Your shot chart is lying to you (and what to do about it)

The Hypothetical Scenario that Really Happens Every Season

Here is a hypothetical scenario for you coaches.

Say it is halftime and you are down by 8 points. The defense has been collapsing on your normally dominate center in the low post, rendering him ineffective so far.

As you look for ways to give him space to operate, you look at the shot chart and notice that your point guard is 3 of 5 from the arc (60%).

shotchart01

60% is a great shooting percentage from downtown, so you turn to your point guard and say, “You are hot from the arc so keep shooting 3s. We need to stretch the defense so we can get the ball to our center.”

That is totally reasonable advice given the shot chart, right? So the 2nd half starts, and your point guard dribbles the ball to the arc looking to pull up and shoot a 3 rather than pass in to the post.

The only problem is, your shot chart was lying to you.

Let’s look at that same shot chart, but this time add how the shots were created.

shotcreationchart01

When you add shot creation to the shot chart, you see that the 2 misses your guard had in the first half were shots taken off the dribble, and the 3-pointers he made were “catch and shoot” shots created by spotting up for a kick out from the swarmed post player.

In other words, thanks to your shot chart, you just unwittingly told your point guard to do the exact opposite of what he should be doing.

Rather than looking to bring the ball down and shoot, he should be looking to pass it into the post then spot up.

How shots are created is one of the most important aspects of coaching, and one of the most overlooked.

Before we get deeper into shot creation, let’s lay the foundation with the terminology for shot locations.

Shot Locations

nbashotanalysisRecently NBA.com has taken an approach to mapping shots startlingly similar to what I’ve been using since the mid 1990s. They divide the floor into A, B, C, D and E shots. (My old shot chart was identical, except that I classified all 3s as D).

I like the NBA’s shot map except that it fails to tell us:

1. When shots come from the baseline, and

2. When shots are very long 2s near the arc.

I believe there is an area of the floor where the shot quality is so low that teams should just keep hunting for a better shot rather than shoot from that space. In an effort to make this undesirable area clear to my players (and their parents), for awhile I referred to the gray area as “C-” space.

basketballogyshotchart1bI don’t call it “C-” space anymore though. Instead I’ve divided the floor up in a way which is much more practical for stat keeping:

The Middle of the Floor
A = Within 6 feet of the rim
B = The rest of the key
C = The free throw line to the arc

The Wings
D = The baseline
E = Midrange 2s
F = The area 1 step within the arc

The 3-pointers
G = Corner 3s
H = 3s everywhere else

When I was young, I used to say that the stupidest shot in basketball is a 2-pointer at the 3-point line: it is the lowest possible percentage 2-point shot you can take. However, I now know that the stupidest shot in basketball is a contested shot taken near the 3-point line, in F space. (We’ll talk more about what contesting a shot does to a player’s percentage in a moment.)

That means your offense should never settle for a F shot unless it absolutely has to in order to beat a shot or a game clock. Of course there are players with skills that challenge the odds on F shots, but on average this is sound advice.

Parenthetically, on defense I teach my players how to bait our opponents into shooting F shots; then when the shooter is committed to the shot we close out hard, grab the rebound and run.

As I have written before, a turnover is a best case scenario for a defense, however you can usually only create a turnover maybe once every 10 possessions. The other 90% of the time, a defense needs to focus on leading its opponent to a poor quality shot then securing the rebound. What you certainly do not want to do is over-guard a player with the ball in F space and force him to move the ball to a better shot opportunity. If you have the ball in a back pocket, your defense is succeeding. Don’t get greedy.

By the way, most fans and some coaches look for evidence of good defense in the box score, things like blocks and steals. The more dependable indicators of a good defense can be found in where shots were taken from, how they were created, and how much time was left on the shot clock when shots were taken.

Revisiting Sandy Weis

In my article Unattended Cutters, I talked about Sandy Weil‘s presentation at MIT’s 2011 Sloan Sports Analytics conference and practically applied it to the Read and React Offense (RRO). Weil’s group used sophisticated motion tracking software to in effect “paint” each NBA player on the floor, then record data on their movements as they played real NBA games. Analyzing real world play, they had 3 major findings:

1. Shooting percentages drop 1 point for ever 1.5 feet the shooter is from the basket.
2. Shooting percentages drop 12 points (e.g. from 50% to 38%) when a shot is contested.
3. Catch and shoot shots are the most efficient, and contesting them doesn’t drop their percentages.

I need to emphasize that those 3 findings are not opinions. They are not theories. And they are not subjective. They are hard data obtained by tracking hundreds of NBA players with computer software programmed to “watch” all 10 NBA players on the floor at the same time and document the outcomes of various behaviors.

Interestingly, of these 3 findings, only Finding #1 can be tracked with a shot chart, which is why our shot charts sometimes lie to us. To track shot creation, we need a different tool.

Shot selection: shot location vs. shot creation

There is an old saying in business that the 3 secrets to success in retail are: (1) Location, (2) Location, and (3) Location.

That’s not quite true of basketball. Shot location is important to be sure, but how the shot was created, and how the defense affected it are large factors as well.

For instance, based on the 2011 MIT data, a shot from the free throw line, elbows or short corners is on average 10 percentage points less likely to go in than a jump shot from that same shooter near the rim. That is the affect location has on shooting.

Now factor in the defense. Given that contesting a shot drops it 12 percentage points, that means that, generally speaking, the open baseline jumper in C space is actually statistically better than shooting highly contested shots near the rim. So defense can trump location, if you want to look at it that way.

