I acquired all of the Division I team data since 2002, and from that we can observe some fascinating trends and data relationships in the data. This is a multipart series exploring some of that data.

Now we'll move onto other facets of Defense, and start with Percentage Loss of Ball Forced(%lob). The number is computed by dividing the number of possessions by an opponent by the number of the opponent's turnovers. This analysis uses the "Smith Method" of defining a possession which is defined as ending whenever a team loses control of the ball. A possession can end with a made basket, a trip to the free throw line (1-and-1, 2, and 3-shot situations), a turnover, or an attempted field goal. It is important to remember the latter when gaining an understanding of this data compared to data published elsewhere. Stay tuned for much more on the topic of Possessions when I address the Ken Pomeroy data.



The graph shows the Percentage Loss of Ball, by year, for the last 23 seasons. The grey line shows the Percentage Loss of Ball for all of Division I, while the green line shows the %lob for teams that made the NCAA tournament that year. Over time there has been a noticeable decline in %lob by opponents, like we saw with the offensive side of things.

What has not changed is the tight difference between tournament teams and the national average.

UNC, shown in blue, followed the national and tournament averages up through its most recent National Championship, but has fallen below those benchmarks since. The Hubert Davis/RJ Davis era so far has seen an extreme decline in Loss of Ball Forced.

Percent Loss of Ball Forced has a correlation factor with Winning Percentage of +0.186, which shows that it is a very worthless stat, unlike its offensive counterpart, interestingly.

Next up: Percentage Loss of Ball Forced vs. Points Per Possession Allowed

I couldn't watch that show with kay and the media kissing his cheating a## but apparently our guy RW said this ---->
My $$$ is on Jamie Luckie. Who do you guys think it was?
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Coach K & Roy Williams Rivals Reunited, a one-hour special featuring coaching legends Mike Krzyzewski and Roy Williams sitting down together for an extensive conversation for the first time since their college coaching careers began over 40 years ago, debuts Wednesday, Feb. 28 at 9 p.m. on ACC Network. The conversation is hosted by Wes Durham. (GoHeels.com)

Drake Powell #10
Ian Jackson #19
Elliot Cadeau #35

Anybody watch this? Great stuff! I love this part about Roy actually admitting he would purposely not call a time out just to piss people off:

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Can anyone recommend the Kimpton Monaco Hotel @ Capital One Arena?

I acquired all of the Division I team data since 2002, and from that we can observe some fascinating trends and data relationships in the data. This is a multipart series exploring some of that data.

Finishing up with defensive shooting stats, we'll tackle Effective Field Goal Percentage Allowed (efg%). To review, this stat weighs 3-point shooting so that the value of the shot is considered in the percentage. The calculation for this stat is:

efg% = (fgm + (0.5 * 3fgm)) / fga

Click to expand...

Both fgms and fgas include 3-pointers, but we add in 50% more for the 3fgms since that is how they are scored. The problem with this equation is that it is possible to get a result higher than 100%, but nevertheless, it still is more popular than overall field goal percentage in measuring a team's potency from shooting.



The graph shows the national average in grey, the average for NCAA Tournament teams in green, and UNC's average in blue.

From this we see that national eFG% has essentially hovered in the 49% range for the past 23 seasons, with a slight elevation in 2016. The standard deviation is 2.7 percentage points, so we see a wide variation among college basketball in this defensive stat.

Tournament teams demonstrated the same pattern as the national average, unlike with the eFG stat covered in Part 5. It appears, though, that tournament teams' opponents generally shoot 2.0 percentage points worse than the national average.

UNC's efg% history has followed the tournament average well until its last National Championship. Since then the program has lived between the national and tournament averages, a trait we haven rarely seen. The current team, however, appears to be exceeding the tournament by around 2 percentage points. That's only been seen with the 2012 and 2015 teams.

How useful is Effective Field Goal Percentage? It correlates with Winning Percentage more than most stats. On a scale of 0.0 to 1.0, it has a -0.627 correlation factor. Unlike its offensive counterpart, Effective Field Goal Percentage Allowed has a higher correlation factor than total field goal percentage. Therefore, this is an excellent stat to follow.

Next up: Percentage Loss of Ball Forced