Calculate your serve speed

Discussion in 'Other Equipment' started by tennisplayer_85, Nov 12, 2012.

  1. LeeD

    LeeD Bionic Poster

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    I gave you all the variables, and you saw the "spin".
    Oh sorry, another newbie poster.
    Welcome to TW forrums, without you newbies, the forums will die out.
    Wind. I had long hair. No wind, no hair blowing around.
     
  2. spinorama

    spinorama Rookie

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    Well I mean, I can kick serve 2nd serve and hit the fence every time before bounce, or smash a 1st at 125 and hit the fence in the same spot. So I just think the radar is the only way.
     
  3. LeeD

    LeeD Bionic Poster

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    "you saw the vid"....
    Those serves were a semi flat serve with some amount of topspin because that early in the season, I couldn't find my grip.
     
  4. LeeD

    LeeD Bionic Poster

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    YOU can hit 125 flat serves AND twists that hit the wide baseboard around 24-36" high?
    You're a better man than me.
     
  5. spinorama

    spinorama Rookie

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    Yeah, I've never really focused on how high up the fences it hits, but I'll pay more attention to that next time I'm out there. I'm thinking 2-3 ft sounds right sometimes more sometimes less
     
  6. LeeD

    LeeD Bionic Poster

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    So, do you have the biggest serves at the courts you play at?
    My paltry "100 mph" flat serves bouncing around 34" high average is about the fastest at the two courts I frequent, which includes about 50 different players.
    The local 5.5 guy, and his 6'3" brother, don't have faster first serves.
     
  7. spinorama

    spinorama Rookie

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    Generally yeah. But I mean I'm 25 years old 6'2 and 195lbs so it's not weird that serving is my power
     
  8. spinorama

    spinorama Rookie

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    I'm surprised the 5.5 doesn't break 100mph..
     
  9. tennisplayer_85

    tennisplayer_85 New User

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    Recording the tv might work, i actually havent tested it, though it will be less accurate because tv's in general are 30 fps. If the input is 30 fps which you will record with 60 fps i suspect you will loose some accuracy.

    I did test the app very well with real videos from the australian open in which the speedgun shows the speed. I did posts these results in this thread.
     
  10. LeeD

    LeeD Bionic Poster

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    The 5.5 serves with either hand, hits top/slice on first serves, avoids flat serves for some reason.
    His brother, taller at 6'3", also avoid hitting flat serves, even in practice with tons of balls. Don't know why, but it's their game to fiddle with. Both hit with two forehands, but do have a rightie backhand slice.
     
  11. Chace

    Chace Semi-Pro

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    Has anybody tried this ap that has had their serve clocked by a radar gun? If so how accurate is the ap in comparison to when you were clocked with the radar gun?
     
  12. JackB1

    JackB1 G.O.A.T.

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    I don't understand how this can be accurate? Because you approximate the spot you are serving from and you also approximate the spot the ball hits on the court. Also, where you stand isn't where you contact the ball. Some guys hit the ball 2 feet inside the baseline and some guys hit it from behind the baseline.
     
  13. tennisplayer_85

    tennisplayer_85 New User

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    Yes it is true that there is some human error and that this affects the accuracy, but it’s not as bad as you think. Imagine you serve from the baseline to the service box line, which is exactly 60 feet.
    Now you move the player 1 foot to the right because of human error.

    If we use Pythagoras (a2 + b2 = c2) we can calculate the new distance 60(2) + 1(2) = 60.0083 feet.

    A good formula is used to calculate at which height the player hits the ball. Imagine you hit the ball a foot higher than average. This means again that there is 0.0083 human error.

    As you can see, moving the player or the ball horizontally and even the players height does almost not affect the speed at all.

    Since the iPhone has a 60FPS camera the time factor is very accurate as well and almost does not give any room for error.

