NCAA DI Rankings 10/24/2016

What is the difference between a “poll” and a “ranking” when applied to sports teams? A poll, sometimes known as a rating, involves an opinion of the team’s performances by several people who are knowledgeable about both the sport involved and the teams in question. Hence a poll is a vote and a subsequent ordering of teams based upon this vote. A ranking usually involves a mathematical calculation based on the performances of the teams in question and the performances of their opponents. Therefore, a ranking is a statistical concept which evaluates the performances of teams. In general, polls and rankings complement each other because each represents a different viewpoint and a different “skill set” in terms of evaluating volleyball.

The Net Set Ranking is a numerical average based upon the performances of teams in four other polls or rankings. In the Net Set Ranking, the team’s position in each of the four polls is summed and then averaged to create a Rank Index. This Rank Index is then arranged, or ranked, in ascending order, with the lowest Rank Index determining the number 1 team in the Net Set Ranking, and so forth.

Net Set Rankings and the Rank Index are an average from these four polls or rankings.

1. The AVCA Coaches Poll (https://www.avca.org/polls/di-women/index.html).

AVCA, or the American Volleyball Coaches Association, publishes an outstanding weekly poll for each volleyball division from its member coaches in that division. Thus, DI coaches are voting on the teams in the DI poll.

2. The Rich Kern Poll (http://www.richkern.com/vb/FreePage.asp).

Richkern.com has a free portion and a much larger premium service. The premium service is well worth the modest subscription fee of $25.00 annually. This poll has been around for a long time and the pollsters are journalists and volleyball fans who really know their stuff. To see the Rich Kern Poll intact, or lots of other neat volleyball stuff, go to: (http://www.richkern.com/vb/rankings/FreePageRankings.asp).

3. The Pablo Rankings (http://www.richkern.com/vb/FreePage.asp).

The Pablo Rankings are an incredibly ingenious ranking system that operates on a probabilistic, algorithmic approach and analyzes and measures the difference in abilities between two teams overall and in a match. In terms of accuracy and predictive analytics, the Pablo Rankings are the most accurate mathematical model available today. You can find a detailed explanation of the Pablo Rankings at this web location. http://www.richkern.com/vb/rankings/PabloFAQ.asp . View the Pablo Rankings, the best pure statistical ranking available, at RichKern.com:(http://www.richkern.com/vb/rankings/FreePageRankings.asp).

4. The NCAA RPI Index (http://www.ncaa.com/rankings/volleyball-women/d1/).

I am not a proponent of the RPI, but since the RPI ranking is one of the main discriminators for determining the at-large bids to the National Championship Tournament, it should be described. Here is the basic formula for the RPI rankings currently used by the NCAA. Please note that several variations of this formula exist, but the one below is the basic formula.

RPI = (Winning%*.25)+(Opponent’s Winning%*.50)+(Opponent’s Opponents Winning% *.25)

(The Winning% is calculated by dividing team’s wins by the number of games played.)

As you can see from the formula above, 75% of the rating comes from how a team’s opponents performed (aka Strength of Schedule) while only 25% of the rating is based on the team’s actual performance. Quite frankly, that just isn’t statistically correct. Nonetheless, it is used by the NCAA for seeding and at-large bids. To see the all NCAA Division I RPI Index rankings, go to this web location:

(http://www.ncaa.com/rankings/volleyball-women/d1/ncaa-womens-volleyball-rpi).

Now, on to the Net Set Ranking for 10/24/2016, which, once again show some major changes in DI women’s college volleyball.

LET’S GROW VOLLEYBALL!