Tues. 2/23/10
The Math Behind The Rankings
We here at USHR have been receiving a lot of questions about how the new playoff system works. Instead of replying to multiple emails with the same information we will do our best to explain the mathematics the formula is built on, and hopefully address many of the questions that have been sent to us.
In order to understand the system one must first start with the calculations for RPI. RPI, which stands for Ratings Percentage Index, is set up as a way to rank all of the NEPSIHA teams in an equitable manner, taking into account both results and strength of schedule. The RPI is split into three categories. The first is winning percentage, which is self-explanatory. This is worth 25% of the final RPI calculation. The second category measures your opponents' winning percentage. In other words, how good are the teams that you are playing? This category is worth 21% of the RPI calculation, which you will note recognizes that how you play -- your own winning percentage - is of greater weight than how your opponents play, i.e the second category. The third category is opponents' opponents' winning percentage and is worth 54% of the RPI calculation. This category is truly a strength of schedule component and it was created to reduce the variation that happens for some teams on a yearly basis. It also eliminates any benefit that might come from running up gaudy won-loss records vs. weak teams.
Once the RPI numbers are calculated, the top 16 teams (based on the RPI) are then put into what is known as the JSPR system, which ultimately determines the seedings for what we have been calling the ‘big tournament', i.e the elite 8. The JSPR system offers a deeper comparison of the relative strengths of the Top 16 RPI Teams - aka "Teams Under Consideration." It does so based on four criteria that we will get to shortly.
We should first mention that teams under consideration have been limited to 16 teams because it was determined that 16 teams provides a large enough sampling to determine the top eight teams overall. It would be extremely time consuming and of dubious benefit to evaluate all NEPSHIA teams under the JSPR system because of the fact that if a team doesn't make the top 16 in RPI, there is virtually no chance that they would crack the top eight in the JSPR system - they simply would not have won enough games against the top teams. Teams within the top 16 in RPI have a legitimate chance of cracking the top eight of the JSPR system and making it to the big tournament.
OK, how does the JSPR system work? What is does is take the top 16 teams in the RPI, and then, using four separate categories, compares each of those teams to the other fifteen teams. In many cases, there are head-to-head results, but let's say that we wanted to do a virtual comparison of Kent and Nobles. These two teams have not and will not meet in the regular season so there is no way to say one team is better than the other based on head-to-head play. What the JSPR system does is utilize statistical data to determine which team would come out on top in this hypothetical matchup. It would be great to set up a computer simulation, knowing the strengths and weaknesses of every player on each team, but since that is not possible, we can only look at the numbers that we have access to. The four categories the JSPR system uses in order to compare two teams are as follows.
1. Head- to-head result (if the teams have actually played on the ice the team who won should get credit for that).
2. Comparing the two teams RPI (how do the two teams stand against all other NEPSHIA teams)
3. Record against mutual opponents (if the two teams have played the same teams on the ice the results against those teams gives us a good indicator about the teams being compared)
4. Record against teams under consideration (how have the two teams played against the top sixteen teams in NEPSHIA)
After the two teams under consideration are compared in these four categories, a virtual winner is declared. For purposes of illustration, let's go back to our example of Nobles and Kent, our two top RPI teams.
Since Nobles and Kent have not faced each other, that first category gets thrown out - no winner there. In the second category, Nobles has a higher RPI, so they pick up a point there. In the third category, Kent has a better record vs. mutual opponents, so they earn a point. In the fourth category, Kent has a better record against the top 16 RPI teams - aka ‘Teams Under Consideration' - and picks up a point there as well. So, the finally tally is, Kent 2, Nobles 1. And Kent is declared the winner of the hypothetical matchup.
We should point out that, because there is an even number of categories being compared, there is always the chance that two teams will be tied in our simulation. If that is the case, the first tiebreaker is head-to-head play (the best indicator of comparative strength of these teams), the second is RPI (the most all-encompassing category), the third is record against mutual opponents, and the fourth is record against teams under consideration. In the end the ‘winner' of the virtual comparison, Kent, is placed into a table similar to the one shown below.
This entire process is repeated for each possible matchup, of which there are 120, and each team is involved in 15 of them. The total number of ‘wins' is then added and the team with the most ‘matchup points' garners top seed in the tournament. Second highest amount of points gets the second seed, and so on. Should teams get equal amounts of points in the final table, the winner of their JSPR comparison gets the higher seed.
