Speed of serve estimation

Discussion in 'Tennis Tips/Instruction' started by jussumman, Nov 1, 2013.

  1. LeeD

    LeeD Bionic Poster

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    Still pic doesn't show whether the ball is heading down, bouncing up, or at the ground level.
    Look at the VIDEO of those serves, and by looking at the arc of the ball, and the bounce coming off, you might MIGHT change your mind.
    One still pic doesn't mean a thing, unless you can see the ball is squashed down from the impact.
     
  2. LeeD

    LeeD Bionic Poster

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    Oh, Suresh...:???:
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  3. TimeSpiral

    TimeSpiral Professional

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    [​IMG]

    Correct, that a pic isn't enough--but I didn't just send you a pic. I sent you a pic and information in the form of words.

    I analyzed the video and could find no evidence that the ball was long. I determined the frame of the video that represented the bounce phase, and sent it with my post. Alves testimony suggests that it was good.

    Merely "watching" a youtube video is not sufficient to determine whether the ball was out (and if you're not certain, then the ball is good, right?), especially when it appears to be a rather close shot. Similarly, a youtube video is not enough to say the ball was good either, on it's own, but since we have an eye witness, the burden of proof is on the person calling the ball out.
     
  4. LeeD

    LeeD Bionic Poster

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    :)
    Actually, maybe we should think this thru.....
    If indeed, the serve was good, the bounce would be higher.
    If the serve was long, wouldn't the bounce at the backwall be....lower?
    Am I giving credit where it isn't due?
     
  5. TimeSpiral

    TimeSpiral Professional

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    Nah, you're just a stubborn old man. Can't blame you for that!

    Determining the speed of your serve based on where it hits the backstop is pointless--too many variables. Just buy a freaking radar gun so you can know your "number."

    The only time knowing your serve speed matters is if you're actively trying to increase your serve speed. That's it. In a match, it doesn't mean anything. From an improvement perspective: you'd be better off paying someone to sit on the sidelines and log the match stats on a nifty phone app, or dropping two bills on a backstop mounting camera and filming your matches.
     
  6. LeeD

    LeeD Bionic Poster

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    Not sure a radar gun really accurately depicts a change of speed of say....,7 mph. Too many variables working there.
    Actually, I'm not sure any artifical measurement, taken by an amateur, can really tell us the true service speed. OTOH, the true speed might not be important.
    The effectiveness might be key.
     
  7. Avles

    Avles Hall of Fame

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    Is this some sort of Zen koan? I am having a hard time comprehending it.

    Awesome that this thread has become a debate about my crappy serve. I need to post more video!
     
  8. LeeD

    LeeD Bionic Poster

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    That long or short, high or low bounce thing...
    It's a point of diminishing returns.
    At really slow serve speeds, a deeper hit ball might bounce higher at the backwall.
    We still have to limit this within somewhat service limitations.
    At around 100mph, I find my shortest serves bounce the highest, because the angle of flight is more downwards, creating a sharper rebound angle, resulting in a higher bounce at the backwall.
    Deeper serves, and long serves, the ball tends to skid some, resulting in a LOWER bounce. Longer target, lower incidence of angle.
     
  9. TimeSpiral

    TimeSpiral Professional

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    A radar gun is the answer.

    Get your dataset large enough, index your progress, and you have a meaningful serve speed metric.
     
  10. LeeD

    LeeD Bionic Poster

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    My old mechanical drawing arch rival became a CHP officer in 1971. He is now in the office full time, and I ran into a mutual friend last week.
    Friend is a motor officer (bikes) and maintains that while the radar is accurate, it's accuracy is only + or - 7%.
    This, after the CHP has been using radars for 40 years.
     
  11. TimeSpiral

    TimeSpiral Professional

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    Sorry, man, but this data is easy to find and verify.

