David Zalubowski/Associated Press

It has been said of any number of top-flight NBA defenders over the years: "He can guard all five positions." Warriors forward Draymond Green is among them, with one exception—he not only can, he does, sometimes in the same game.

Exactly how does a 6'7", 229-pound forward with average NBA foot speed and leaping ability make life miserable for point guards as explosive as Russell Westbrook and centers as mammoth as DeMarcus Cousins and everyone in between? A 7'1" wingspan certainly helps, but his success has far more to do with his wits than with his reach.

Green's preparation begins with keeping a mental list of where every top scorer wants to get the ball and what he wants to do with it in those last-minute situations.

"It's the most predictable time of the game," Green says. "You know who a team wants to go to, and you know that guy is trying to go score. During the course of the game, a player is looking to pass, screen, he's diving and rolling or slipping the screen, but at the end of the game he's trying to score, that's it. He's got to go score or the game is over."

Whether he's watching a specific prepared video of a player or a game on TV, he's memorizing every scorer's favorite go-to moves and plotting the best way to disrupt them. "When it's for all the marbles, they want to get to their best moves," he says.

The first task is to prevent the scorer from getting the ball in his sweet spot, even if it's only a difference of a few feet. Then, if a player has more than one move, Green positions himself to force the player into the one he wants him to make. If he finds a particular tactic that works early in the game, he may not use it again until the game is on the line.

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"A guy hasn't had time over the course of that game to adjust to it because you haven't done it again," he says. "Probably forgot you did it in the first five plays. He won't remember by the fourth quarter, that's for sure."

Green also knows that a scorer in a one-on-one situation must expose the ball at some point to get off his shot. Watching film helps him determine where and when that usually is.

"During the course of a game, you can't get it every time because no one's reaction time is that quick," he says. "You can't risk getting called for a foul that much throughout the course of the game either. But on the last play, you know the guy is always going to show you the ball. It always helps when we're up two points because if I do foul going for the steal they get two free throws and we can still get the ball back and just go score again."

There is also the job of defending the first 46 minutes of the game. Green can't apply any of these last-minute tactics if foul trouble has him on the bench or playing cautiously to avoid fouling out. That's why his "No. 1 general rule" is to limit himself to no more than one foul in the first half.

"Fouling early will change your whole defensive mindset," he says. "You can't take the same chances or be as aggressive."

So exactly how do his specific tactics change when he's facing, say, a small forward in LeBron James versus a point guard like Westbrook? Pull up a chair and sharpen your pencil. Class is in session, and Professor Green is at the lectern.

Defending Russell Westbrook

Jeff Chiu/Associated Press

"I see Russ a lot. The way I like to defend Russell is sometimes I like to sit back and make him shoot jump shots and sometimes activate and force him to go to the rim.

"As crazy as that sounds—most people would say, 'Why would you send Russell to the rim? That's what he wants to do.' [And it's true] the best thing about Russell's game is not his jump shot. If you're going to pick any shot for Russell Westbrook to take, it's his jump shot.

"That being said, when you think that way, the tendency is to sit back. But when you sit back, you allow him to get comfortable and then he just picks you apart. I'm a firm believer you definitely mix that in and use sitting back to your advantage, but you've got to activate and pressure sometimes to keep [him] off-balance and not let him get in his comfort zone.

"He has a hop into that pull-up jump shot; he takes these tiny steps and then a hop. You can definitely read it a little bit. That being said, it's still tough to stop. But you can get a jump on it."

Defending James Harden

Ronald Martinez/Associated Press

"No. 1, take his space away. There are certain guys in the league that get their rhythm off their dribble. He's one of those guys. The more you just let him dribble, dribble, dribble, the more into his rhythm he gets. The more rhythm he gets…look, the chances of you stopping a player like that is already slim.

"Once you let him dance, dance, dance and get that rhythm, that slim chance is cut in half. At that point it's just a matter of whether he misses the shot or not. So crowd his space, but don't use your hands. That's why I have my hands way out [to my side] because he's tricky.