In summation, the RPI portion of the system takes the results on the ice, and finds the teams that get the best results out of the most difficult schedule. From there, the best teams are compared to each other through the JSPR which rewards teams for winning games on the ice against the best teams in New England. So, in the end, the teams that win the most games against the iron of prep hockey will be the top seeds.
We should point out that when USHR publishes the current RPI or playoff standings they are for that week only. In other words, the teams in the top 16 based on RPI can change each time a new set of games is played. Also, when teams in the top 16 play each other it can change their comparisons and consequently their JSPR ranking. It's all very fluid. Naturally, the greater number of games remaining to be played the greater the potential volatility in the rankings. Just as in the past, the best teams will go through to the playoffs, and, with three tournaments now, more teams will be playing playoff hockey.
The JSPR system is not utilized for the second and third tournaments, the so called ‘large school' and ‘small school' tournaments. The seedings of those are determined strictly by RPI. In other words, once the elite 8, which is open to both large and small schools, is determined, those eight teams are taken off the RPI list. From this shortened list, the eight highest-ranked large schools are placed in one tournament, and the eight highest-ranked small schools are placed in the other.
Sun. 2/21/10
This Week's Schedule
Mon. Feb. 22
Cushing @ Lawrence, 4:15 pm (rescheduled from 2/10)
St. George's @ BB&N, 4:30 pm (rescheduled from 2/10)
Gunnery @ Millbrook, 4:30 pm
Holderness @ New Hampton, 4:30 pm
Thayer @ Governor's, 5:00 pm (rescheduled from 2/10)
Noble & Greenough @ Groton, 5:00 pm (rescheduled from 2/10)
Brewster Academy @ Andover, 5:00 pm
Wed. Feb. 24
Westminster @ Andover, 3:00 pm
Middlesex @ BB&N, 3:00 pm
Thayer @ Groton, 3:00 pm
Greenwich @ Kingswood-Oxford, 3:00 pm
Brooks @ St. Mark's, 3:00 pm
Newton Country Day @ EIL Tournament, time TBA
Tabor @ Cushing, 3:15 pm
Exeter @ Winchendon, 4:00 pm
Northfield Mt. Hermon @ Loomis-Chaffee, 4:00 pm
Milton @ Pomfret, 4:00 pm
St. George's @ St. Paul's, 4:00 pm
Kents Hill @ NYA, 4:00 pm
Berkshire @ Taft, 4:15 pm
Deerfield @ Williston-Northampton, 4:15 pm
Choate @ Hotchkiss, 4:30 pm
New Hampton @ Kimball Union, 4:30 pm
Millbrook @ Rye Country Day, 4:30 pm
Rivers @ Lawrence, 5:00 pm
Noble & Greenough @ Governor's, 5:30 pm
NE Falcons @ Kent, 5:30 pm
Tilton @ Proctor, 6:00 pm
Fri. Feb. 26
Southfield @ Rivers, 3:15 pm
Tabor @ Thayer, 4:00 pm
New Hampton @ Tilton, 4:15 pm
St. Paul's @ Holderness, 4:30 pm
Williston-Northampton @ Winchendon, 5:00 pm
Proctor @ Northfield Mt. Hermon, 6:00 pm
Berkshire @ Pomfret, 6:00 pm (rescheduled from 2/10)
Sat. Feb. 27
NYA @ Hebron, 12:00 pm
Greenwich @ Southfield, 12:00 pm
Newton Country Day @ EIL Tournament, time TBA
Rivers @ Tilton, 1:15 pm
Exeter @ Andover, 2:00 pm
BB&N @ Thayer, 2:00 pm
