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2014-2015 D1 "GRaNT" Computer Rankings

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  • 2014-2015 D1 "GRaNT" Computer Rankings

    More fun with Excel spreadsheets!

    I created my own computer ranking last night, called the GRaNT Computer Rankings -- (Stands for "Grant's Reasonable and Not Terrible Computer Rankings"). Pretty exciting stuff. here is the link to the ranking..

    Here's the jist of the rankings:

    -All teams are assigned an arbitrary rating. It doesn't matter what you use because the rankings will come out the same regardless of what you start with. Since it doesn't matter, the calculator literally starts each team out with a RAND() value.

    -Each team's rating is recalculated based on their winning percentage and their opponent's rating as follows:
    ---A win adds the opponent's rating
    ---A loss adds zero
    ---A tie adds 1/2 the opponent's rating
    ------The sum is divided by the number of games played, and then adjusted to equal the percent of the average of the new ratings.

    The GRaNT Rankings are constructed somewhat similarly to KRACH in that it uses each team's ranking to calculate everyone else's ranking. I'll explain.

    Example: Teams A, B, and C each play each other once each.

    Team A's starting rating: 0.666
    Team B's starting rating: 0.444
    Team C's starting rating: 0.222

    Team A beats Team B and ties Team C. Team A's new unadjusted rating is (0.444+0.111)/2=0.278.

    Team B beats Team C and loses to Team A. Team B's new unadjusted rating is (0.222+0)/2=0.111

    Team C ties Team A and loses to Team B. Team C's new unadjusted rating is (0.333+0)/2=0.167

    The average of the new ratings is (0.278+0.111+0.167)/3=0.185

    So, each team's new rating is:

    Team A: 0.278/0.185=1.503
    Team B: 0.111/0.185=0.600
    Team C: 0.167/0.185=0.902

    Then the process repeats itself, recalculating based on the new ratings instead of the starting rating. Each team's rating will converge to a different number such that when you recalculate, you get the same number:

    Team A: 0.6190/0.4491=1.3784 (percent of average)
    Team B: 0.3837/0.4491=0.8544
    Team C: 0.3446/0.4491=0.7673

    Team A: (0.8544+0.38365)/2=0.6190
    Team B: (0+0.7673)/2=0.3837
    Team C: (0.6892+0)/2=0.3446

    -- and those convergent values are each team's final rating.

    That final rating is scaled to make zero equal average, and ranked, naturally, from best to worst. The result is the GRaNT Rankings.

    You'll notice that teams are awarded 0 points for a loss, no matter who they play -- that means that teams are not penalized for losing to good teams, since all losses count the same. The end result is that teams are rewarded for playing and beating good teams, not penalized for playing but losing to good teams.

    It also means that teams are not overly penalized for bad losses. In this way, the ranking is more focused on how good your team can be, not how bad your team can be.

    I feel that come tournament time, when teams are focused and playing at their highest level, this will be a better indicator for success than overly penalizing them for a couple of bad mid-season losses when not playing at their full potential.

    Anyway, let me know what you think!
    Last edited by TonyTheTiger20; 01-28-2015, 09:28 AM.
    Grant Salzano, Boston College '10
    Writer Emeritus, BC Interruption
    Twitter: @Salzano14


    Click here for the BC Interruption Pairwise, KRACH, and GRaNT Calculators

  • #2
    Originally posted by TonyTheTiger20 View Post
    More fun with Excel spreadsheets!

    I created my own computer ranking last night, called the GRaNT Computer Rankings -- (Stands for "Grant's Reasonable and Not Terrible Computer Rankings"). Pretty exciting stuff. I will post a BCI link with an easy-to-read ranking in the next couple days, but here is a temporary link.

    Here's the jist of the rankings:

    -All teams are assigned an arbitrary rating. I used .500 but it doesn't matter what you use because the rankings will come out the same regardless of what you start with.

    -Each team's rating is recalculated based on their winning percentage and their opponent's rating as follows:
    ----A win adds the opponent's rating
    ----A loss adds zero
    ----A tie add's 1/2 the opponent's rating
    ------The sum is divided by the number of game's played.

    Example: Teams A, B, and C each play teams X Y and Z once each.

    Team A beats Team X, loses to Team Y, and ties Team Z. With starting value of 0.500 for everyone, Team A's new rating is ( 0.500 + 0 + 0.250 ) / 3 = 0.25.

    Team B wins all 3 games. Team B's new rating is ( 0.500 + 0.500 + 0.500 ) / 3 = 0.500

    Team C wins against Teams X and Y but loses to Team Z. Team C's new rating is ( 0.500 + 0.500 + 0 ) / 3 = 0.333

    -That is done for all teams, and the new rating assigned to each team.


    Then, the system restarts again with all of the new ratings instead of 0.500. It's done over and over until the ratings converge.

    These are the rankings after the games of 1/24. I think Minnesota ends up leapfrogging BC with Wisconsin's win over Clarkson; I'll post an update once all the games are done.

