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  • How is the percentage calculated?

    On the contest results, there is a percentage number under your sequence score. Can someone enlighten me as to how this is calculated? I have crunched a bunch of numbers and can not get the same percentage as what is shown on the results sheet.

    Thank you!

  • #2
    It appears to be very close to adding the raw scores and dividing by 120 (max possible). But it is not exact. I would think that a K-Factored version of this would be more representative...
    Rich
    Krzy4RC
    #IAmIMAC
    Newsletter Editor
    @RC Aerobatics Podcast

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    • #3
      So this is what was come to back when PP also known at Points of Perfection or Perfection Points or a few others actually. This is also how we rank Bennett Cup, Schroder Cup and Seniors in variations. The original idea was to include Unknowns when it was launched but this was met with some resistance of Webmaster at the time. He felt only knowns should be included and not Unknowns and also did not find it viable across International regions for a host of reasons as well. But the then BOD did vote (not eliminating IRPS) to give PP a look. We just felt it should indeed include Unknowns and across International as well as US and Canada.

      Boiled down it is indeed your percentage of a perfect 10 across the sequence. PP also does not allow drops so when used for items currently like the Bennett or Schroder cup, it is exactly what is used to calculate those winners and rankings.

      Where IRPS has a normalization to your best flight each round receiving the 1000 points and each "prorated" if you will down from 1000.

      When this was worked thru with Mike Karnes myself and Dan Carroll and eventually integrated in the website in a broader stroke than intended we had the final math Mike and I had done with it and Dan Carroll double checked by Kurt Koelling and his resulting statement was mathematically our Score Program was calculating to 6 from the decimal at spot on!!


      How it was used on previous website below.

      Hope that is as clear as mud.



      Pilot Percentage


      The ability to compare flying skills is the core of IMAC competition. For years, IMAC pilots have looked for a way to compare their performance against their peers across regional and international boundaries. Recently IMAC incorporated a “Percentage of Perfect” to the Score 4.25.1 program that shows how pilots performed relative to the total possible points available for a sequence.

      With that addition also came the ability to compare pilot to pilot performance across large geographic regions (in this case, the entire world). The latest SCORE version automatically calculates the PP for each pilot and the IMAC web scoring system has been updated to allow all IMAC members to compare their scores/skills to every other IMAC member in the world. The system allows filtering to display results by class or IMAC region. Although there are many variables unaccounted for in this method, IMAC is providing each pilot with the AVERAGE of ALL their scores through the season for KNOWN sequences only. This method does not include UNKNOWNS at this time, and uses ALL scored KNOWN sequences. The reasoning is, Knowns follow a common drop schedule allowing the pilot to drop low rounds particularly in the case of mechanical difficulty, etc. Unknowns are still vital to contest results but normally cannot be dropped and may vary from event to event, the best comparison basis is by restricting the formula to only consider KNOWNS. So for now it will NOT be an ALL INCLUSIVE ranking system.

      Regional points are NOT affected by PP Data. The IRPS continues to be the IMAC standard to compare the ranking of pilots within the 6 U.S. Regions

      Doug Pilcher

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      • #4
        Then I don't think the score sheets calculate it perfectly. Some of it is a little off.
        Rich
        Krzy4RC
        #IAmIMAC
        Newsletter Editor
        @RC Aerobatics Podcast

        Comment


        • #5
          What Doug said :-)

          I would also add that we've had a few iterations of this and apart from including the unknowns you also have to consider if dropped rounds are included.
          But you don't want to ignore traditionally dropped rounds because you might have flown your best round but it still gets dropped because others flew that much better...

          What we do now is calculate each round and apply the same drop schedule to the percentage scores.
          So if you end up flying enough to drop 2 rounds then your worst two are dropped (not your worst two normalised!).

          Also, I'd have to check the code (I tend to forget the details of complicated math after a year or so) but we either calculate the percentage based on raw scores or we k-factor them first.
          I think we k factor them first and I am not 100% but I think we might also apply the pilot/panel penalty. I'd have to check.

          I've had a few times over the years where we've done a manual calculation to make sure it's correct and all I can say is that when we check directly and apply the same rules manually as what was put into the code, the numbers are correct.

          Having said that, I'm keen to double check anytime someone wants to so if you have an example of one that is a head scratcher, lets dig into it for the exercise...

          Comment


          • #6
            Here's a run down of the score for a single pilot for one round...
            3 Judges...

            I hope it's a little clear? Basically you calculate the K Factored score for each figure, add them together and divide by the number of judges.
            Then you divide that by the largest possible K Factored score you can get.

            Rounded to 1 decimal place.

            In my example the Jx/S are the scores. And the Jx/K are the K Factored equivalents...

            Click image for larger version

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            Last edited by Dan Carroll; 11-23-2022, 04:18 AM.

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            • #7
              Thanks for asking the question Mark. It's good to remind myself how this works and it's always possible I've been doing it wrong all these years, so more people verifying the calcs is a good thing. ;-)

              Comment


              • #8
                Originally posted by Rich Whitlow View Post
                Then I don't think the score sheets calculate it perfectly. Some of it is a little off.
                Do you have an example? I'm always open to finding and fixing problems where they exist...

                Comment


                • #9
                  Here is an example

                  Click image for larger version  Name:	Jimmy Allen.jpg Views:	0 Size:	23.9 KB ID:	5876

                  Raw judges Scores:

                  Click image for larger version  Name:	Jimmy Allen Data.jpg Views:	0 Size:	105.4 KB ID:	5878

                  Calcs with excel:

                  Click image for larger version  Name:	Jimmy Allen Excl Calc.jpg Views:	0 Size:	13.5 KB ID:	5877

                  The 80.4 matches, but the 81.25, shows as 81.8.

                  I can send the complete docs to you if you like (or the score folder)

                  Rich
                  Rich
                  Krzy4RC
                  #IAmIMAC
                  Newsletter Editor
                  @RC Aerobatics Podcast

                  Comment


                  • #10
                    Originally posted by Rich Whitlow View Post
                    The 80.4 matches, but the 81.25, shows as 81.8.

                    I can send the complete docs to you if you like (or the score folder)

                    Rich
                    In your example, column J1 is Judge 1 Seq1. Column J2 are the scores from J1 Seq 2.
                    You need to look below for J2 Seq 1.



                    Click image for larger version

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                    I have always hated that part of the HTML report. That's one of the reasons I created the Mobile report:




                    Click image for larger version

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                    • #11
                      I messaged Dan with my Tucson score sheet and he squared me away with 1 sentence, "You then average ALL 3 judges" DUH!!! I was just doing 1 judge.

                      Thank you for straightening me out Dan!

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                      • #12
                        All good Mark! :-)

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                        • #13
                          The math is right I promise. When we did all of this, Karnes and I ran 100's of contests thru it. The Math works.


                          Forget the 1000 points. Think how well did I actually fly compared to perfect?
                          Doug Pilcher

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                          • #14
                            Originally posted by Doug Pilcher View Post
                            Forget the 1000 points. Think how well did I actually fly compared to perfect?
                            That is what I was working on figuring out and strayed off course just a little

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