    Radar guns used by law enforcement are typically +/- 1 MPH margin of error. Civilian radar guns are usually within that specification also, although probably not calibrated as often (or ever). That doesn't mean you're going to be within 1 MPH accuracy every time when measuring your serve speed, because operator skill, and other conditions might affect the reading.

    This gun right here would be perfect for anyone looking to rate their serve speed. It even has a top rated comment by a long-time law enforcement officer who specifically tested it against his radar gun.
     
  12. LeeD

    LeeD Bionic Poster

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    Ah no.
    This CHP officer was near his bike, was ON duty, and we happenned to shoot the breeze due to stalled traffic in our direction, and recognition of each other.
     
  13. TimeSpiral

    TimeSpiral Professional

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    Lulz. Gotta love the LeeD!

    Anecdotes vs. data, a classic struggle, one I fight far too often ... not worth it here.

    The takeaway, guys:

    LeeD spoke to a guy one day that said radar guns have a margin of error of +/- 7%. Or, you can read the manufacturer and calibration specifications of the radar you want.
     
  14. LeeD

    LeeD Bionic Poster

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    Also, a bud of mine, from surfing and windsurfing, says that if a weatherman/person on TV get's it 48% correct, he/she/it wins the award for most accurate!
     
  15. LeeD

    LeeD Bionic Poster

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    Data can be construed or misconstrued any way the observer wants, it can be adjusted, compensated or just ignored, parts, the whole, or tiny segments.
     
  16. r2473

    r2473 Legend

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    It's the ideal tool for tracking tennis serves from 10-110 MPH.

    Top speed of 110 MPH? I can't see how this would have any value for TT posters :confused:
     
  17. TimeSpiral

    TimeSpiral Professional

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    That's true ... 4.0's should be serving 120+ MPH down the T pretty regularly. Please excuse me.

    In all seriousness, if you're serving faster than 110 then you don't really need this radar gun. You're doing just fine.
     
  18. shindemac

    shindemac Hall of Fame

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    There are lots of other cues you can use to determine your relative improvement. But having a radar gun takes the guesswork out of it. And having a serve speed app doesn't cut it. You need real time feedback on your serve so you know how to make corrections. If you can have a good coach correct your mistakes, that would be the best but most expensive option.

    I didn't want to get a radar gun that tops out at 110. That's just too low.
     
  19. rufus_smith

    rufus_smith Professional

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    It got this negative review on Amazon, I tend to believe the review because the other low cost radar device tennis players tend to buy (i have one, speed trac) also seems to under-estimate the serve speed by 10% or more too.

    2.0 out of 5 stars Struggles with smaller objects April 21, 2008
    By Ohio Baseball
    I bought this to measure two things basically: tennis and baseball velocity. After testing the gun at first just on some cars, I was excited because it was extremely accurate. However, once I went to measure baseball pitching velocity and tennis, it was consistently 15-20 mph slow. The baseball pitcher was throwing in the mid to upper 80s, and has been verified by a JUGS gun, and he was topping out on this gun at 73. I wanted this to work so badly because it is a great price, but I believe I will have to return it because it has not been accurate for me on what I wanted it for.
     
  20. oest10

    oest10 Semi-Pro

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    You must be nearly blind and fully deaf! Respect for playing tennis with that going against you :eek:
     
  21. TimeSpiral

    TimeSpiral Professional

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    Good point, Rufus! I don't have one because frankly, I don't really care what my serve speed is enough to buy one.
     
  22. r2473

    r2473 Legend

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    Nearly every time I play a new opponent (tournament, league, or just club play), they will almost without fail ask me if I've ever had my serve speed measured on the first changeover (I've never had it tested). Most guys guess my serve speed at around 120. I've had people say as fast as 130. I know its nowhere near 120, but I can tell these guys really want to go home and tell their buddies that they "faced a XXX MPH serve", so they toss out high numbers.

    Serve speed is such a funny topic and something people seem so interested in.
     