Now factor in shot creation. If a cutter can get near the rim and catch a pass, statistically speaking the catch and shoot shot inside is unaffected by the defense, making it perhaps the most ideal shot an offense can create. (And illustrating once again why the RGBs of offense: spacing, ball movement and player movement, are so important to winning basketball).

Basketballogy Shot Creation Model

I have put hundreds of hours of research into the taxonomy of shot creation, and that research has produced a few different shot creation models. The most simple of the shot creation models classifies all shots as one of the following six shot types:

[C] – Catch and Shoot – Cut
[S] – Catch and Shoot – Spot up
[D] – Dribble and Shoot
[K] – Keep and Shoot
[P] – Post up
[R] – Rebound Put Back

Note that a “keep and shoot” shot simply means that the player held on to the ball awhile before rising to shoot, perhaps watching cutters or pump faking their defender into the air. Also note that a “cut” doesn’t have to be a cut toward the basket. Cuts can be lateral, diagonal and even away from the basket. A Cut, Catch and Shoot shot is a shot where the player was moving to an open spot on the floor when the catch was made, rather than standing still waiting for a pass like a Spot Up, Catch and Shoot shot.

If you can discipline yourself to use these 6 shot types and 6 shot locations in your analysis, both on offense and on defense, you will open up to yourself a wonderful new understanding of any basketball game you are watching or playing in.

Every time you see someone take a shot in basketball, two letters should come to mind: how the shot was created (C, S, D, K, P or R), and the location of the shot (A, B, C, D, E, F, G or H).

Again, like learning to drive a car, this will be a bit awkward and unnatural at first, but it doesn’t take long to become an effortless skill, a skill that will bring you places you couldn’t otherwise go.

So let’s put your new found powers of game analysis to good use (and practice). Below is a 9 minute clip showing highlights of Michael Jordan’s 69 point game. For every one of Michael’s shots, I want you to mentally (or on paper) take note of the two letters.

For example, Michael’s first shot of the game is on a post up on the baseline in “D space,” so mentally note “PD” for that shot. Michael’s second shot was a “rebound put back” in A Space, so mentally note “RA” for that shot.

 

And here is a shot chart that isn’t lying to you.

Look over each of Michael Jordan’s makes on this shot chart, and note how the shot creation codes gives the chart so much more meaning.

mj69game

Again, I strongly encourage you coaches to acquire the habit of mentally noting the shot type and shot location each shot you watch, whether it be during a game, during a practice or on television.

As you train yourself to notice the shot creation and the shot location, you will begin to have new insights come to you. You will see each game’s flow and watch each team is “up to.” You will have a quick, intuitive understanding of exactly why teams are winning or losing, an understanding far beyond that of the casual (or even devout) basketball fan.

That little habit of seeing shot creation and shot location while watching (or playing) basketball will pay big dividends.

  1. todoinsttodoinst12-12-2012

    Tom, this is really a brilliant analysis. I think a big takeaway point for coaches is defense. Your article argues for pulling back the defense and forcing the offense to take F Zone shots and then moving quickly to contest those shots. Based on what you’re saying, this should have the effect of lowering the offensive shot percentage.

    What needs to be factored in, IMHO, is the effect on turnovers by not playing a more aggressive defense (M2M). Putting more pressure on the ball is likely to increase the turnover rate for the other team. At the same time, it increases the chances that the offense, when not turning the ball over, will penetrate for a better percentage shot. So that’s what I see as the trade-off.

    The other point I wanted to make is that the defense has to adapt this model to the individual offensive player. Particularly with kids in Middle School/High School, shooting percentages will vary dramatically. So, ideally, we want to identify the other team’s lower percentage shooters and “invite” them to take F Zone shots (and then contest the shot, of course).

    But I think your entire analysis opens up all kinds of creative thinking for both offensive and defensive strategies. Thank you.

    • Tom7Tom712-12-2012

      Three things.

      First, if I gave you my wife’s email address, would you write her and tell her how brilliant you think I am? [wink] Seriously, thank you for the kind words.

      Second, I am in the process of writing my defensive tactics out for inclusion in a book, and frankly I just couldn’t resist sneaking some of it into this article. On defense you have 1 goal: get the ball back without giving up points. The 2 most ideal tactics to achieve that goal are (a) create a turnover, or (b) get your opponent to shoot a poor quality shot. Shot location is one way to make a shot have poor quality, but think about this: forcing them to shoot off the dribble or a “keep” is another. If this concept is embraced, it will change a coach’s defensive strategies.

      Third, I LOVE your point about how backing off in the F zone may be surrendering opportunities to create turnovers, however… have you ever been frustrated by a player’s “dumb foul” in the F zone as well? The strategy you will want to take with the F zone may well depend on your players and the level you are coaching at, but…

      (and I guess this is #4), When you consider #2 (encourage shots off the dribble) and #3 (backing away from ball handlers in an F zone pocket), then you are effectively discouraging catch and shoots by discouraging passes out of the F zone, leaving keeps and dribble and shoot in F space for your opponent.

      That’s not a turnover, but those long rebounds can ignite a running game that has them fouling you instead of the reverse.

      Again, ALL of this is dependent on the level of play of your team and their opponents.

    • Tom7Tom712-12-2012

      By the way, you should join us at forums.basketballogy.com if you haven’t already. Not only would that help us bootstrap the forums, but you have insights others would appreciate.

Leave a Reply