One of the keys to playing good man-to-man defense is being able to see the player you're guarding and the ball at the same time.
This is tricky as you are forced to split your vision while moving around on the court. Learning to take the better angles in relation to the ball and the player you're guarding helps.
So does having great peripheral vision.
Some might be born with a greater range, but Hall of Famer Bill Bradley actually did a drill to improve his peripheral vision.
The beauty of Bradley's training technique is that it doesn't require being in the gym or even having a basketball. It is something that can be built into your every-day routine.
Bradley would walk down the sidewalk looking straight ahead. But as he was doing this, he would concentrate on seeing and identifying objects at the outer edges of his vision.
By doing this and honing his peripheral vision, Bradley became known for having a superior sense of where he was on the court in relation to the basket and the other players.
If you are walking with others, you can turn this drill into a game and figure out who has the better peripheral vision. In either case, sticking with this drill could help make you a seemingly smarter player.