Down the road, we hope this site expands into something much larger, like previews and recaps of matches, tournaments and the postseason. This site is still in it’s infancy, so those ideas are down the road when, hopefully, some funding can help expand our project..
Until then, IPV posts up-to-date ratings based on all of the scores received from the 400+ Indiana high school volleyball programs. Using those statistics, IPV has unveiled their own ratings system (Z-Rating) that we hope will be a more accurate snapshot of how the teams rate based on previous results. It’s not perfect yet, but we’ll be adding minor tweaks that we think will help make it the most accurate ratings system for volleyball on the market.
Z-Rating is the volleyball-centric rating system that IndianaPrepVolleyball.com has put together to try and rate every team in Indiana high school volleyball in a accurate fashion (or as accurate as we possible can).
The main purpose of the Z-Rating is to show where a team’s results thus far have placed them among the rest of the state. It does not predict where a team will be at the end of the season–only what you’ve done so far. Z-Rating also has a predictive tool that can also be used to predict the average point margin between two teams in a set based solely on previous results.
Ex: if Team A’s Z-Rating is 24.50 and Team B’s Z-Rating is 20.50, then Team A would be predicted to win a set by four points on average. Z-Rating takes into match wins and losses as well as set wins and losses. Ex: A 3-0 victory in a best-3-of-5 format would weigh heavier on a team’s rating than a 2-0 victory over the same team in a best-2-of-3 format. Moreover, a 3-1 win (best-3-of-5) over an opponent would hold more weight towards your rating than the weight a 2-1 (best-2-of-3) rematch victory would hold for the opponent if they beat you. The top-rated team in our Z-Rating–among all classes–has a 25.00 rating. We’re very proud of our ratings system that took us over two years to be confident enough to unveil. We think you’ll find it far more accurate a ratings system then others, like the RPI.
The Rating Percentage Index, commonly known as the RPI, is a quantity used to rank sports teams based upon a team’s wins and losses and its strength of schedule. It is one of the systems by which NCAA basketball, baseball, hockey, soccer, lacrosse, and volleyball teams are ranked. This system has been in use in college basketball since 1981 to aid in the selecting and seeding of teams appearing in the 68-team men’s playoffs, and for the 64-team women’s tournament since its inception in 1982.
In its current formulation, the index comprises a team’s winning percentage (25%), its opponents’ winning percentage (50%), and the winning percentage of those opponents’ opponents (25%). The opponents’ winning percentage and the winning percentage of those opponents’ opponents both comprise the strength of schedule (SOS). Thus, the SOS accounts for 75% of the RPI calculation and is 2/3 its opponents’ winning percentage and 1/3 its opponents’ opponents’ winning percentage.
We pull records from MaxPreps.com (IHSAA has entered into agreement with them for score entry), but not everyone fills in all the blanks for us there. So, we try to find results elsewhere, but we’re bound to miss. There are three ways to help us keep your record up-to-date: 1. Keep your team’s MaxPreps scores up-to-date. To find your team’s page, look for it in the directory here (you may have to sign up for a free MaxPreps account to update scores). 2. Send your scores to us via twitter.
Our account name is @IndianaPrepVB. Please include as much information as you can regarding the match (date, scores of each set, etc.). Only one match per tweet, please. Matches without the sets won for each team cannot be entered into the system as they are vital to the accuracy of the ratings. 3. Send your updated win-loss results to scores[@]indianaprepvolleyball.com. Please include as much information as you can regarding the match (date, scores of each set, etc.). Matches without the sets won for each team cannot be entered into the system as they are vital to the accuracy of the ratings. If you send us any results, we’ll look to include them in our next update.