5 Defensive Charting Insights From Missouri Tigers 74, Kansas Jayhawks 71

February 5, 2012 - by David Hess

For once the most-hyped game of the weekend lived up to its billing, as the Missouri Tigers and Kansas Jayhawks traded blows all evening. The game finished with Missouri scoring 11 consecutive points to snatch a 3-point victory away from Kansas.

The contrasting styles of the two squads meant that severe matchup problems seemed imminent. Missouri’s four-guard lineup was expected to draw KU’s shot-blocking big man, Jeff Withey, out of the paint and render him useless. And Kansas was projected to use their huge size advantage to score at will inside.

Because I was curious about quantifying how the matchup issues affected the game, I decided this would be an excellent candidate for a defensive charting session.

5 Biggest Takeaways From Charting The Game

The actual numbers are at the bottom of the post for those who are interested. But they’re worth nothing if they don’t lead to insights, so here’s the most important part — what I learned from reviewing the defensive tape, that I might have missed if I was watching as a casual fan.

1) Ricardo Ratliffe’s Foul Trouble Was A Blessing In Disguise For Missouri, At Least Defensively. Ratliffe played only 20 minutes against the Jayhawks, partly due to racking up 4 fouls. That’s 10 less than he has averaged in Big 12 games where he has committed 3 fouls or fewer. Those extra 10 minutes were mostly soaked up by Steve Moore, and he did a fantastic job defensively. Moore was Missouri’s top-rated defender, while Ratliffe was the worst by a huge margin. The difference in the second half is especially stark. In 10.5 second half minutes, Ratliffe allowed 17 points (mostly to Thomas Robinson). Moore, in 8 minutes, allowed only 2 points and forced 2.5 turnovers — and one of those was the biggest defensive play of the game, the charge drawn on Thomas Robinson with 1:43 left which wiped out 2 points that would have put Kansas back ahead by 7.

2) Kim English Did A Fantastic Job Guarding Jeff Withey. The 6’6″ English was responsible for neutralizing 7’0″ Jeff Withey when both were in the game, and he succeeded by throwing his weight around on the blocks. Withey struggled to get set near the basket, where he prefers to receive the ball, and as a result only attempted one shot all game. English rated as Missouri’s second-best defender, after Steve Moore.

3) Charges And Offensive Fouls Lost This Game For The Jayhawks. All the buzz immediately following the game centered on a dubious charging call against Thomas Robinson in the closing minutes, and another not-so-dubious charge committed by Tyshawn Taylor three possessions later. But those weren’t the only offensive fouls drawn by Missouri. This table breaks down both teams’ turnovers forced, according to what type they were.

Type of Turnover Forced	Kansas	Missouri
Live Ball Steal	7	4
Ball Out Of Bounds	3	5
Charge/Offensive Foul	0	5
Travel	3	1
Over And Back	1	0

The offensive fouls wiped out 3 made Jayhawk baskets, and cost them two more scoring chances. In a game decided by a single shot, that’s a huge amount of lost production.

4) Bill Self Should Have Played Jeff Withey More. Withey didn’t pull his weight on the offensive end, and he only recorded one official block, and that’s what most folks will remember about his game. But he did record two official steals, and his participation in double teams contributed to three other turnovers. He also forced several misses, while only getting beat for a basket once. He was essentially the only Jayhawk to emerge from this game with a good defensive rating. It’s tough to second guess Bill Self, but the end result was pretty stark — KU outscored Missouri by 12 with Withey on the court, and were outscored by 15 with him on the bench.

5) The Tigers Successfully Picked On Conner Teahan. Teahan had the highest defensive possession percentage on the Jayhawks last night, which means when he was on the court he was the player most likely to be involved in the play that ended Missouri’s possession. Unfortunately for Kansas, that’s because Missouri chose to attack Teahan, and were scoring on him consistently. The most visible instances were during the late comeback by the Tigers, as Marcus Denmon hit two threes with Teahan standing in front of him, flat-footed.

Defensive Box Score: Kansas Jayhawks at Missouri Tigers

Here are the numbers themselves, for those who are curious. Definitions are below.

A Quick Review Of Defensive Charting

Traditional player box scores have very little in the way of defensive record keeping, with only blocks and steals tallied. In order to get more detailed info, and to find out who actually does a good job of the main goal of defense — preventing the opponent from scoring points – it’s necessary to do the work yourself.

That means poring over game film (thank you for existing, ESPN3 and DVR technology) to chart the responsible defender(s) for any action by the offense that shows up in a box score.

For a thorough review of the process itself, you can check out this old defensive charting post. But the main idea is that every shot, turnover, rebound, and free throw by the offense gets credited to an individual defender (if possible). Then, we can use that data to construct a Defensive Rating that is analogous to the Offensive Rating that has recently become popular in basketball analysis.

Defensive Charting Definitions

These numbers come from four sources.

Taken from the traditional box score:

Min – Minutes played
DREB – Defensive REBounds

Tracked directly by the charter:

FM – Forced field goal Miss – when a defender forces an offensive player to miss a shot from the field. Oliver separates FM from Blocks, but we’ve lumped them together here.
FTO – Forced TurnOver – when a defender forces an offensive player to turn the ball over. Again, Oliver separates out Steals, but we’ve combined them. One thing to note here is that a player who draws an offensive foul is always credited with a FTO, even if it’s just a moving screen.
FFTA – Forced missed Free Throw Attempt – missed foul shots resulting from a defender’s foul
DFGM – allowed Defensive Field Goal Made – when a defender’s error or poor play leads to an offensive player scoring a field goal (intentional fouls at end of game excluded)
DFTM – allowed Free Throw Made – made free throws resulting from a defender’s foul (intentional fouls at end of game excluded)

Calculated Tallies:

Stops – the credit a defensive player gets for actions that contributed to ending an opponent possession. This isn’t as simple as adding FM + FTO + 0.4*FFTA, because the credit for a missed shot has to be shared with the defensive player who rebounds it. The formula is more complex than you might think, and includes a sliding weight for FM vs. DREB, based on how difficult those actions seem to be in each particular game. For full details, see Appendix 3 of Basketball On Paper.
ScPos – Scoring Possessions allowed by a player. This is essentially just DFGM plus a FT-related factor. Again, see Basketball On Paper for the full formula.
DPoss – [Stops + ScPos] – total Defensive Possessions that were credited to (or blamed on) a player.

Calculated Metrics:

Stop% – Stop Percentage — [Stops/DPoss] – the fraction of an individual player’s credited defensive possessions that ended with zero points. Essentially the inverse of offensive Floor%.
%DPoss – Defensive Possession Percentage — [(Min/40)*DPoss/TeamDefensivePossessions] (for a non-OT game) – the percentage of team defensive possessions faced by an individual defender. Analogous to %Poss on offense.
DRtg — Defensive Rating – [(1–%DPoss)*TeamDRtg + %DPoss*(100*TeamDefPtsPerScPoss*(1-Stop%))] – individual Defensive Rating. Gives a player credit for stops and scoring possessions he was directly involved in, then assumes a nebulous team-average performance in the other possessions. This is the analog of offensive rating.

Chart A Game Yourself! Other People Are Doing It.

We’re working to develop a new section of the site that highlights all the defensive charting efforts in the stat community, and we’d love for anybody interested in charting to shoot us an email. We’ll provide an Excel template and some tips to get you started, and you are welcome to publish the results on your own blog or in a guest post here at TeamRankings.