Tennis Racquets

Functional Tennis Saber Review

The new training tool from Functional Tennis. Is it just a gimmick or does it hit the sweet spot?

The Saber is a brand new tennis training tool from the guys over at Functional Tennis designed to help players hit the ball on the sweet area, increase their concentration and improve their contact point.

There are a few sweet spot training tools on the market, but this one is designed and weighted like a proper tennis racket, only with a mini head compared to your typical 100-square-inch racket.

I preordered mine, received one of their first batches to ship, and soon took it to the courts to test it out.

How does it play? Is it any good? Find out in this full Functional Tennis Saber review.

What is the Saber?

functional tennis saber on court


For cricket fans, there is a well-told story that the great Sir Donald Bradman used to practice batting with a stump instead of a cricket bat.

Nowadays, there are specialist training bats made where the blade of the bat has the edges trimmed down, so it is around two-thirds the width of a standard cricket bat.

The Functional Tennis Saber applies that same concept to tennis by reducing the racket head size from your typical 98-100 square inch racket to 37 square inches.

This helps improve your hand-eye coordination, and the smaller surface area is designed to encourage cleaner hitting, meaning that by the time you come to use your full-size racket, finding the sweet zone will be easy.

Saber Specification

saber weight
  • Head Size: 37 sq in
  • Weight (Unstrung): 300g
  • Weight (Strung:) 312g (mine was 309g)
  • String Pattern: 12×12
  • Swing Weight: 270
  • Beam size: 22mm straight beam
  • Grip size: L2 (4 1/4)
  • Strung: Yes
  • Material: Mixed composites of Carbon Fibre and Fibre Glass

First Impressions

saber sweet spot

The Saber arrives packed in a long slimline box that almost looks like it could fit through a letter box.

It comes with a soft, draw-string racket sack which is a nice touch.

After unwrapping it and doing a few shadow swings, I was excited to try it. The Saber felt good quality; if you close your eyes, it feels like swinging any other racket.

The cosmetics also look good, and the paint job is high quality. I didn't notice at first, but the placard also serves as a stencil should you want to keep the branding after a restring (yes, you can restring it!)

Functional Tennis Saber Playtest

functional tennis saber with ball

Most people's reactions when they first see the Saber is that it must be near impossible to play with. “So many air shots”, “No way you can hit the ball”

However, having used a tennis pointer before, I knew that likely wasn't the case. Yes, it would be more difficult (that's the whole point) but if you have an eye for hitting a ball, then making contact with it isn't something to worry about.

Instead, the questions I had before playing were, could you hit with your usual technique, would it be spin-friendly, and would you have to switch to a more continental grip for a horizontal type swing path for consistency.

After my first few hits, the answers to those three questions were: yes, yes and no.

The Saber plays just like a regular racket; you can hit with your standard technique, you can hit with spin, and you don't have to alter your grip.

My grip is eastern, so fairly conservative anyway, but even those with more extreme grips won't have any problems.

From the first playtest, my biggest surprise was how much top spin you can generate with the Saber. 

Despite the head size being not much bigger than a tennis ball, you can still generate plenty of RPMs on the ball, and I almost felt like the ball had more spin on it than the ball I'd been hitting last week when reviewing Toalson Rencon Devil Spin in my VCORE 98. Possible? Not sure, but it felt like it.

You can see Stan Wawrinka using the Saber below, hitting standard groundstrokes.

Aside from the spin and it playing like any other racket, the most significant plus point of the Saber, in my opinion, is that it allows you to hit the ball intuitively.

I am a big fan of letting players hit the ball naturally. Learn the fundamentals, but let your natural genetic predispositions come to the fore for striking the ball.

I think the Saber facilitates that as you have to focus heavily on the ball rather than thinking about coaching buzzwords like racket lag, pronation etc.

Things went awry for me when I started overthinking my shots and thinking about form. If you watch the ball as closely as possible, most other things slot into place. 

You can see my first few hits with the Saber on the ball machine in the video below, where I hit some forehands and backhands, then switched to the wooden racket-type forehand to see what it felt like.


Aside from the obvious training aspect and improving hand-eye coordination, the Saber is also a good ‘reset' tool to get you back to basics.

If you played a bad match or had a hitting session where you felt like nothing worked, then picking up the Saber resets your mind and makes you focus on the only real thing that matters – hitting the ball cleanly and getting it over the net. 

At 37 square inches, which isn't much bigger than a tennis ball, you don't have enough margin for error to let your mind wander or take your eye off the ball. 

Who is the Saber For?

saber sweet spot tool vs regular racket

The Tennis Saber has several uses. The most obvious one is for the individual player.

If you're a keen tennis player looking to improve your ball striking ability, having this in your bag to warm up with and train with is ideal. 

When I first tested it, I planned to hit 100 balls with it from the ball machine and then switch to my regular racket, but I ended up hitting 300 balls because it was super fun.

Is that just the novelty aspect? Maybe and it will be interesting to see how often I'm using it a year down the line. (If you're reading this from the future, leave a comment below and ask me.)

However, based on my first two sessions with it and how it feels to hit the ball with your regular racket afterwards, I can see myself using it pretty often as it makes the game feel more effortless.

If you have a regular hitting partner who also gets one, you could even play a match with it. It would undoubtedly be error-strewn when hitting on the run, but highly entertaining, and as a mini warm-up or forfeit type game a la Djokovic, I could see pro players using them.

It's also a helpful training tool for coaches to pull out of their bags and give to their students. Even for players new to the game, the Saber will make them watch the ball more closely and force them to work harder, which can only be good for development.

The Saber also works well as a tennis-themed gift; buying a racket for someone is tricky as you don't always know their specs, preferences etc., but because the Saber is a one size fits all, it works for all players of all ages. 