Gunnery @ Canterbury, 2:00 pm
Brooks @ Governor's, 2:00 pm
Groton @ St. Mark's, 2:00 pm
Stanstead College @ Holderness, 2:00 pm
Middlesex @ St. George's, 2:00 pm
Vermont Academy @ Kimball Union, 2:15 pm
Cushing @ Choate, 2:30 pm
Taft @ Hotchkiss, 2:30 pm
Millbrook @ Kingswood-Oxford, 3:00 pm
Northfield Mt. Hermon @ Brewster Academy, 3:45 pm
Loomis-Chaffee @ Deerfield, 4:00 pm
Noble & Greenough @ Milton, 4:00 pm
New Hampton @ Kents Hill, 4:00 pm
St. Paul's @ Lawrence, 4:15 pm
Pomfret @ Winchendon, 4:30 pm
Westminster @ Kent, 6:30 pm
Mon. 2/15/10
This Week's Schedule
Mon. Feb. 15
Millbrook @ Berkshire, 5:15 pm
NE Jr. Falcons @ Pomfret, 6:45 pm
Tues. Feb. 16
Choate @ Kingswood-Oxford, 4:30 pm
Wed. Feb. 17
Canterbury @ Millbrook, 2:15 pm
Northfield Mt. Hermon @ Williston-Northampton, 2:15 pm
Kent @ Hotchkiss, 2:30 pm
Middlesex @ Lawrence, 2:30 pm
Taft @ Westminster, 2:30 pm
NYA @ Kents Hill, 2:30 pm
Pomfret @ St. Mark's, 2:45 pm
Andover @ Noble & Greenough, 3:00 pm
Cushing @ Deerfield, 3:00 pm
Groton @ Brooks, 3:00 pm
St. Paul's @ BB&N, 3:15 pm
Southfield @ Newton Country Day, 3:30 pm
Choate @ Berkshire, 4:00 pm
Tabor @ Exeter, 4:00 pm
Brewster Academy @ Loomis-Chaffee, 4:00 pm
St. George's @ Milton, 4:00 pm
Holderness @ Vermont Academy, 4:00 pm
Kimball Union @ Tilton, 4:30 pm
Dana Hall @ Pingree, 4:30 pm
Hebron @ Proctor, 5:00 pm
Rye Country Day @ Morristown Beard, 5:00 pm
Berwick @ Winsor, 5:15 pm
Gunnery @ Greenwich, 5:15 pm
Rivers @ Governor's, 5:30 pm
Fri. Feb. 19
Rivers @ NYA, 3:00 pm
Pingree @ Newton Country Day, 3:30 pm
Southfield @ St. Paul's, 4:00 pm
Winsor @ Thayer, 4:15 pm
Dana Hall @ Portsmouth Abbey, 4:30 pm
Brewster Academy @ Exeter, 5:00 pm
Kents Hill @ Hebron, 5:00 pm
Vermont Academy @ Kingswood-Oxford, 5:00 pm
Milton @ Andover, 5:15 pm
Rice @ Kimball Union, 5:30 pm
Brooks @ Middlesex, 6:00 pm
Mid-Fairfield @ Gunnery, 6:45 pm
Sat. Feb. 20
Northfield Mt. Hermon @ Exeter, 1:30 pm
Winsor @ Portsmouth Abbey, 1:30 pm
Governor's @ Lawrence, 2:00 pm
Newton Country Day @ Berwick, 2:00 pm
Cushing @ Pomfret, 2:15 pm
Kents Hill @ Thayer, 2:15 pm
Berkshire @ Westminster, 2:30 pm
Kent @ Kingswood-Oxford, 2:30 pm
Brooks @ Tabor, 2:30 pm
Millbrook @ Greenwich, 2:30 pm
Groton @ St. George's, 2:30 pm
Canterbury @ Winchendon, 3:00 pm
Williston-Northampton @ Loomis-Chaffee, 3:00 pm
Hebron @ New Hampton, 3:00 pm
Tilton @ Vermont Academy, 3:00 pm
BB&N @ St. Mark's, 3:30 pm
Hotchkiss @ Deerfield, 3:30 pm
St. Paul's @ Noble & Greenough, 3:30 pm
NEWHL @ Holderness, 3:45 pm
Gunnery @ Southfield, 4:00 pm
Proctor @ Rivers, 4:00 pm
Choate @ Taft, 4:30 pm
Pingree @ Middlesex, 4:30 pm
Milton @ Brewster Academy, 5:00 pm
Mon. Feb. 22
Cushing @ Lawrence, 4:15 pm (rescheduled from 2/10)
St. George's @ BB&N, 4:30 pm (rescheduled from 2/10)
Gunnery @ Millbrook, 4:30 pm
Holderness @ New Hampton, 4:30 pm
Thayer @ Governor's, 5:00 pm (rescheduled from 2/10)
Noble & Greenough @ Groton, 5:00 pm (rescheduled from 2/10)
Brewster Academy @ Andover, 5:00 pm
Tues. 2/9/10 -- updates on Wed.
