What attributes are needed for good defending skills?

Height

So you can defend tall shooters

So you can get the rebounds from the goal

The ability to jump high

Rebounds

Marking your opponent

Stamina

To keep on jumping and marking throughout the whole game

To help get the ball down to the attacking end

Communication skills with other defenders

In case one of you gets injured of can't get there in time the other can take over

Subtopic

Balance

Catching the rebounds near the back line

Being careful not to go offside