Tuesday, March 2, 2010

Examining the slump -- offense or defense?

One of the first things I do when dissecting why a team is winning or losing is simply to check whether the offense or defense is more to blame. People inherently focus on scoring -- there will be a game where the team loses 97-95 and their fans will scream about a turnover or missed shot, all the while ignoring the sieve that was the defense.

So what about the Hoyas? The team is slumping badly with its most recent loss to a good WVU squad on the road (which, as Brian points out, was mostly caused by offensive turnovers and a distinct lack of defensive turnovers).

One simple way to look at a team is to look at offensive and defensive efficiencies. As of the WVU game, Georgetown has an adjusted offensive efficiency of 114.5, good for 20th in the country.

What does this mean? That Georgetown could be expected to score 114.5 points in 100 possessions against an average D-I team. Georgetown's defensive efficiency is 92.4 (43rd), which means it could expect to give up 92.4 points versus that same average team.

In short, the offense has been better than the defense right now.

But that hasn't always been the case.

I went game by game and took Georgetown's offensive and defensive efficiency in each game, adjusted for home/away games and the opponent's current efficiency for the season, to see how well Georgetown's offense and defense performed over the course of the season.

To put this in the context of a typical Georgetown game, I converted those efficiency numbers into points, based on a 67-possession game.

In short, the numbers below are the number of points per game that Georgetown played above or below an average NCAA in each game. The average NCAA team is someone like Loyola Marymount, Lipscomb or Indiana this year; so being average here is not a good thing, and decidedly worse that being an average team in the Big East.

How is this different than what Brian did here?

Well, Brian was looking at how Georgetown performed relative to its own expectation;. I'm trying to evaluate Georgetown's performance against a standard baseline (i.e. the average NCAA team) to see, overall, how the offense and defense have performed, given the competition.  It's really just an offset between the two analyses.
.                 (Above Avg. Team)  (Below Avg Team)
Games               Points Scored     Points Allowed
First 7 Games             7.8               9.2
Second 7 Games            6.3               8.2
Third 7 Games            12.1               4.8
Fourth 7 Games            8.7               4.2

In the first seven games, the Hoyas had some creampuffs, the Temple offensive debacle and a rather balanced performance versus Butler.

Starting with the Butler game and running through much of the second 7 games (including Washington), the defense carried Georgetown for the most part. In the Old Dominion game, the offense was actually below NCAA-average.

Starting with Seton Hall, the team started to get hot on offense, but also a bit schizophrenic. In four of the seven games in this quartile, the Hoyas posted offenses 18+ points above NCAA Average in a 67-possession game. Yes, NCAA-average isn't very good, but 18 points differential due to the offense in a regular Georgetown game is pretty darn good.

The defense started to decline, though, and in the South Florida game, neither the offense nor defense was any good.

By the last set of games, the offense had come back to earth but the defense hadn't revived.

Looking at the losses:
Game              Offense        Defense
ODU                 -1              5
South Florida       -1             -4
at Rutgers           8             -5
Notre Dame           3            -11

at Marquette         9              7
at Villanova         5             11
at Syracuse          0              7
Syracuse             6              6
West Virginia        6              5

I divided them up into perceived "bad" losses and "acceptable" losses. It's worth noting that versus Marquette and Nova, Georgetown played better than in some of their wins. The Syracuse games were pretty bad; at home the Hoyas played better than versus Temple but that's about it.  Overall, the defense plays as well or better than the offense in losses against marquee opponents.

In the three "bad" in-conference losses, the defense has been more to blame. But aside from the Rutgers game, the offense wasn't exactly pulling its weight, either. Still, 11 points worse than an average D-I (read: Indiana) defense versus Notre Dame? Ughh.  Overall, the defense plays terribly in losses against "easier" opponents.

Here's the whole season, along with the season to date running average after the seventh game -- you can see how the defense has slowly declined:
Game                   Offense  Defense  Total  O Avg  D Avg
Tulane                   12         5      17   
Temple                  - 9        19      10   
Savannah St.              6        10      16   
Lafayette                23         1      24   
Mount St. Mary's         10         6      16   
American                  2        13      16     7.5    8.9 
Butler                    9        11      20     7.8    9.2 
Washington                1        19      20     6.9   10.4 
Old Dominion            - 1         5       4     6.1    9.7 
Harvard                   6         9      15     6.1    9.7 
St. John's                9         3      12     6.3    9.1 
DePaul                   15        10      25     7.0    9.1 
Marquette                 9         7      15     7.2    8.9 
Connecticut               6         6      11     7.1    8.7 
Seton Hall               18         0      18     7.8    8.1 
Villanova                 5        11      17     7.6    8.3 
Pittsburgh               21         5      27     8.4    8.2 
Rutgers                  20         3      23     9.0    7.9 
Syracuse                - 0         7       7     8.5    7.9 
Duke                     22        10      32     9.2    8.0 
South Florida           - 1       - 4     - 4     8.7    7.4 
Villanova                16         7      23     9.1    7.4 
Providence                7        13      20     9.0    7.6 
Rutgers                   8       - 5       3     9.0    7.1 
Syracuse                  6         6      12     8.8    7.0 
Louisville               15        14      29     9.1    7.3 
Notre Dame                3       -11     - 8     8.8    6.6 
West Virginia             6         5      11     8.7    6.6

Notice that the offense got better as the season has progressed before stabilizing in February, while the defense has been steadily trending downward since the Washington game.

1 comment:

  1. Good half/bad half:
    Bad 2nd half defense was the biggest factor in the upset losses to USF, Rutgers, and Notre Dame.
    Bad 1st half defense got the team too far behind at Villanova, at Syracuse, and at WVU.
    Those 6 losses had 7 of the 9 halves all season with DE above 120.
    The ND 1st half also was bad, but not as bad as the 2nd half. Against Seton Hall and Villanova at home, the 2nd half defense was bad but not enough to lose the 1st half leads.