Saturday, March 26, 2011

Keys to Winning....Defense

As part of my review of the Falcon basketball season, I wanted to look at some of the tempo-free stats and whether they led to a tendency to win or lose.

A couple things here.  First, there are two key elements.  First, is the record, but second is how far away from the mean do you have to get before you see something extreme with records.  If it is close to the mean, they that's pretty important...it means your team is having trouble in relatively common circumstances.  If it is far from the mean, they it is an outlier and something you would expect to have a big impact on your record.

For example, I wrote a lot about how BG had not won a game when it allowed 1.02 points per possession or more.  BG finished the season at 1.0 points per possession and the national median was 1.01.  The fact that BG was unable to win when they allowed even a little bit over their average means that the team's offense provided no margin for error.  If BG did not get stops, their offense simply did not bail them out.

BG was 0-12 when allowing over 1.02 PPP.  You had to get down to .9 PPP before you start to see some semblance of being sure you would win, at 5-2.

We will return to this theme.

Now, points per possession is made up of a bunch of different things.  One of them is getting teams to miss shots.  In fact, studies have shown that this is true--and it seems obvious that it would be.  We use the Effective FG%, which counts 3-FG as 1.5 when doing the math, to reward teams for taking the risk of shooting a 3.

BG allowed 50.8% as an average.  Nationally, the media was 48.8%, so the Falcons were slightly below average on this measure, probably due to weak 3-defense .  When BG allowed EFG% of 54% or above, they were 1-10 on the season.  I'm not sure this is quite as surprising...certainly we needed to defend the shot better well to have a shot at winning, but I don't know how many teams win giving up over 54%.  Perhaps the more alarming stat is that it happened 11 times.

As opposed to the mirror image on the plus side....BG held teams under 46% only 7 times, and lost 3 of those games.

Now, when you get a team to miss, you have to get the rebound to end the possession.  Any Falcon fan would be able to tell you that the team struggled mightily in some games in protecting the offensive boards.  For the season, BG was at 33% which is the neighborhood of the typical national average.  However, go up to 35% allowed, which isn't very far, and the team is 2-11.  So, you have a team that struggled a little getting misses, and then a team that doesn't get the misses that do occur, and you're going to have a a hard time winning those games.

On the plus side you have to go down to 28% to see an impact, and even then, BG was only 7-3.

The other scoring factor is free throws.  I believe this was a serious part of our offensive issues, but on defense, BG again was right on the national average.  Using the FT formula (FTA/FGA), we see that BG allowed a rate of 38, which means for every 100 FG attempts we allowed 38 FT attempts.  The national average is 37.6.

On defense this simply doesn't appear to be much of a factor.  If you go all the way up to a FT Rate of 57, BG is 1-6, but you'd expect that, and when BG's opponents were below 20, the Falcons were 6-2, and I suspect you'd find that most times, too.

There is one thing you can do, of course, when faced with these shooting and rebounding issues...stop a shot from happening at all by getting turnovers.  For the part of the season where BG was thriving, this seemed to be the key element.  Nationally, 1 in 5 possessions ends in a turnover.  BG created turnovers on 23% of its defensive possessions.  This clearly impacted winning.  At just 24%, BG was 8-3.  

The key conclusion, to me, is that BG did not have the horsepower to stay with people who were shooting well.  We had to defend the thought.  Also, though, if you look at the results above, you can see that there were a few occasions when BG wasted a victory-caliber defensive performance, but very rare that offense bailed the defense out.  (If ever).

I would argue the following quality defensive performances were wasted...

Niagara (.96 points per possession)
@Detroit (.93)
@Akron (.93)
@Howard (.84)
WKU (.83)

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