
Smash: The game changing tennis wearable - evjan
https://www.kickstarter.com/projects/1123712033/smash-the-game-changing-tennis-wearable
======
gorkemyurt
Varsity tennis player here. I have been using my fitbit bracelet for a couple
months now, I have to admit that the device is inaccurate. I am pretty sure it
undercounts running distance and number of steps. We are talking about big
wide steps that happens in a consistent manner. A players movement on court is
much more complicated. Such a bracket for tennis players needs to be much more
accurate than my fitbit flexband to be useful. A good tennis player never
takes a wide big step, almost all the movements on court are quick small
steps. Unlike running, a player changes direction all the time. It would be
really cool if the bracelet can give the player data about his footwork but I
think the emphasis on this particular product is on the actual technique. Man
its not easy. Sure there might some easy wins in the beginning, like counting
how many forehands or backhand a player hits or things like how hard have you
been hitting the ball. But I think its extremely hard to dig more into it.
“How much spin are you giving”, “Are you hitting the ball late or early", “How
fast can you recover when you hit the ball(combine it with footwork)”, “How
high is the ball when you hit it” “Are you bending your wrist too much, or is
you elbow really close to your body”. “Are you hitting the ball just with your
arm or your shoulder and your waist follows through with the movement" These
would be the questions that an intermediate tennis player would be interested
in. However I am afraid these all happen in a fraction of a second and I
really doubt a bracelet is accurate enough to give the player insightful data.
Sure its a really cool device (still not useful) for people starting to learn
or maybe little kids competing against each other, but there is a long way
until a serious tennis player can benefit from this. I am a software engineer
myself and it was always my dream to do build something about tennis. So go
for it man..

~~~
tonylemesmer
Have you seen this? Babolat racket has the sensors built in:
[http://en.babolatplay.com/features](http://en.babolatplay.com/features).
Tennis players might prefer this to wearing a bracelet on their playing arm.

~~~
fthiess
My wife plays a lot of tennis, and I bought the Babolat racket for her for
Christmas. Great idea, but it's implementation is awful, primarily because the
software is complete crap. We're using it with Mac/Android, so maybe the
Windows/iPhone version is better, but the software problems are pervasive and
make it pretty much unusable. We called Babolat about it and they were
completely unhelpful--their support staff didn't seem to be trained to deal
with anything other than physical rackets. This is all fixable--but fixing it
would require a company that's great at building rackets to learn how to build
great software... unlikely, and there's no sign that it's going to happen. A
device like the Smash (or other separately wearable tech) is more likely to do
the software right.

Beyond Babolat's bugs, there's a deeper issue: it shows you a lot of data...
but it's not clear that that data is actually useful. So 24% of your hits are
on the upper quadrant of the racket... so what? Is that good or bad? If bad,
what advice would a coach give you to improve? This drove my wife crazy: when
we occasionally got her racket to sync properly she was rewarded with a flood
of numbers that meant nothing to her. Smash's video says it will "make
recommendations like a coach would"\--which is what you actually want, so
hopefully they are able to deliver on that promise.

------
callmeed
I don't tennis, but it looks pretty cool.

At the risk of thread hijacking, I have a broader question. My assumption is
that most wearable bracelets have the same tech/sensors inside and the
difference is in how your software interprets said sensor signals. _So why
doesn 't someone create an open bracelet that people can hack and customize
for any sports/fitness application?_

I mean, I would have loved something like this for baseball back in the day
(both for pitching and hitting). There are wearables for golf too[0].

So, why not just a generic wearable + SDK/app store?

[0] [http://mashable.com/2014/05/22/zepp-golf-sensor-
review/](http://mashable.com/2014/05/22/zepp-golf-sensor-review/)

~~~
icegreentea
Oh man, you have no idea how much this gnaws at me. Especially with the Myo.

So, for a bit of background, the Myo has 6 (or was it 9?) EMG channels, and at
least a 6 axis IMU (I think it might have magnetometer as well). The developer
API they plan on releasing will only give you the post processed signal + the
raw IMU signal - that is to say, they'll tell you the current affinity to each
of the pre-programmed gestures (~6 or so) that Thalmic has set up. There is no
way to normally get access to the EMG data.

They will however give you units with 'special firmware' if you sign up for
their researcher partnership program which costs $10k+ the last time I talked
to them (this winter). Needless to say, this is clearly aimed at university
research labs.

I can't really say just how frustrating this is, as someone just leaving
undergrad, and with a passion for sport and science/engineering. The worst
part is just how understandable it is.

Nearly all the players in this field are startups of some sort. Their #1 goal
is to get stable positive cash flow out of some niche market. As a hardware
startup, they have significant costs to overcome. There just is no incentive
for them to split off some effort to try to capture this type of open
system/market.

But seriously, I crave an open hardware platform for this. But at the same
time, it's obvious that the costs are non-trivial. The 'science' part of the
payload isn't even hard. IMU + microprocessor + bluetooth. The hard part is
hardware packaging, getting it into a form factor that has enough battery
life, will stay in position on the body, will not adversely bother the user,
or modify their movement. All of these issues are non-trivial and have to be
solved for hardware release.

Seriously, I wish I just had a pile of cash, and a couple years to ticker.
_sigh_