    The only error is as you say, if the player hits the ball a foot inside the court, because this does affect the speed. The 60 feet distance would become 59 feet.
    Which is 1.667% error. So if a player would serve 100 mph the serve would be 101,6 mph.

    So let’s say there is an error range about 2,5 miles or maybe a bit more but on average it wont be this bad. In my opinion this is very reasonable.

    Also hold in mind that a speed gun (even the professional ones) have an error range too and need to be calibrated and are sometimes inaccurate.
     
  14. JackB1

    JackB1 G.O.A.T.

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    Thanks for the reply. I think the bigger issue though is how u have to estimate the spot where the serve hit the court. I tried moving the spot around just a little bit and got readings as much as 10 mph apart. That's just a bit too large of a variance to make the app useful.
     
  15. NLBwell

    NLBwell Legend

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    If you take multiple samples, you will converge on an average (it should be a normal distribution).
     
  16. JackB1

    JackB1 G.O.A.T.

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    of course I can take an average. but that doen't make it any more accurate.
     
  17. tennisplayer_85

    tennisplayer_85 New User

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    As explained in the previous comment, moving the spot where the ball hits (lands on) the court horizontally almost doesn't have any effect on the speed.
    Moving the ball 1 foot in the vertical direction does by 1.6 miles of error (see previous comment). So the 10 miles you talk about would mean moving the ball more than 6 feet from it's real landing location. In normal circumstances you should be able to guess the balls location within a foot of its real location (especially if its close to the lines).

    I have tested it with real videos from the australian open where the professional radar gun shows the speed so i was able to compare. All the calculations i did where within 2,5 miles of the radar gun's speed except for 1 out of 10, I suggest you try it your self at a pro tournament.

    It would still be really nice to overcome the 'human error' of this step and i do have a way to reduce it! the idea is to overlay the 4 corners of the servicebox and then transfer the balls location from 1 dimension to the real dimension of the court. I am confident that this will be quite accurate. I hope to come with an update with this functionality, but give me some time :)
    Anyway i think the App, as how it is, is the most accurate we can get with today's smartphones. And i still think the 2.5 miles error is not bad at all!
     
  18. v-verb

    v-verb Hall of Fame

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    Agreed. Don't let the naysayers get to you.

    If I could ever find my iPod touch I'll buy it - dying to try the app!
     
  19. Tight Lines

    Tight Lines Professional

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    The calculations are based on formulas from http://www.donthireddy.us/tennis/speed.html. That website has a calculator that calculates the speed for you. All you need is the frame rate of your camera and the number of frames it takes from the time the ball leaves the racket and the time it hits the ground.

    The app basically does the same thing, but makes inputting data much easier.

    I have used the app many times now for me and my friends, and believe that it is reasonably accurate although I have never compared it to a radar gun.

    --- Harry
     
  20. dlesser13

    dlesser13 Rookie

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    I serve faster than LeeD and the majority of posters on this board.
     
  21. LeeD

    LeeD Bionic Poster

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    ..and you're proud of serving faster than a 64 year old who's suffered thru 2 broken left collarbones, two separations of the left shoulder, one dislocate, has torn tendons in his left ankle, has 5 pins total in pinkie and ring finger of his left hand, and hadn't run one step in 4 years before the vid was taken?
     
  22. Tamiya

    Tamiya Semi-Pro

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    R u in melbourne? If so we might be able to tie up some real world testing.
    I have a Bushnell Speedster k-band & know a friend who's bought
    the 2-digit huge LED radar thingy that you'd hang on the back fence.

    Just need to find a court & someone with a strong reliable repeatable serve...
     
  23. LeeD

    LeeD Bionic Poster

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    What I don't understand is why doesn't anyone who's radaring himself or app speed calculating himself ever say how high his serves bounce, or whether it's the fastest of the courts they play on?
    It's either or, not both.
    In my case, I claim "100", and you saw my serviing vids. My wide serves, out at the intersect of service line and singles sideline bounce around 30" high on the backboard, 21' behind the baseline, with DunlopHD balls and 62 degree air temps.
     
