
What It’s Like to Face a 150 M.P.H. Tennis Serve [video] - geoka9
http://www.nytimes.com/interactive/2015/07/10/sports/tennis/facing-a-150-mph-tennis-serve.html
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minionslave
This is pretty interesting. It shows how much specialized a human can get at
doing something. It truly is the closest thing we've got to superheroes.

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rawnlq
There was a post a month ago on how to write an app to measure serve speed
using computer vision:

[https://news.ycombinator.com/item?id=9611298](https://news.ycombinator.com/item?id=9611298)

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tdicola
That's great! What's changed in the last 30 years that serves are so much
faster? Racket design? Balls? How we measure the serve?

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geoka9
Several factors:

Rackets - they got more forgiving and powerful. I think even Mac now serves
faster with a modern graphite racket than he did 30 years ago with a wooden
one.

Strings - with the invention of polyester strings which snap back after
"gripping" the ball during the stroke, the amount of top spin applied to the
ball has gone through the roof. That means players can string their rackets at
lower tensions, allowing even more power on their strokes (including the
serve).

Overall physical fitness and training standards of pro tennis players -
today's top tennis players are simply better athletes.

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Encosia
Poly definitely changed the game in many ways, but not as much when it comes
to _fast_ serves. Even strung in the 40lb range, poly strings generate much
less power than gut. You'll find that most of the big servers still use gut in
the crosses (and they'd probably use all gut if they could just hit serves and
no groundstrokes).

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geoka9
The idea is that because of the poly in the mains you can generally string
your racket at a lower tension (including the gut in the crosses), which
increases power (without the gripping poly you couldn't use low tensions
because the ball would fly on you on anything but the first serve).

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Encosia
The advantage of poly isn't that it grips, but that it's elastic enough to
deform and snap back quickly. The old idea of string having 'bite' has been
mostly disproven with the advent of high speed video to show what's really
happening in the fraction of a second during impact. Those geometric extrusion
strings are more marketing than anything else (and shred your stringer's
fingers).

I play with full poly at 48#, but have experimented with gut hybrids and full
gut at times. Even comparing 48# poly to 60# gut, the gut is like a rocket
launcher compared to the poly. The amount of power it generates, at any
tension, is unreal. You can hit huge flat serves with it, but the lack of spin
isn't worth the extra pace.

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geoka9
> The advantage of poly isn't that it grips, but that it's elastic enough to
> deform and snap back quickly.

Sure, I should've put "gripping" in quotes - what I meant is the top spin
potential, not the actual physics behind it.

> Even comparing 48# poly to 60# gut, the gut is like a rocket launcher
> compared to the poly.

How about 60# full gut vs 50# hybrid (gut in the crosses)? Would the former
still be a lot more powerful than the latter?

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Encosia
> How about 60# full gut vs 50# hybrid (gut in the crosses)? Would the former
> still be a lot more powerful than the latter?

The hybrid setups I tested were usually in the ballpark of 46-48# poly mains
with 50-52# gut crosses. My experience was that the hybrid setups were
(obviously) more powerful than full poly, but still very noticeably less
powerful than full gut at any tension. Without poly's spin/control, the full
gut setups were a big disadvantage from the baseline, but I could hit some
amazing (for me) first serves.

I didn't experiment too much though because I was breaking every gut hybrid I
tried in a few hours, which got expensive quick.

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oluckyman
My nephew played in a minor tournament that Sam Groth won a couple of years
ago. He said Groth did a second serve kicker that bounced over his opponent
and continued over the back fence.

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eweise
I just watched 7 days in hell where he serves 174 mph. Just incredible!