"If you put your hand in there just a little bit, James has got you. One, he's mastered getting the foul, and two, he gets the benefit of the doubt, so if it looks like it's a foul, it's going to be a foul. It's just like anything else in this league: When you develop a certain reputation for something, you're going to get the benefit of the doubt, good or bad.

"Honestly, I don't think he's a point guard or a shooting guard. I think it's disrespectful to his game to call him a point guard or a 2, because you're limiting what he does. He's a combo.

"So many times we want to make it out to be one or the other. That's why the league is where it is today—because guys aren't pigeonholed into spots. So what you end up getting is more excitement. … It used to be, 'This guy is in there to box out, this guy is in there to spot up and shoot, this guy is in there to drive and pass the ball.'

"It's not that way anymore."

Defending DeMarcus Cousins

Rich Pedroncelli/Associated Press

"DeMarcus is one of the rare persons or talents who can do it from the block, from the wing, shoot the three, dribble the ball. But for me with DeMarcus, the further out he is, the more to my advantage it is. The closer he is to the rim, the more I'm f--ked. And so my whole thing is to force the catch further out, and now it's just mano a mano.

"He's going to go into his move and I'm going to try to stop him, but my foot speed is much faster than his, so the further out I get him, the more I can use my quickness as opposed to him on the block. He's four inches taller than me, he probably outweighs me by at least 40 pounds. I'm already at a disadvantage just by the size. My thing is to force him out as far as I can so I use more of my strengths as opposed to trying to stop what he's incredibly good at.

"One thing I've always been taught at the defensive end is you hit first. In life, you throw the first punch, you don't get punched first. It's the same on defense: You've got to hit first. Do your work early. That's what I was always taught. If you don't do your work early, you're done.

"With him, you're literally working on him the entire possession. Because if he gets you with two feet in the paint, you're dead. You have to foul. You're dead. So for me it's about hitting him early to make him work to get to where he's trying to go. Then once he gets to where he wants to post up, now I'm on the top side, three-quartering, maybe fronting him a little.

"One thing about a guy like that: He wants the ball, and their team is going to do whatever they have to do to get him the ball. The idea is to force the pass to come to him a little further out than he wants, because if it means he has to step further out to get the ball, that's what he is going to do.

"I know that going in, so I just try to do all the work that I can beforehand to make him catch it further out."

Defending LaMarcus Aldridge

Marcio Jose Sanchez/Associated Press

"Completely different player. His go-to shot is a turnaround jump shot. Most people you want taking a turnaround jump shot. He's got a right-hand jump hook over the left shoulder and a turnaround jumper over the right shoulder.

"LaMarcus isn't going to fight you for position. If you push him out he'll let you push him out and then go to his move. With him, I'm still forcing him out because once again I'm giving up four inches. So giving up those four inches, I can't just let guys get into a deep post, because all they have to do is turn and score over me.

"With him, I'm forcing him out; at this point it's just about being a pest. Bring the ball down, I'm all over you. Put the ball on the floor, I'm all over that. And then make him take a tough, contested shot. That's always my mindset with him.

"You know what moves he wants to go to, but you're probably not going to block his shot, so just try to make him alter it a little bit more than he wants to."

Defending LeBron James

Tony Dejak/Associated Press

"With LeBron, obviously it's different because he does so much. It's about mixing it up. You can't always pick LeBron up and pressure him, but you can't always sit back. You've got to do both.

"So with him, as a defender, one possession you're playing him one way, the next possession you're playing him a completely different way, and you just try to keep him off-balance as much as you can. Give him a steady diet of one thing, he'll pick that s--t apart. He's one of the smartest players to ever play the game."

Professor Green won't say it, so we will: Takes one to know one. Class dismissed.

Ric Bucher covers the NBA for Bleacher Report. Follow him on Twitter: @RicBucher.