  23. psv255

    psv255 Professional

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    ^ Seems like it's another form of spitting contest
    Could also be a stage of any tennis player's development, wonder if the pro radars have anything to do w/ it...
     
    Last edited: Nov 14, 2013
  24. Topspin Shot

    Topspin Shot Legend

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    At high levels, serve speed isn't very straightforward because players put a lot of spin on first and second serves, which slows down ball speed a lot but provides heavy kick and margin for error so the serve can be bent to various targets. Many players I know, including myself have clocked over 120, but this number means nothing because the serve is dead flat and doesn't go in enough for match play. My match first serves hover around 100 because of the spin. Which makes a pro's 120 mph first serve with spin all the more impressive.
     
  25. Ballinbob

    Ballinbob Hall of Fame

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    Agree with this 100%. Most of the DI players I see playing here hit first serves around 100-110 tops but with a lot of spin. I saw a blue-chip recruit play who was like 5'7-5'8 who had a wicked kick serve that was only like 75-80mph tops...So speed doesn't necessarily mean effective

    The only players I even see attempt to hit a flat serve are around 6'4. Not many can hit it with it any consistency
     
  26. Avles

    Avles Hall of Fame

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    Well, for those of us who were hitting 55 mph pancakes not all that long ago, clocking speed is one semi-objective way to measure progress.

    But yeah, realistically, being able to consistently place a slower, spinny serve out wide, and then send it up the T every so often to keep opponents from cheating, would be preferable to hitting a "fast" but eminently blockable serve with suspect placement.
     
  27. winstonlim8

    winstonlim8 Semi-Pro

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    My apologies. I didn't see this thread when I started the other one.
     
  28. jussumman

    jussumman Semi-Pro

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    I only made this thread about speed estimation of serve because I got excited about hitting a serve not totally weak for once. I understand that the spin, the location of serve and change up dynamics are as important or more important than speed.
     
  29. Topspin Shot

    Topspin Shot Legend

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    That too, but what I'm emphasizing is the energy the incoming ball has. A 100 mph topslice can have the same energy as a 125 mph flat serve, and that energy will be released after the bounce. So someone used to returning a 100 mph flat serve may get his racket on the 100 mph topslice, but his stroke will not be able to handle the heaviness of the ball, and he will spray his return. The bend in the air and kick after the bounce in which the ball retains more of its velocity post bounce will also wreck the returner's ability to return the serve. This is even if the ball is not placed well, and the returner knows what's coming.
     
  30. LeeD

    LeeD Bionic Poster

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    I think we know a 100mph top/slice is more effective than a 100 flat serve, placed at the same spot.
    Pros hit into the mid 120+ range, on flat serves, and up to 155.
    Most of us hit flat serves at 100, and spin serves much slower. Can we agree there?
    But speed IS very important, as is placement, consistentcy, replication, depth, and timing.
    Hard to judge and catagorize most of those criteria, except speed of serve.
     
  31. Mrnoital

    Mrnoital Banned

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    :confused: It's just as straight froward whether you put spin on it or not and it doesn't matter who is serving.
     
  32. Mrnoital

    Mrnoital Banned

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    There are like 3 people in history to ever serve 155.
     
  33. LeeD

    LeeD Bionic Poster

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    PRO's. If ONE does it, it counts.
    Dr.Ivo.
    Milos.
    Roddick.
    Groth.
     
  34. Oz_Rocket

    Oz_Rocket Semi-Pro

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    Agree 100%. Last weekend I was spectating at a tournament and finally had my serve checked by radar. Went 186kph (115mph) but that was using a light kid's racquet and green dot low compression ball. So with my normal racquet and adult ball I could get it up around 200kph. Back in my 20s when I was fairly fit that was more like 210kmh and they'd go in enough but these days in my 40s maybe one in every 5 would go in and being flat a decent pro could hammer it back return after return.