Wed. Postponements and Cancellations
There's a winter storm watch in effect for Connecticut and Massachusetts starting Wednesday morning and extending through late Wednesday night/Thursday morning. Snowfall amounts of over 12" are predicted, with less the farther north you go. We will have all the latest postponements and cancellations here. A note for coaches: please email information@ushr.com with the relevant info, and update your team's schedule on USHR in order to ensure that the changes appear on future weekly composite schedules. Thanks.
Wed. Feb. 10 Snow-outs:
Nobles @ Groton -- rescheduled to 2/22 (time TBA)
Thayer @ Governor's -- rescheduled to Mon. 2/22 at 5:00 pm
Kent @ Canterbury -- rescheduled to Thurs. 2/11 at 5:00 pm
Holderness @ Brooks -- rescheduled to Thurs. 2/11 at 4:00 pm
Cushing @ Lawrence -- postponed; no makeup date yet
Williston @ Choate -- no makeup date announced
St. Mark's @ Milton -- rescheduled to Fri. 2/12 at 4:30 pm
St. Paul's @ Middlesex -- rescheduled to Thurs. 2/11 at 5:00 pm
NMH @ K-O -- no makeup date announced
Taft @ Greenwich -- no makeup date announced
St. George's @ BB&N -- rescheduled to Mon. 2/22 at 4:30 pm
Berkshire @ Pomfret -- no makeup date announced
Hotchkiss @ Loomis -- no makeup date announced
Deerfield @ Westminster -- no makeup date announced
Winchendon @ Southfield -- rescheduled to Thurs. 2/11 @ 3:45 pm
Mon. 2/8/10
This Week's Schedule
Mon. Feb. 8
St. George's @ Portsmouth Abbey, 4:30 pm (postponed)
Tues. Feb. 9
Kent @ Canterbury, 4:00 pm
Rye Country Day @ Princeton Day School, 5:00 pm
Wed. Feb. 10
Exeter @ Kimball Union, 1:30 pm
Cushing @ Lawrence, 2:15 pm
Brewster Academy @ Proctor, 2:30 pm
Gunnery @ Millbrook, 2:30 pm
Williston-Northampton @ Choate, 3:00 pm
St. Mark's @ Milton, 3:00 pm
St. Paul's @ Middlesex, 3:00 pm
Noble & Greenough @ Groton, 3:30 pm
Northfield Mt. Hermon @ Kingswood-Oxford, 3:30 pm
Taft @ Greenwich, 3:30 pm
Vermont Academy @ Tilton, 3:30 pm
Tabor @ Andover, 3:45 pm
Thayer @ Governor's, 3:45 pm
St. George's @ BB&N, 4:00 pm
Berkshire @ Pomfret, 4:00 pm
Kent @ Canterbury, 4:00 pm
Hotchkiss @ Loomis-Chaffee, 4:00 pm
Hebron @ Berwick, 4:00 pm
Kents Hill @ New Hampton, 4:00 pm
Pingree @ Winsor, 4:15 pm
Deerfield @ Westminster, 4:30 pm
Holderness @ Brooks, 4:30 pm
Winchendon @ Southfield, 4:45 pm
Thurs. Feb. 11
Stanstead College @ Rice, 5:30 pm
Fri. Feb. 12
Governor's @ Andover, 4:30 pm
St. Paul's @ Tilton, 4:30 pm
BB&N @ Noble & Greenough, 5:00 pm
Rivers @ Cushing, 5:15 pm
Newton Country Day @ Portsmouth Abbey, 5:30 pm
N.E. Falcons @ Williston-Northampton, 6:00 pm
Southfield @ Proctor, 6:00 pm
Westminster @ Loomis-Chaffee, 6:30 pm