  24. tennisplayer_85

    tennisplayer_85 New User

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    Just to let you know out here, ServeSpeed v2.2 has been available for the last weeks. Some Major improvements:

    -Added grid overlay on top of the service box, 1x1 foot.
    -By dragging the ball, the distances from each line will be shown.

    Since there was some discussion on the accuracy determining the ball's landing location. This update seriously improved that part.
     
  25. Shroud

    Shroud Hall of Fame

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    Where do you set the phone up to take a useful vid?

    I swear I saw some instructions at one point but now I cant find them on the site or the app for that matter.

    CLosest is a vid from the court you are serving to. how can I set the phone up to capture that and still actually see the ball? Can you film from the side or back?

    DO you need a tripod, etc?
     
  26. Cup8489

    Cup8489 Legend

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    Is this on Google play store too?
     
  27. Shroud

    Shroud Hall of Fame

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    No one knows. Is there a tripod for the iphone I can get?
     
  28. Tight Lines

    Tight Lines Professional

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    A standard tripod has a single screw for mounting a camera and will not fit an iphone. You will need to buy an adapter. I have something like this.

    [​IMG]

    You can get one for under $10 anywhere including amazon.

    Harry
     
  29. Egoista

    Egoista Professional

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    go for it
    ,,,,
     
  30. tennisplayer_85

    tennisplayer_85 New User

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    You can record from any view, but you need to have the server + the landing location of the ball in your video. Easiest way to do this is to record from were the opponent would be standing.
    You can press the INFO button in the recorder view of the app, here you can find detailed instructions on how to record.

    A tripod is very handy, great suggestion Harry!

    Soon ServeSpeed V3 will be there :)!
     
  31. Bdarb

    Bdarb Hall of Fame

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    I'd like to get clocked. Club pro said I was getting up around 110 last night. End unverified humble brag. Good enough for me though :)
     
  32. LeeD

    LeeD Bionic Poster

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    Most everyone should know if they have a fast serve, at their levels, anyways.
    If yours if the fastest of your peers, it's moving.
    If most of your peers have faster serves, then your serves are lacking in speed.
    If your serve speeds do justice at higher levels than yours, you have a good serve.
     
  33. PhrygianDominant

    PhrygianDominant Hall of Fame

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    I would like to know what the most accurate android service speed app is. Apparently this one is not available.
     
  34. cartel

    cartel Rookie

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    how far away is v3?

    can it be demo'd for a certain # of days ?

    and do you need a 4s or is the 4 ok to use?
     
  35. MF878

    MF878 New User

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    This app has been great so far. My first serve is consistently clocking in at over 100mph, so this is either the perfect app for 4.0 GOATs, or I'm a better server than I thought I was. A very helpful confidence boost, either way.
     
  36. LeeD

    LeeD Bionic Poster

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    But you fail in answering the question....is YOUR serve amongst the fastest of your peers, and is it amongs the fastest of better players than YOU?
    At around 105 mph, mine is by far the fastest of an 4.0 I've seen, and easily amongst the fastest in 4.5 and even 5.0, but there, lots of guys don't go for fast serves, they just spin it in high to the backhand side.
     
  37. SuperDuy

    SuperDuy Hall of Fame

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    What would you say this one I hit is at? I think slice at around 90mph maybe.


    http://www.youtube.com/watch?v=qCUsXpnb-AY
     
  38. Dimcorner

    Dimcorner Professional

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    I haven't tried this app but the online calculator seems about right. With the app I calculated 100-108. On a tournament with radar gun they got me at 112. Personally I don't think it's 112 but definitely over 100.

    I don't think anyone in my league at my level can serve this hard with some consistency. I get A LOT of free points with the serve.
    Yes it's possible for 3.0 to hit somewhat consistent serve (about 60%) at that speed, but I think I'm an exception. Years and years of badminton overheads will get you a leg up on serves :)
     
    Last edited: Jan 9, 2014
  39. thatguymattin

    thatguymattin Semi-Pro

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    According to the application, if you are 6'1'', then the serve was 105mph give or take.

