by rotating over to slow them down or block their path. After helping, they need to quickly recover to their own player to prevent open three-point shots. This requires good communication and defensive awareness.
Guarding Multiple Player Types
Modern power forwards often defend both traditional big men in the post and more athletic opponents who shoot from outside. They must be versatile enough to handle physical post players while also being able to move laterally and defend players on the perimeter. 
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