NEWHL @ Vermont Academy, 7:00 pm
Sat. Feb. 13
Exeter @ Brewster Academy, 12:00 pm
Proctor @ Holderness, 1:30 pm
Lawrence @ Thayer, 2:00 pm
Kingswood-Oxford @ Gunnery, 2:00 pm
Deerfield @ Berkshire, 2:15 pm
Tabor @ Pomfret, 2:15 pm
Governor's @ St. Paul's, 2:30 pm
Hotchkiss @ Taft, 2:30 pm
Middlesex @ Milton, 2:30 pm
St. Mark's @ Rivers, 2:30 pm
Kimball Union @ Williston-Northampton, 3:00 pm
Westminster @ Noble & Greenough, 3:15 pm
Brooks @ St. George's, 3:30 pm
Northfield Mt. Hermon @ Cushing, 4:30 pm
Kent @ Winchendon, 5:00 pm
Kents Hill @ Winchendon, 5:00 pm
Choate @ Loomis-Chaffee, 6:00 pm
Hebron @ Canterbury, 7:00 pm
Millbrook @ Kent, 7:00 pm
Sun. Feb. 14
Kents Hill @ Canterbury, 11:30 am
Exeter @ Brewster Academy, 12:00 pm
Hebron @ Winchendon, 1:00 pm
Mon. Feb. 15
Millbrook @ Berkshire, 5:15 pm
NE Jr. Falcons @ Pomfret, 6:45 pm
Mon. 2/1/10
This Week's Schedule
Mon. Feb. 1
Hebron @ NYA, 4:00 pm
Westminster @ Kingswood-Oxford, 5:00 pm
NEWHL @ Millbrook, 6:30 pm
Tues. Feb. 2
Tilton @ New Hampton, 4:30 pm
Wed. Feb. 3
Hotchkiss @ Berkshire, 2:00 pm
Tabor @ Rivers, 2:30 pm
Groton @ Middlesex, 2:30 pm
Proctor @ Vermont Academy, 2:30 pm
Andover @ Exeter, 2:45 pm
Brewster Academy @ Cushing, 3:00 pm
Loomis-Chaffee @ Gunnery, 3:00 pm
Taft @ Williston-Northampton, 3:00 pm
Thayer @ Brooks, 3:00 pm
Kimball Union vs. Kents Hill, 3:00 pm (@ Rochester, NH)
Canterbury @ Lawrenceville, 3:30 pm
St. Paul's @ St. Mark's, 3:30 pm
Stanstead College @ Tilton, 3:30 pm
Greenwich @ Kent, 4:00 pm
Lawrence @ Milton, 4:00 pm
Holderness @ Hebron, 4:00 pm
Noble & Greenough @ St. George's, 4:15 pm
Governor's @ BB&N, 4:30 pm
Westminster @ Pomfret, 4:30 pm
Berwick @ Pingree, 4:45 pm
Kingswood-Oxford @ Millbrook, 4:45 pm
Northfield Mt. Hermon @ Choate, 5:00 pm
NEWHL @ Deerfield, 6:30 pm
Thurs. Feb. 4
Princeton Day School @ Rye Country Day, 5:00 pm
Fri. Feb. 5
Pingree @ NYA, 4:00 pm
Hebron @ Middlesex, 4:30 pm
Cushing @ BB&N, 4:30 pm
New Hampton @ Vermont Academy, 4:30 pm
Northfield Mt. Hermon @ Kimball Union, 6:00 pm
Lawrence @ Tabor, 6:30 pm
Sat. Feb. 6
Taft vs. Andover, 12:30 pm (@ Harvard University)
Vermont Academy @ Northfield Mt. Hermon, 1:00 pm
Hebron @ Rivers, 1:00 pm
Kents Hill @ Southfield, 1:00 pm
Greenwich @ Winchendon, 1:00 pm
Winsor @ Berwick, 1:45 pm
Brooks @ Noble & Greenough, 2:00 pm
Thayer @ Portsmouth Abbey, 2:00 pm
Bay State Breakers @ Middlesex, 2:00 pm
Lawrence @ Groton, 2:30 pm
Governor's @ St. George's, 3:00 pm
Tabor @ St. Mark's, 3:30 pm
Pingree @ Tilton, 4:00 pm
Proctor @ Kimball Union, 4:30 pm
Holderness @ NYA, 4:30 pm
Sun. Feb. 7
Rice @ Stanstead College, 11:00 am
Mon. Feb. 8
St. George's @ Portsmouth Abbey, 4:30 pm