~~~
srlake
I'm one of the co-founders at Thalmic (Myo).

We get the request for raw muscle data quite often, and are trying to find a
way to handle it better in the future. The reason we don't provide it now
actually has nothing to do with money (we do have a small number of research
groups that pay for this, engineering support, and other services, but it
represents a tiny fraction of a percent of revenue).

The reason is actually two-fold:

1\. User Experience - Unfortunately you're probably the exception, in that it
sounds like you may be able to build a great experience using the raw data.
The reality we've found is that it requires a deep machine learning and
statistical analysis background to do much useful with the data, considering
the need to account for a wide variety of variations in data intra and inter
person. What we're trying to prevent is developers attempting to create
"custom" gestures improperly (e.g. if (myo.sensor1 > 67% && myo.sensor2 >
30%){output = Rock_On}), which will not work reliably on the population, in
different orientations, etc., then the user has a bad experience, and blames
the device hardware.

2\. Battery Life - Streaming raw data uses much much more power than when we
process the data on the device, and recognize gestures directly on-board.

We are considering options to provide this data in some way, as there are
certainly good uses in some applications, such as Tennis analysis.

You could quite easily do everything the Smash device does, plus additional
information on grip strength, using a Myo armband. It's all about the
software!

~~~
icegreentea
It's great to hear that. I'm sure you've heard this already, but there are
non-trivial amounts of part-time researchers who are salivating over your
tech, principally as a tool for scientific exploration, or just tickering.
These aren't so much people coming out a developer background, but those
coming from a research background, people who can totally understand and
stomach difficulties associated with EMG.

Basically, I believe there to be a great deal of people who are in similar
situations to your current research group partners in technical aptitude and
expectations, but differ in their financial resources - which is why your
product in particular is so attractive in the first place.

I really look forward to seeing how this develops.

------
withdavidli
Tennis player here..ummm... As legohead brought up, there are other things to
consider like stance. I can see how this thing can be accurate if we had four
of them (ankles and wrists). This can show show most of the moving parts, can
replay how the body moves (likely hand location and elbow extention), open vs
close stance, how fast were moving from point A to point B.

I don't know how they're measuring ball rotation, purely by the angle of an
upward swing? Don't know if this is accurate. Is this an area it would suggest
for improvement? RPM has a large range up to ~5,000rpm (Nadal). What would it
even cosider optimal to make a shot?

Don't know how the device would know if a ball would land in or not, is this
even a major area of concern for the device? Pretty strokes are one thing, but
unless the ball lands in, it doesn't matter.

Depending on how accurate this device is (probably would need more than one
bracelet per person), it can be used for any sports. More importantly, there's
a possiblity to measure bad form and increased pressure on certain joints to
prevent injuries.

Looking forward to see technologies brings forth in the coming years!

------
skbohra123
Shot Stats[0] is another Tennis related kickstarter currently going on.

[0] [https://www.kickstarter.com/projects/laviesak/shot-stats-
cha...](https://www.kickstarter.com/projects/laviesak/shot-stats-challenger-
make-your-tennis-racket-smar)

~~~
AjithAntony
Attaching to the racquet does seem like a better idea. I'd be more inclined to
believe it could do things like measure the speed and angle of the head
better, than at the wrist.

------
robcrowder
Hi, just thought I'd jump on here and answer a few questions. Thanks all for
the interest!

