In basketball you need to constantly have your head on a swivel. You need to be able to see the court not only on offense but defense too. It’s like a game of chess, you need to be able to see and think 2-3 moves ahead. Example: If he drives, I’ll step on here. If he passes I’ll close out. If I get beat, I’ll turn, run, and recover. If the ball goes to the wing I need to slide over and take the charge . You need to know where your man is as well as the ball at all times. You see it happen (read the play), you react or change what you’re doing (move, slide, help), then you adjust to what happens next (let the play unfold and change as needed). Don’t be a reactive player, be proactive. Watch film, study games, and know what’s coming before it happens!