    P.S. There was a current top 200 player at the tournament with a 220-230kmh serve that when flat and placed in the corners was an ace nearly every time. But he could throttle back to "just" 190-200 with plenty of work on the ball and those were almost unplayable.
     
  35. LeeD

    LeeD Bionic Poster

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    Any serve, at any level, will come back if you don't place it within 7" of the sidelnes, center hash, or into the hip pocket.
    At 140+, it just comes back less often.
     
  36. Mrnoital

    Mrnoital Banned

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    They're not more important than speed. In fact none of those other factors will mean diddle without some speed. Speed is a huge part of the equation. Don't be fooled into thinking you don't need pace.
     
  37. Chas Tennis

    Chas Tennis Hall of Fame

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  38. jussumman

    jussumman Semi-Pro

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    "Donald Young 1st Serve Avg. 101.9 2nd Serve Avg. 80.6"

    Aren't these recreational tennis stats (4.0-4.5ish). Only if you're a lefty can you get away with this and still manage to be an ATP pro on tour?

    Edit: Nevermind, I think I got my answer.. TopSpin -"So when you see a pro's average first serve speed hovering in the 100s or 110s, you know he's putting a ton of spin on the ball."
     
    Last edited: Nov 20, 2013
  39. Chas Tennis

    Chas Tennis Hall of Fame

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    It's informative to search for some stats and see what they are.

    I recorded a few from a Federer vs Wawrinka match. Probably not typical because Federer had a back injury issue.

    Federer (back injury issue) - 14 good serves but don't know 1st or 2nd, in increasing order
    77
    86
    88
    91
    102
    111
    112
    114
    115
    118
    119
    120
    123
    124
    Overall avg. 107 MPH

    Wawrinka - 18 good serves, don't know if 1st or 2nd serve
    84
    89
    91
    91
    95
    95
    96
    97
    97
    100
    103
    107
    107
    109
    118
    120
    130
    131
    Overall avg. 103 MPH
     
    Last edited: Nov 20, 2013
  40. tennis_ocd

    tennis_ocd Hall of Fame

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    If anyone here could truly serve at 140+ it ain't coming back. And I don't care where you land it.
     
  41. TennisCJC

    TennisCJC Legend

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    Chas Tennis: you can look at Wimby stats and see Federer is around 117 mph in his prime for 1st serve average. I think around 95 mph avg for 2nd serves. When he was winning 5 in row, this was pretty much automatic. Some of the bigger servers like Raonic and Jersey avg in the 120-125 range.

    I played a D III player who was clocked at school and his 1st serve was a heavy spin serve around 93 mph. This kid actually played a season of 4.0 usta with us because his dad was on the team. To give a comparison, his mid 90s heavy spin serve was near the top of the league in pace and spin. Basically, of all the teams we saw, I don't think anyone could serve faster on average or had heavier spin. Someone might get the odd 110 mph flat serve but their average serve speed was either significantly lower than the kids or there percentage was in the 15-20% range.
     
  42. Chas Tennis

    Chas Tennis Hall of Fame

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    Tennisspeed has a blog. He did quite a few measurements a few years ago and the average numbers were less than I had expected. So far that's one of the best assemblies of creditable measurements that I've seem. I believe that the DIII player you describe probably has a heavier spin serve.

    You can take a video using a smartphone from the side and get a pretty good measurement of the pace if the phone can be verified as at 30 fps. The average tennis racket is about 27" in length. Roughly, if the ball travels 2 tennis racket lengths, 54", between frames at 30 fps, that's 92 MPH. (100 MPH is 58.7" between frames).
     
  43. LeeD

    LeeD Bionic Poster

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    C'mon you fools.....
    AVERAGE takes into account safe wide slice serves, some twist serves, some faster top/slice serves, and a FEW flat heaters.
     
  44. LeeD

    LeeD Bionic Poster

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    And you fools....
    A Ferrari might have a top speed of 197, but it's AVERAGE speed when you see it is about 63 mph.
     

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