The last couple of days I've been busy putting together a defensive manual for our football team in preparation for the upcoming season and one of the big areas I was researching was the idea of pattern reading. You see, in football most teams that use a zone defense have gone away from straight spot dropping and match receiver routes instead. So, they align in a set zone, say a Cover 2, but then they read the receivers and their movements are dependent on what the receivers do. Now, it sounds like it would impossible to come up with a set of rules to match what the receivers do, but the thing is that receiver movements are highly predictable, because most passing routes are patterned and packaged together into concepts. Therefore, instead of just dropping into your "zone" area and covering grass, defensive backs are instead given a set of rules for a given receiver may do, and the defender reacts to that movement within their "zone" area. Turns out, in basketball, we can apply similar concepts.

In doing my research I came across a chapter in the book by Don Casey called "Own the Zone". It's a pretty good book going through the history of zone defenses in basketball. In the chapter on matchup zones, it talks about legendary high school Indiana coach Bill Green and how he came up with his true matchup zone. He and an assistant were watching a Purdue/Notre Dame football game and thought about creating a zone defense for basketball based on similar rules based on simple offensive player movements.

I had forgotten alot of what I've written in the past couple of years, so I went back through my blog and realized I actually wrote a pretty detailed article on the Bill Green 1-3-1 matchup zone (although I didn't credit it to Bill Green at the time) and it got my brain into overdrive again thinking about the different possibilities of matchup zones.

The original Bill Green matchup zone is based on the principle of dividing the court in 2 halves using the hoopline. The defenders are then assigned:
- a #1 defender on the point,
- a #2 defender takes the first offensive player on the left,
- a #3 defender takes the first offensive player on the right,
- a #4 defender takes the second offensive player on the left or right (the rover)
- a #5 defender takes anyone in the paint or right man high or low

What I did not cover in my original post was the basic matching principle that Bill Green uses, which is based on what the offensive player can do. For you football coaches out there, this will sound very familiar to robber coverage or 2-read. Basically, an offensive player with the ball can only do 1 of 3 things:

1. Shoot. Get a hand up.
2. Dribble drive. Slide and sag.
3. Pass.

An offensive player without the ball can only do 1 of 3 things:

1. Move and replace teammate.
2. Pick.
3. Flash to the basket.

Those are the only 6 things a player can do with or without the ball. On the first 2 with the ball, the defender reactions are universal, they are exactly same for any defense man or zone. On any pass and pick in any matchup zone, you will switch automatically every single time. So really, the rules for defender matchup movements are restricted to 2 movements, replace a teammate, and flash to the basket. All the players have to remember are their original rules. Any movement to replace a teammate is an automatic switch. Any flash to the basket is covered by the same defender. The most complicated movement is any flash or movement through the lane. In this case, the defender passes off their man to the #4 rover and they switch checks. Here are the base formations against offenses that will attempt to align against the matchup zone:

Having this base knowledge, defending flashes to the basket are stated as I wrote in the original article.

The weakness of the 1-3-1 matchup, is obviously the corners. Teams can overload to one side of the floor and now the defense has to break its rules to cover the 4 players on one side.

In order to combat this problem, the #5 switches to take the corner man and #3 (or #2 if overload is on the left) takes the offensive player in the paint.

If you are having a problem with the overload with a player in the corner, Bill Green has a 1-1-3 matchup which is stronger towards the baseline. Instead of using the hoopline as the divider, now there are 2 above the FT line and 3 below. If one of the 3 low players goes above the FT line, the #4 rover carries him above the divider.

I think the problem that most people who play a zone defense is that they just play the spots, they don't even attempt to matchup players. It's the same analogy as football defense, you can't just cover grass, you gotta cover receivers. Same in basketball, you gotta cover players.

For a good video that has a similarly type matchup zone system, check out Flip Saunders' DVD on the 1-2-2 Matchup Zone. Coach Saunders is currently the head coach with the Washington Wizards.