    Code:
    Rank Team	       Rating
    1    Boston College    0.8834
    2    Minnesota	       0.8769
    3    Wisconsin	       0.7308
    4    Quinnipiac	       0.6364
    5    Harvard	       0.6045
    6    Boston University 0.5902
    7    St. Lawrence      0.5463
    8    Clarkson	       0.5440
    9    Cornell	       0.5398
    10   Minnesota-Duluth  0.5285
    11   Bemidji State     0.5237
    12   Mercyhurst	       0.4539
    13   Ohio State	       0.4536
    14   North Dakota      0.4528
    15   Dartmouth	       0.3992
    16   Penn State	       0.3853
    17   Princeton	       0.3569
    18   Northeastern      0.3192
    19   Maine	       0.3086
    20   Syracuse	       0.3053
    21   Vermont   	       0.2967
    22   Robert Morris     0.2661
    23   RIT	       0.2541
    24   Yale	       0.2451
    25   Lindenwood	       0.2318
    26   Connecticut       0.2231
    27   Brown	       0.1959
    28   New Hampshire     0.1939
    29   Providence	       0.1909
    30   Rensselaer	       0.1600
    31   Colgate           0.1597
    32   Union	       0.1552
    33   St. Cloud State   0.1539
    34   Minnesota State   0.0579
    The one thing that ends up happening here is that you aren't really penalized for losing to good teams. A loss to the team in last place and a loss to the team in first place both affect your rating the same -- you get 0 points divided out by the extra game.

    However, you are rewarded big time for playing really good teams -- you get a big boost to your rating for a win and aren't really hurt that much for a loss.

    Anyway, let me know what you think!
    BC #1?! Seems like fuzzy math

    Comment


    • #3
      Re: 2014-2015 D1 "GRaNT" Computer Rankings

      Excellent contribution.

      Any ranking system based on a rational examination of results on the ice is welcome. As with any system the assumptions at the base of the system are the only arguing point but I personally find no fault with your assumptions here.

      The building of this ranking system clearly has taken more than the 4 or 5 minutes per week that most of us put into our personal rankings. I fear that either your employer or your family has borne the brunt of time lost from the time they expected of you. From what I know of you and from comments you have made here I suspect in this case your employer is the larger loser. If that is so I counsel you to be careful. But looking at the overall project and the personal resources that you have brought to the project I suspect that you are also bringing more than enough to the employer's table to justify the pittance that they pay you, probably considerably less than you deserve.

      Very nice work.

      Be very sure to take good care of your family.
      Pay no attention to the man behind the curtain.

      Comment


      • #4
        Re: 2014-2015 D1 "GRaNT" Computer Rankings

        WOW well thank you, that is easily the nicest thing someone has said to me here!

        Fortunately I actually did this one on the weekend with no time lost at work... for once
        Grant Salzano, Boston College '10
        Writer Emeritus, BC Interruption
        Twitter: @Salzano14


        Click here for the BC Interruption Pairwise, KRACH, and GRaNT Calculators

        Comment


        • #5
          Re: 2014-2015 D1 "GRaNT" Computer Rankings

          Here are the updated ratings for today -- also I changed the scaling so that "0" means average. Same exact formula just scaled differently.

          BC and Minnesota are so close that Wisconsin's win today over Clarkson moved Minnesota back on top.

          Rank Team Rating
          1 Minnesota 49.98
          2 Boston College 48.71
          3 Wisconsin 37.08
          4 Quinnipiac 24.53
          5 Harvard 21.21
          6 Boston University 20.26
          7 St. Lawrence 15.25
          8 Cornell 14.52
          9 Minnesota-Duluth 13.92
          10 Clarkson 13.27
          11 Bemidji State 12.45
          12 North Dakota 9.56
          13 Mercyhurst 6.33
          14 Ohio State 6.10
          15 Dartmouth 0.70
          16 Penn State -0.51
          17 Princeton -3.32
          18 Maine -6.44
          19 Syracuse -8.23
          20 Northeastern -8.33
          21 Vermont -9.91
          22 Robert Morris -12.43
          23 RIT -13.59
          24 Yale -14.54
          25 Connecticut -15.79
          26 Lindenwood -15.91
          27 Brown -19.09
          28 New Hampshire -19.50
          29 Providence -20.37
          30 Rensselaer -22.84
          31 Colgate -22.99
          32 Union -23.23
          33 St. Cloud State -23.68
          34 Minnesota State -33.18
          Grant Salzano, Boston College '10
          Writer Emeritus, BC Interruption
          Twitter: @Salzano14


          Click here for the BC Interruption Pairwise, KRACH, and GRaNT Calculators

          Comment


          • #6
            Re: 2014-2015 D1 "GRaNT" Computer Rankings

            Originally posted by TonyTheTiger20 View Post
            WOW well thank you, that is easily the nicest thing someone has said to me here!