    I just purchased this app, and I've been testing it with online videos.

    Can't wait to try it out in person!
     
  40. tennisplayer_85

    tennisplayer_85 New User

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    ServeSpeed V3

    Hi Y'all! Some where asking if V3 was out. Well it has been since the first of January! Was pretty busy and haven't been on the forum these days.

    I decided to make it FREE for some time! ;)
    So now is the time to get your copy!

    All I ask in return is ...'Please leave a review'... whatever you think it's worth, because this will help me a lot.

    Here you can check out V3:
    https://itunes.apple.com/app/servespeed/id581908085
     
  41. tennisplayer_85

    tennisplayer_85 New User

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    btw, I meant a review in the App Store after using it first :D!
     
  42. skygrinder45

    skygrinder45 New User

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    aaaah this looks so cool

    ...android port when
     
  43. Bdarb

    Bdarb Hall of Fame

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    Awesome! I'll dl and give it a try tonight.



    But if it says I serve any less than 120 I don't believe it :twisted: haha jk
     
  44. beernutz

    beernutz Hall of Fame

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    I just installed it on my Ipad 2 and plan to use it today at a tennis tournament being held at my club, assuming it stops raining. The interface at least looks very nice and is easy to understand and use.

    In the top left part of the screen it says 30 FPS. Is that because of a limitation of the Ipad 2's video capabilities?

    If it works well today I'll definitely fork over the $3 for a paid version.
     
  45. beernutz

    beernutz Hall of Fame

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    Well my testing of the app at the tournament determined that the app is very easy to use but also that the Ipad 2's camera sucks, at least for this purpose. First it is pretty hard to find a spot where that camera can capture both the server and the initial ball contact point. Also the camera will only capture 30 fps so it is a little difficult marking the exact frame where contact with the court happens. Contact with the racquet is easy to mark. Also you have to guess at the height of the server if you don't know it. I was able to measure a couple of serves and the estimates seemed right based on what I was seeing.

    I did another verification test today which supported the accuracy of the app.

    I found this video of a tennis radar gun on YouTube http://youtu.be/x_KCra2I16s
    I believe that radar is pretty accurate based on reviews I have read.

    So I played the video and filmed it with my Canon PowerShot SX260 HS camera at 120 FPS. I used the IPad camera connection SD card reader to move that video to my Ipad and used an app called ReelDirector to convert and export it to a format that could be saved in the Ipad Camera Roll.

    From there I started ServeSpeed and opened the video and went through the steps for the 93 mph serve. I had to estimate the height of the server at 6 feet and it was hard to see exactly where he was standing but it looked close to the back center mark. Anyway, ServeSpeed estimated it at 23 mph, which since I was using 120 fps I multiplied by 4 to get 92 mph. That is pretty darn close to the 93 measured by the radar so I'm a believer and the difference is probably rounding. I would suggest as a new feature of the app that when you enter your own video, you are able to enter the fps so the app can use that in its calculation of speed.
     
    Last edited: Mar 29, 2014
  46. gplracer

    gplracer Professional

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    I am out of shape. I got 97mph. Too much driving my kids to tennis tournaments. :)
     
  47. bullet1020

    bullet1020 New User

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    So basically the measuring of speed stops at the moment of impact on the service ground? And the measuring starts the moment the ball hit the racket?
     
  48. gplracer

    gplracer Professional

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    I measured my 11 year old and it said 92mph. Could this be correct? I know his serve is getting bigger but I do not think it is that big.
     
  49. BMcFarlan

    BMcFarlan New User

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    Just downloaded it. I'm excited to try it. The only reviewer stated that his serve is 119, so I'm a bit skeptical but hell it's free so worth a shot!

    Thanks for putting it out there!
     

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