Hawk Eye Challenge System has Arrived!

Discussion in 'Rules / Tournament Regulation / Officiating' started by Tactim, Apr 4, 2014.

  1. craigandy

    craigandy Regular Member

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    Here you go fill your boots:) http://www.isb.ac.th/HS/JoP/vol4iss2/jun10.html
     
  2. Pakito

    Pakito Regular Member

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    wow, all these albert einstein parameters is making me cross-eyed. This just goes to show how complicated the flight path of a shuttle is, compared to the tennis ball. I just hoped that at the end of the day, we don't find out that the heralded hawk-eye was all the while making errors in judgement.

     
  3. visor

    visor Regular Member

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    The computer algorithm doesn't have to know those formulae and parameters, it just analyzes the data based on a huge pool of previously collected data, and attempts to interpolate and extrapolate the data points to track where the projectile is at any given moment in time.

    The only problem we can see is that the shuttle's contact point is so much smaller than the tennis ball that the error tolerance becomes a relatively larger percentage.
     
    #123 visor, Apr 15, 2014
    Last edited: Apr 15, 2014
  4. pcll99

    pcll99 Regular Member

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    Very true. The size of the contact point is about the same as the margin of error. :eek:
     
  5. renbo

    renbo Regular Member

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    I wonder how the computer can guess how much slice is given to a smash, because the slice change the way the shuttles decelerates, and it is only passed the net the the effect begins to show.
     
  6. RedShuttle

    RedShuttle Regular Member

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    The flight path is not a big issue. In theory, if the frame rate is high enough, i.e. the path needs to be calculated is short enough, even a simple linear extrapolation is sufficiently accurate.

    My biggest concern is on determining the posture/bearing of the shuttlecock. The tennis ball is round. It does not matter which part touches down first. The badminton shuttlecock is a lot more complicated and as pointed out by others, the tolerable margin of error is a lot smaller in badminton.

    BWF acted too hastily in adopting Hawk-Eye for badminton. Hawk-Eye may work, but there is still a long way to go.
     
  7. okooko

    okooko Regular Member

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    If you can 3D track the shuttle or at least the cork, the systems will follow the change in acceleration and direction, so smashes/slices/etc will have different velocity profiles.

    Dno if its hawkeye but theres this thing in cricket that shows the projectile of the ball even if its hit going past the stumps to see if it was LBW.
     
  8. Oldhand

    Oldhand Moderator

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    Yes, that is Hawk-Eye.
     
  9. SigH-Max

    SigH-Max Regular Member

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    Caught up with the SO games. Cock-Eye system is ridiculously inaccurate, get rid of it. One simple example is to look at its assessment after a lift, and see the odd error mark: the ellipse is quite flat, it should rather be more round (compared to one mark after a smash), how on earth can the algorithm be that poor?
    One such example is visible in the MS final. In that game, by the way, most the computed trajectories looked off.
     
  10. Tactim

    Tactim Regular Member

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    A little update on hawkeye. Not sure how many of you have been paying attention to it, but it's made vast improvements over the last few months. The impact is now completely circular with no more flat ellipses. The animations seem improved over the projected shuttle flight (coming downward after a lift or at an angle during a smash.

    I haven't seen any ridiculous challenges that were extremely off during the last couple tournaments.

    I hope it stays this way. I wish they would have gotten this right the first time and delayed hawkeye for three months to get to this level.
     
  11. craigandy

    craigandy Regular Member

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    https://www.youtube.com/watch?v=N8FBwDYRrKE
    1.08:10 - 1.09.00 The animation is obviously still an invention. Don't really get it, surely if they are tracking the shuttle just put the exact mapping of it on the animation like tennis, what's the point in this made up animation?
    That impact shadow is suspect also, wonder how they went about getting that. Looks too big and I am not sure it has the right point based on the different angles of the shuttle.
    But yeah, there is improvement I suppose.
     
  12. visor

    visor Regular Member

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    Agreed. There's been significant improvement in how soon the replay is done, and how realistic the contact point is, and how accurate the Hawk-Eye calls are.

    I can only recall one incident where Morten and Gill and I thought that Hawk-Eye was visibly incorrect.

    A vast improvement. And hopefully BWF will listen to Gill's call for 2 challenges per game instead of per match.
     
  13. kbase

    kbase Regular Member

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    Though it is a very welcome step and significant improvement for a fairer game, hawk eye system is most welcome in Badminton . But how the technology do it ? I do see all the replies pointing only to the cork ( ie base of the shuttle and not the feathers ). The probability of the shuttle landing the court with feathers first is high especially during smashes. Even in tosses to back boundary line, there are chances that shuttle might land with the feather rather than the cork. How does the technology address this ?

    For tennis it works well as it is a ball and they are more accurate in prediction
     
    #133 kbase, Jun 30, 2014
    Last edited: Jun 30, 2014
  14. visor

    visor Regular Member

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    Try it yourself, due to aerodynamics, it'll never ever land on the feathers first. Maybe on a tumbling net shot that rolls down the net.
     
  15. kbase

    kbase Regular Member

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    For tosses, chances are very rare or it won't due to aerodynamics. How about smashes ?
     
  16. visor

    visor Regular Member

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    Same. Cork first always.
     
  17. Stealthking

    Stealthking Regular Member

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    Agree with Visor....physically the shuttle will always lead with the cork in flight. Even tumbles at the net, the final drop path will lead with the cork. Maybe I have too much time on my hands, but I dropped a shuttle 50 times from 3 feet with feather facing the floor and could never get the feather to hit the ground first.....just a basic test but solved my curiosity
     
  18. visor

    visor Regular Member

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    Hehe... since you have some time, why not check to see what's the maximum drop height in order for the bird to land on the *feathers*, dropping with the bird feather down ... :)
     
  19. Stealthking

    Stealthking Regular Member

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    LOL... great minds think alike.... Yeah, at below 3 feet, you get every third or so shuttle hitting side on. So that being said, the lowest point of the net is around that point so the shuttle will always land cork first.

    Consider that when I drop it, I am holding it perfectly with cork pointing upwards and feathers downwards, but in tumbling shots off the net, any movement will result in the shuttle turning cork down due to its weight distribution. So even at around 2.5 feet, if I don't have it perfectly upside down, it will still hit cork first.....
     
  20. visor

    visor Regular Member

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    ^ Cool to know... Tks!
     

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