            Fortunately I actually did this one on the weekend with no time lost at work... for once

            Really cool

            Comment


            • #7
              Re: 2014-2015 D1 "GRaNT" Computer Rankings

              My guess is that this one performs better as the season progresses. Early, it would be at the mercy of the unbalanced schedule, such that late starters like the Ivy League teams would be more undervalued than usual.
              "... And lose, and start again at your beginnings
              And never breathe a word about your loss;" -- Rudyard Kipling

              Comment


              • #8
                Re: 2014-2015 D1 "GRaNT" Computer Rankings

                This is somewhat similar to the way that KRACH is calculated, especially in its approach of trying to derive a team's rating from its expected outcome in each individual game. Th main conceptual difference is that KRACH weights losses by the quality of the opponent as well as the wins, which I think is a strength of KRACH. On the other hand, the calculations are much simpler in this method so people have a better idea of what is actually happening in the process.

                Comment


                • #9
                  Re: 2014-2015 D1 "GRaNT" Computer Rankings

                  Originally posted by ARM View Post
                  My guess is that this one performs better as the season progresses. Early, it would be at the mercy of the unbalanced schedule, such that late starters like the Ivy League teams would be more undervalued than usual.
                  Of course -- what ranking wouldn't?

                  (Other than Rutter, who includes previous season results early in the season and gradually weans them out)
                  Grant Salzano, Boston College '10
                  Writer Emeritus, BC Interruption
                  Twitter: @Salzano14


                  Click here for the BC Interruption Pairwise, KRACH, and GRaNT Calculators

                  Comment


                  • #10
                    Re: 2014-2015 D1 "GRaNT" Computer Rankings

                    Originally posted by Eeyore View Post
                    This is somewhat similar to the way that KRACH is calculated, especially in its approach of trying to derive a team's rating from its expected outcome in each individual game. Th main conceptual difference is that KRACH weights losses by the quality of the opponent as well as the wins, which I think is a strength of KRACH. On the other hand, the calculations are much simpler in this method so people have a better idea of what is actually happening in the process.
                    I really wish there was some kind of explanation for how KRACH is calculated. I mean I know there are explanations for what the numbers mean and that it's an iterative process and whatnot, but I haven't been able to actually find the method used to carry out the process. Same with Rutter and WCHODR. Great rankings, I assume, but I wanna know the nuts and bolts!

                    That's exactly almost entirely why I was motivated to create my own.
                    Grant Salzano, Boston College '10
                    Writer Emeritus, BC Interruption
                    Twitter: @Salzano14


                    Click here for the BC Interruption Pairwise, KRACH, and GRaNT Calculators

                    Comment


                    • #11
                      Re: 2014-2015 D1 "GRaNT" Computer Rankings

                      Originally posted by TonyTheTiger20 View Post
                      I really wish there was some kind of explanation for how KRACH is calculated.
                      Have fun. There's a reason I tend to talk in analogies when trying to describe what KRACH is doing.

                      Comment


                      • #12
                        Re: 2014-2015 D1 "GRaNT" Computer Rankings

                        Originally posted by TonyTheTiger20 View Post
                        I really wish there was some kind of explanation for how KRACH is calculated. I mean I know there are explanations for what the numbers mean and that it's an iterative process and whatnot, but I haven't been able to actually find the method used to carry out the process. Same with Rutter and WCHODR. Great rankings, I assume, but I wanna know the nuts and bolts!

                        That's exactly almost entirely why I was motivated to create my own.
                        TTT,

                        I grabbed this for you to read on how KRACH works

                        KRACH is short for “Ken's Rating for American College Hockey.” Ken is Ken Butler, a statistician, and the mathematical model he used is known as the Bradley-Terry Rating System. The system and its details are well documented in great mathematical detail online (see KRACH explanation at Ken Butler's homepage).

                        http://www.mghca.com/page/show/427504-krach-rankings. Click on the KRACH were it says explanation at Ken Butler's homepage.

                        Comment


                        • #13
                          Re: 2014-2015 D1 "GRaNT" Computer Rankings

                          Oh you guys are just the best.

                          I'm glad this was after I created my own system, maybe I wouldn't gave felt like I had to lol
                          Grant Salzano, Boston College '10
                          Writer Emeritus, BC Interruption
                          Twitter: @Salzano14


                          Click here for the BC Interruption Pairwise, KRACH, and GRaNT Calculators

                          Comment


                          • #14
                            Re: 2014-2015 D1 "GRaNT" Computer Rankings

                            I officially published the new ranking on BCI, and created a men's hockey version as well -- here's the link with a better explanation of how it's calculated and why.

                            http://www.bcinterruption.com/boston...aa-frozen-four

                            Also I removed the "multiply by 100" scaling, there wasn't really a reason for it.
                            Grant Salzano, Boston College '10
                            Writer Emeritus, BC Interruption
                            Twitter: @Salzano14


                            Click here for the BC Interruption Pairwise, KRACH, and GRaNT Calculators

                            Comment


                            • #15
                              Re: 2014-2015 D1 "GRaNT" Computer Rankings

                              I find it interesting that you list the men first

                              also, you have so much data and so many ads, I think you are shooting yourself in the foot if your goal is to have as many people as possible access your site, many people don't have much patience

                              kind of reminds me of the myspace days when people would put so much crap in the background that the message they were trying to convey got lost

                              on the one hand, I appreciate any new ranking system because it makes mine more accurate (in theory) however, looking at your rankings makes me question how much validity it has

                              Comment

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