Tuesday, December 29, 2009

Looking back in anger

As the Big East regular season gets under way, it comes time to wonder what we've learned about the Hoyas so far this year.

About this time last season I also wondered what November and December had demonstrated - heading into a home game against Pittsburgh, Georgetown was ranked #1 overall by Ken Pomeroy, with a net adjusted efficiency (adj. off. eff. - adj. def. eff) of + 42. That is, we expected that the Hoyas would outscore the median Div-I team (e.g. Holy Cross or Hofstra in 2009) by 42 points in 100 possessions.

I was so excited that I made one of those fancy-pants graphs to demonstrate visually just how good Georgetown was (click any figure to enlarge):

2008-09 Big East Aerial (31-Dec-08)
You'll need to read this post to understand everything in this figure, but simply:  upper-right = good; lower-left = bad.

The Hoyas went 6-14 the rest of the way.  Obviously, that figure - and the Hoyas early season performance - didn't tell us what was to come, only what had happened so far.

Now I could simply knock out this year's version and let it rest, or I could stare at a bunch of numbers on a spreadsheet and try to understand why the early season performance by the Hoyas was such a poor predictor of the rest of the season.

Let's do both.

First, here's this year's aerial, through games played Monday:

2009-10 Big East Aerial (28-Dec-09)

As conference play gets underway, Syracuse and West Virginia appear to be the class of the Big East, both with fairly balanced teams (offense vs. defense efficiencies).

Georgetown, surprisingly, is a solid third by KenPom's ratings, although the team is highly dependent upon its defense (#1 in the conference) as the offense is merely average.

Following is an enormous cluster of teams, headed by Marquette and Villanova and followed by St. John's, Pitt, UConn, Louisville, Seton Hall, Cincinnati and South Florida.  That's nine teams all grouped together.

Notre Dame - which almost fell off the chart with its extreme of the league's best offense and worst defense - and Providence are slightly behind the peloton, and Rutgers and DePaul hold the final two spots.

A few points to make:
  • Note that the scaling on this year's aerial is slightly different than last year's.  The offensive scale doesn't go quite so high and the defensive scale doesn't go quite so low.  For instance, Notre Dame had better adj. off. and def. eff. stats last year, while this plot may lead you to think that their offense is actually better this year.
  • The elite teams this year aren't quite as elite as those from last season headed into January.  Since four Big East teams made it to the Elite 8 last year, a drop-off this time isn't unexpected.
  • No team last season made it to the NCAA tournament from behind the isopleth that crosses the solid diagonal at OE=107, DE=93.  This year, S. Florida sits just behind that line.  Three teams that were ahead of that line last year (Georgetown, Notre Dame and Cinci) failed to make the tourney, although they were bubblicious until the end.  If that's any sort of bellwether, it would mean 12 Big East teams are capable of making the NCAAs this year (although obviously some will not).
  • A few teams may look out of place:
    • Georgetown's pedestrian offense may seem unusual, but did you know that the Hoyas have finished higher than 8th in off. efficiency in the Big East only two times in JTIII's first five seasons (2006 & 2007)?
    • Louisville's offense is better than their defense?  The Cardinals have finished 4th, 2nd, 1st and 1st in def. efficiency in conference their first four seasons.  If the offense can tread water, expect Louisville to improve as its defense does.
    • Pitt was one of the most lopsided teams last year - they had a great offense and mediocre defense.  It's the opposite so far this year.
    • To my eye, the most dramatic year-over-year improvement is S. Florida, but I'm not sure how they'll do without Gus Gilchrist for the foreseeable future.  St. John's is also far ahead of last year.

Okay, that was fun, but what about the real issue - how well can we predict the rest of the season from how well a team plays in November and December?

Here's Georgetown's won-loss record for the past 6 seasons in the early part (all games in Nov. and Dec.) and late part (Jan. - Apr. games) of the schedule:
.                Early                  Late
Season       W   L     Net         W   L     Net 
2003-04      9   0   + 28.8        4  15   - 11.8
2004-05      8   3   + 13.7       11  10   +  1.1
2005-06      8   2   + 21.2       15   8   +  7.7
2006-07     10   3   + 23.1       20   4   + 15.7
2007-08     10   1   + 31.9       18   5   + 12.1
2008-09     10   1   + 29.6        6  14   -  3.6
That third column for each segment ("Net") refers to the difference between off. and def. efficiency during those games.  It turns out that the best two W/L records, and the 2nd and 3rd best net efficiencies from early season preceded two epic collapses - yes, this dataset goes back to the final Esherick season, although this is just a coincidence since this is as far back as KenPom's database goes back in time.

Now hopefully, if you're my regular reader or you've bothered to make it this far down the article, you'll want to dig a bit deeper into those numbers above.  For instance, what was the quality of competition like during each early season?  If we adjust the underlying off. and def. efficiencies for that competition, what would the net eff. numbers look like?