You're right in saying the components are pretty ubiquitous, the key part is
the algorithms which interpret the data. They would need developing for each
sport or particular movement, plus a UI to replay back the insights in a user
friendly way. We spent months on this with Smash, it was the real focus of the
early work, and will continue to be so. Some kind of platform that allows this
to be done easily feels like a great next step...got me thinking :)

Rob

~~~
fma
I find your product interesting and just did some brief research. From a
tennis perspective, what would differentiate your product from Zepp?
([http://www.zepp.com/tennis/](http://www.zepp.com/tennis/))...besides the
fact that Zepp is on the racquet while Smash is worn on the wrist. Since Zepp
is a mature product and can be purchased from the store or online
already...have you had a chance to try it and compare it to your Smash
prototypes? Thanks.

~~~
robcrowder
I have tried it yes. Our difference is the focus on technique and providing
insight. I think Zepp just released a feature on serving which looks pretty
cool, I would imagine they're heading down the same path. The key is the
experience, it's got to be simple and useful

------
neilsharma
Former tennis player here, and builder of a similar device for weightlifting
form. Unlike a lot of other wearable kickstarter projects, I think most of the
technological claims here are legit. That said, I'm not sure if it does enough
to be useful for an avid tennis player. To improve my game, I would like to
see:

1) Swing form correction

2) The angle of the racket relative to an incoming ball (to predict air or
ground balls)

3) Stance information.

Form correction would require position data during the entire swing. Position
information is two integrals away from acceleration data collected from the
sensors, so it's far too noisy to determine that well enough.

I don't know how would you would measure stance with a bracelet, and I'd
imagine that racket angle is unreliable.

I also question the ball speed measurement for a similar reason to form
correction. I'd imagine a possibly effective way to measure speed would be to
correlate acceleration data with externally measured velocity data collected
in real-life trials. That said, unless you're competing at an advanced level,
speed is a vanity metric so I don't care if its a ballpark estimate.

Video recording, however inconvenient it may be, addresses all these well. I'd
rather see a camera added to tennis courts to record your performance, but
that's far less sexy of a product to build.

That said, the bracelet looks sexy and the goal of personal training sure
beats the hell out of fitbit/fuel/jawbone's capabilities.

------
_s
Pair wearable tech with future iterations of Tango/Kinect and you're onto
something even bigger.

Tennis for example -

Think about a computer picking up flaws in technique that the human eye would
miss; a coach would only be looking at your leg work or arms or upper body but
a computer will tell you a multitude of things - wider stance, shoulder's
turned to the right a bit more, less follow through, more weight on your front
foot etc etc - then imagine it coming straight to your ear every time you
place a shot. Pair it up with a ball tossing machine and you've got a coach
that knows precisely where you're going wrong, how to fix it and giving you
the best possible advice and opportunities to do so (forehand shoddy? that's
all your getting until it improves etc).

The next decade has just gotten so much more exciting. I'd love to find
someone somewhere working on a "complete" system, not separate bits of it - we
already have video analysis, wearables, weight sensors (wii fit?), someone
just has to slap them all together.

Side question - aren't there golf swing analysis places already which use a
myriad of tech to give feedback?

~~~
skiltz
This is exactly what we are working on at CoachSeek. We are creating a
complete management system for coaches, which will in time integrate with a
number of wearables to give sports coaches a central place to manage all their
client data. [http://www.coachseek.com](http://www.coachseek.com)

------
rickdale
I would look into this more. I was watching the French Open just yesterday and
I heard Darren Cahill say that top juniors now a days have the technology so
that when they walk off the court it will tell them what strategy worked what
percentage of the time and what they should have been doing more. Pretty
interesting comment, although they never did show an example of it I totally
believe it. Babolat[0] pure drive meets Sony[1] racket sensor.

The only project I ever built with an Arduino is a wristband with a piezo
sensor and it counts the number of balls I hit while was practicing. I thought
about expanding it more, but that was the only data point I was really
interested in.

0\. [http://www.tennis-
warehouse.com/Babolat_PLAY_Pure_Drive/desc...](http://www.tennis-
warehouse.com/Babolat_PLAY_Pure_Drive/descpageRCBAB-
BPLYPD.html?gclid=CNHb1Yruy74CFa1cMgodRm0ATw)

1\. [http://www.theverge.com/2014/1/20/5326558/sony-smart-
tennis-...](http://www.theverge.com/2014/1/20/5326558/sony-smart-tennis-
sensor-price-and-availability)

------
skierscott
This is a very interesting concept. A side-note: while receiving immediate
feedback is useful, a coach is still incredibly useful. They tell you _how_ to
improve the one stat and more importantly broader strategy (where to stand,
where to hit, etc).

I wonder what other sports this can be applied to. My guess is that swimming
is a prime candidate and maybe shotput/javelin or baseball pitching.

~~~
evjan
A few come to mind: boxing (incl thai boxing and MMA), golf, ice hockey,
bandy. So many swingin' sports!

~~~
damian2000
A smart boxing glove that can iteratively learn the required knock-out force
for different opponents?

------
Shrugs
I made a similar product (albeit a lot less refined) for a hackathon, using
the Pebble. It counted number and type of tennis shots, displayed useful HUD
data, and then let you see pretty graphs in a desktop webapp. Some problems I
ran into:

If you have acceleration, to get position, you have to integrate twice, which
means two unknown constants, really throwing off your data accuracy. To fix
this, the user would have to go back to a defined position (perhaps the tennis
'ready' position) frequently, but that isn't guaranteed or user friendly. They
could absolutely work around this with some refined heuristics, but I wasn't
able to get one working in the few hours I had.

The algorithms are the hard part. I was using naive machine learning
techniques to identify swings and such, and they were not nearly adequate; I
had many false positives. If they can get all of the stats they claim, I'll be
very impressed.

------
waylandsmithers
It seems that no one else has a problem with this, but I'm still not
completely sold on Kickstarter projects that essentially function as pre-order
mechanisms for products in development. Shouldn't this money be coming from
investors or lenders?

~~~
sp332
Yeah, Kickstarter is pretty clear that they're not aiming to be a pre-order
site. And there has been a lot of discussion about the fact that backers have
no real stake in the company, especially after Oculus got acquired by
Facebook.

------
deepGem
I am skeptical about this device becoming a game changer in tennis. I played
tennis for a while and what really helped me then was video analysis. While
data is helpful, it's not as helpful as video. If the wearable could depict my
form and technique from data, that'll be a game changer. For game improvement,
we don't lack knowledge. After playing any game for a while, we'll know our
limitations - but to tide over those limitations you need hours and hours of
practice along with a coach. During those rigorous practice hours, your mind
gives up and you just want to quit, but your coach won't let you do that :).

~~~
hershel
Playsight does this:

[http://www.usatoday.com/story/sports/tennis/2013/11/28/play-...](http://www.usatoday.com/story/sports/tennis/2013/11/28/play-
sight-smart-court-tennis-technology/3773869/)

------
legohead
As a tennis player I don't see how this is going to help me. At least the
video & description of the product don't explain it very well.

I've been teaching my daughter tennis, and the issues she has (and that I have
as an amateur) need very specific attention -- how you are holding the
racquet, follow through, feet position, anticipating ball placement..

The description says it gives "tips and advice" \- like what? Can it tell me I
need to rotate my grip 10 degrees? That my backhand starting swing position is
too high? That I am trying to hit the ball too soon or late? etc.

~~~
robcrowder
Thanks for the feedback, really appreciate it. I envisaged the player profile
being the place to set your grip, e.g semi western. It's a reference point
I've been using to develop the algorithm's. The device can help you with
follow through, point of impact, backswing. Footwork and movement is another
story and is kind of what I have in mind for phase 2, doing a bit of
investigation with iBeacons but line of sight is tricky

------
swanson
Interesting from a gadget standpoint - I wonder if any "regular" tennis
players will be interested. I am reminded of this very clever lean startup
experiment about a similar concept (though it was in the racquet, not a
wearable).

MVP experiment using a walkie-talkie to fake a "smart racquet":
[https://www.youtube.com/watch?v=2eJbu4EtHMk](https://www.youtube.com/watch?v=2eJbu4EtHMk)

Results of the experiment:
[https://www.youtube.com/watch?v=gZzYUW3-JHQ](https://www.youtube.com/watch?v=gZzYUW3-JHQ)

------
jonalmeida
What I don't understand yet, is what hardware on this band makes it different
from other wristbands (besides form factor)? If all the calculations are done
on the mobile app, and the wristband is just a data collector, why not
implement this app to integrate with existing bands?

We've seen so many wristbands (and now watches) releasing, it doesn't make
sense to have separate bands for separate tasks. We'll eventually have a
similar problem where every website has it's own app.

------
JoachimS
I was sort of expecting a responsive bracelet that would actively help you.
For example by vibrating more or less to help you swing properly (stay on the
correct path, buzz until complete follow through etc, buzz when you are at
correct spot in serve to help you time the ball etc etc).

This looks more like a good, smart application specific flight recorder. Very
cool, but not as game changing cool as I first thought it would be.

Keep it up though - it is a great game!

------
zohaibr
Isn't this the same thing - just as a bracelet.