Let me tackle those one at a time.  First, I'll re-post those net. eff. numbers with the opponents' average KenPom rating:
.             Early                    Late
Season      Net   Rating             Net  Rating
2003-04   + 28.8   258             - 11.8   63
2004-05   + 13.7   175             +  1.1   55
2005-06   + 21.2   190             +  7.7   49
2006-07   + 23.1   150             + 15.7   48
2007-08   + 31.9   160             + 12.1   59
2008-09   + 29.6   119             -  3.6   61
Clearly, JTIII does not subscribe to Esherick's (and by proxy, his father's) scheduling philosophy.  The 03-04 team was simply getting fat on a bunch of low-major teams early season, and never had its mettle tested until conference play got rolling.  The 08-09 bunch, however, played the toughest early-season schedule so far - remember that the UConn game last year was played before New Year's, so it is included.  The huge drop in net efficiency last year came after the team looked to be able to handle just about anyone early on.

Let's now take a look at each of the individual efficiencies, now adjusted for competition during the segment.  This is analogous to looking at KenPom's Adj. Efficiencies, rather than raw efficiencies.  As I mentioned at the top, when we discuss adj. efficiencies, what we mean is how would we expect the team to perform against an average Div-I team.

Here we go, looking at offense first:
.                Off. Eff.
Season     Early  Late   Diff.
2003-04    103.9   96.2  -7.7
2004-05    106.9  113.2   6.3
2005-06    109.9  117.7   7.7
2006-07    113.8  125.9  12.1
2007-08    119.1  114.3  -4.8
2008-09    117.4  108.3  -9.1
The last Esherick team was the worst offensive team in the group, both early and late season, once you adjust the stats for the level of competition.

One of the great mythical concepts of the Georgetown/Princeton offense is that it is massively complex and takes considerable practice time and game experience to master.  The first three seasons under JTIII certainly give evidence to that, as the team improved from early season to late season.  This wasn't the case in 07-08, where the team was stocked with upperclassmen and operated at a high level even with the step back in conference.  But last year's team showed the biggest overall drop intra-season, and the roster had only 1 junior and 1 senior - surely an improvement should have come.

It's also worth noting that, in spite of the collapse last year, the team was still scoring more than 12 points per 100 possessions more than the 03-04 club.

.                Def. Eff.
Season     Early  Late   Diff.
2003-04     91.6   92.8   -1.2
2004-05     97.3   94.4    2.9
2005-06     92.9   92.6    0.3
2006-07     89.1   88.7    0.3
2007-08     87.2   85.3    1.9
2008-09     82.6   95.0  -12.4
Excluding last season, this table just makes a lot more sense to me.  I can understand offenses going to slumps, for example due to a prolonged stretch of poor outside shooting, but I'd expect that a team's defensive ability will be fairly well established in the first two months of the season, once the level of competition is accounted for.

An important trend, and one that I don't think most fans or analysts are picking up on, is that each Hoya team in the JTIII era has been better defensively than the previous year's team, and had improved from early-season to late-season.  Heading into Jan. 2009, Coach Thompson was beginning to look like some sort of defensive genius.

Then the wheels came off.

If we use the Esherick team as an archetype for one that had lost its confidence, or perhaps better a coach that had lost his team, we still see only a small drop in the quality of defensive play.  Last season, there were no significant injuries yet the defense on the court in conference play not only didn't resemble the early season team, it broke with a general trend over a five-year period.

.                Net Eff.
Season     Early  Late   Diff.
2003-04     12.3    3.4   -8.9
2004-05      9.6   18.8    9.2
2005-06     17.1   25.1    8.0
2006-07     24.8   37.2   12.4
2007-08     31.9   29.0   -2.8
2008-09     34.8   13.3  -21.4
Finally (for tonight), I'll summarize the previous tables with the net adj. efficiencies for the past six seasons.  I think its worth noting that, as much as we like to decry the late season swoon last year, it's worth recognizing that the early season performance was about as good as the Hoyas have played since JTIII arrived, just a touch below the 06-07 team during its run to the Final Four.  The shock wasn't so much how poorly they were playing by the end of the season, but rather how far they had fallen in such a short period of time.

While the Esherick team's collapse wasn't nearly as large, that team simply wasn't good enough to start with to be able to collapse very far.

Tomorrow, I'll dig a bit deeper into the underlying stats, and take a look at what we've learned so far this year.

1 comment:

  1. HoyaChris Here:
    I continue to insist that you have more than one reader and I can't tell you how thrilled I am to see the use of "isopleth" in a basketball article.

    I think tonights game will tell us a lot. I can't imagine us being taken by surprise, and almost all of our minutes will be going to players who were an integral part of last seasons late debacle. Understanding that leadership is an oft-overated term, I believe that Greg's play tonight will be the best leading indicator of our season's likely outcome.