[http://preorder.moov.cc/](http://preorder.moov.cc/)

Apart from the dedicated Tennis application.

~~~
bryans
This looks very well thought out and phenomenally useful for general fitness
alone, with the potential to handle all sorts of applications, including
tennis analysis. It's unfortunate that they're incredibly vague about what
"summer launch" means, considering summer is only a few weeks away.

It is also very unfortunate that Android compatibility will not exist for
another 4-6 months at the earliest. Focusing on a single mobile platform isn't
something that should still be happening these days, especially when Android's
market share dwarfs that of iOS. I look at the decision to focus on iOS in
2014 as a highly questionable business decision, at best.

------
hoopism
I'm a nerd and love data... so I am happy with the response to this question
being "because it's cool"... but is anyone actually reaping any reward beyond
the basic placebo effect by wearing any of these devices? It might make me
want to train more just to see the data... but is the data really helpful?

I wonder if we'll be looking at these devices like Nike Pumps in a few
years... all gimmick.

~~~
coldpie
Consistency is a major factor in pretty much any sport. It's difficult to
improve your performance if you don't have a consistent baseline from which to
diverge, just like how you change only a single variable when using the
scientific method. I know little about tennis mechanics, but I imagine a
hypothetical experiment could be something like "Do I get a lower bounce if I
put the angle the racket slightly later during the swing?" Being consistent is
the first step to being able to test that theory.

Gathering data during practice and play allows you to know if you're being
consistent, and if you're not, when those inconsistencies occur. Once you've
hammered out the inconsistencies, you can start to experiment and improve your
technique.

Weight lifters make meticulous notes about their workouts. Even amateur race
car drivers spend thousands of dollars on data logging equipment. Professional
sports players spend hours watching videos of themselves. At a high level,
it's all about data and analysis to provably improve technique.

~~~
hoopism
I am not questioning the value of data collection... I guess I am more
questioning the data quality and applications.

I suppose it's less relevant if we agree some data is better than none. I also
wonder about the relevance to the weekend warrior. Is this something that
really will improve their game? Or is it just a fun way to engage in a hobby?
Maybe it doesn't matter from a market viability standpoint.

~~~
saraid216
> I also wonder about the relevance to the weekend warrior. Is this something
> that really will improve their game?

Yes, if they're interested in improving it. For basically all the reasons
coldpie has already pointed out. It's true that you'd need to practice
specifically as well as play games--it's much harder to develop higher
consistency from the dynamic environment of a real game--but that's not
unusual.

------
ljf
I'm hoping that something like the Vidonn X5 (
[http://www.vidonn.com/en/](http://www.vidonn.com/en/) )gets open sourced -
it's $40 device, inc postage, and seems to have everything it needs to do most
of what I want... except the app is pretty poor.

If you could use this with your OWN apps then it would be a killer device.

------
argumentum
I quit working on this same idea about a year ago after concluding that the
resolution on (existing) 9-axis IMUs wasn't good enough for serious tennis
players.

Then again, maybe just being able to see your racquet head speed increase as
you improve your technique will be enough for a "quantum of utility" for
beginners.

Good luck to them!

------
inutard
This is a great idea! I've just pledged 140 AUD. I don't play tennis, but I do
play a lot of badminton.

My hope is that they'll eventually give software devs access to an API so that
I may refine their product to work for badminton.

~~~
amarcus
It looks like they are planning on doing so. From the Kickstarter page:

"We’re planning to open up an API to developers. There’s going to be a
truckload of data, and whilst we have our own visions of where Smash can go,
we wouldn’t want to restrict others from creating greatness. We're keen to
move Smash into more sports and create more insightful features for players."

------
nathan_f77
Really, really, really impressive design. But I think this is a really,
really, really small market, and I don't think there will be enough interest
to meet the fundraising goal. Hope to be proven wrong, though.

------
meric
I wonder if it's possible to build Smash for the Google Glass, to get
_instant_ feedback instead of looking at the app post-game. Actually, it is
possible, and I hope it happens soon.

------
rasz_pl
~$200 for wearable accel/gyro chip? You have got to be kidding me.

~~~
ballstothewalls
It is the price of a quality tennis racquet and comparable to running GPS
watches which perform a similar function (though with different hardware and a
different sport). Not to mention tennis is a pretty pricy sport. Frankly $200
sounds cheap to me.

------
deutronium
I'm curious if there are any computer based training tools for tennis that
make use of a high speed camera and do image processing to analyse your swing
etc.

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loceng
I love that logo.