Common Questions

Can you restring the Saber?

Yes, you can. The Saber comes prestrung with a synthetic string that should last a long time, and you don't need to worry about tension. But if it broke, or you wanted a different string, then you can restring it using the badminton attachment for a stringing machine. Or using the improvised method below:

The recommended tension is between 25 and 30 lbs (11 kg – 13.5kg).

Can you hit the ball normally with a Saber?

Yes, you can hit the ball just like a standard racket. The more pace on the incoming ball and the harder you try, the more chance for a mistake, but the Saber is more capable of withstanding heavy balls.

I have arm issues. Will the Saber be ok for me?

I am not a player with any elbow problems, but the Saber felt super comfortable to me. I do not have the RA rating for stiffness, but my guess is low 60s.

It is a soft-feeling frame, and with some fibreglass in the construction + synthetic nylon strings, there is no harshness to it at all.

The racket I play with is much lighter than the Saber; should I use it?

The Saber comes in at 312g strung, roundabout the racket weight that most adult males should be playing with.

However, even if you play with a much lighter frame, the weight of the Saber should be manageable, and heavier frames help promote better stroke mechanics. 

With such a small head size, the weight naturally has to be in the handle, resulting in a ~270 kg/cm² swing weight So even if your racket is lighter in static weight, this is likely easier to swing.

Functional Tennis also has some plans to launch a lighter version in around a year.

Final Thoughts

saber training tool


The Functional Tennis Saber takes the classic wooden tennis pointer, invented by Czech coach Jiri Bartos in 2011, to another level.

It is a high-quality training aid that is fun to play with and will improve your ability to hit the ball cleanly.

You'll watch the ball more closely and get into position earlier so that when it comes to hitting with a more forgiving racket, you will ‘middle' the ball more frequently, resulting in more power and less vibration back into the arm for a higher-quality shot.


  • Slick cosmetics
  • It feels well-made/high quality
  • A simple concept that's proven to work in tennis and other sports


  • None I can think of so far. I will see how the grip holds up over time and update this if I spot any drawbacks with the Saber.

What do you think of the Functional Tennis Saber? Have you tried any similar training tools? Any positives or drawbacks I missed? Let me know in the comments.

Functional Tennis Saber Review

Build Quality
Packaging / Delivery


A super useful bit of kit for players and coaches who want to practice hitting the ball more cleanly and improve their hand eye coordination.

Get The Functional Tennis Saber
User Rating: 4.78 ( 4 votes)


Huge fan of Roger Federer. I watch all his matches from Grand Slam level right down to ATP 250. When I'm not watching or writing about tennis I play regularly myself and have a keen interest in tactics, equipment and technicalties of the sport.

Related Articles


    1. They are pretty similar. Both got fibreglass in the construction.

      The Toalson is 60 square inches and has two weights: 300/320g

      The Saber is 37 square inches so almost half the size.

      Both achieve the same outcome. I think the Saber might edge it just because it’s smaller so is more challenging. The Toalson is more like an old-school tennis racket, whereas the Saber is like a mini-modern racket.

  1. I have used for this occasionally Rod Laver’s Dunlop Maxply Fort (not customized and no idea, when it was manufactured) or Slazenger Victory. Could not even find the head size of them. Visually I would say 60″, so middle of the way between current standard 98/100″ and the Saber’s 37″.
    What’s the sweet spot of Saber itself? Is the whole head sweet spot?
    One obvious advantage over old wooden rackets must be the static/swing weight, simulating modern rackets.
    You say it feels like “normal” racket, only the head is a bit smaller 😉
    I would buy the Saber if I could find a partner eager to do the same and play matches with me with this racket 🙂

    1. Yeah wooden racket has the same effect. Like you say though not quite simulating a modern racket. Might struggle to withstand heavy hitting as well an older frame?

      Good question, I don’t really like the term sweet spot but I’ve kinda started using it just because everyone does and that’s what these training aids are often called.

      The actual sweet spot is just a single point on the racket where there is zero vibration and zero rotational force. So headsize is basically irrelevant, it doesn’t get bigger or smaller depending on how many square inches, it is one single point, not an area.

      Maybe ‘middling’ the term used in cricket is better, this tool teaches you to middle the ball more often as you have a much smaller area to do it with.

      1. I’m also wondering, if hitting sweet point (or middling) is just what pro players need. They need rather to hit just the point on the racket they want to achieve some special shots. Looking at shots in slow-motion you often see they hit very close to the frame and it does not look like mistake but just like what they are aiming to do. Often adding some special slope and some more complicated positions in more than one plane.
        I can hardly imagine the Saber could be useful to train anything other than just hitting the center. Maybe it helps to have general control on shots, so after you have learned to hit the center, you can hit with same precision any other spot on the racket’s head?
        When hitting with the old wooden racket I have observed, I’m automatically focusing more on hitting the center, because on my level I would have no control if hitting too far from the center, so I’m always (automatically after longer training I guess) trying to hit the center and eventually add some slope to lift the ball or to play topspin or slice.
        But it’s probably good for recreational players (probably not at the very beginning but first after they have learned to hit the ball, not the air ;)) to learn the control. The less tolerant the racket (racket with such a small head must be rather intolerant), the more distinct the answer from the racket “you didn’t hit the center” 😉
        And for more advanced club players (like you) it could be nice challenge to play points with this kind of racket. Not sure if the only difference vs. normal racket is the head size? Or you simply cannot create some shots with it?

      2. No chance that players are purposely hitting near the edge of the frame. That is where you get the most rotational force, most vibration etc.

        All players are looking to hit the ball in the spot that produces the best shot for them. It’s not going to be the exact same for every player as different length rackets, head shapes etc, but it’s always going to be somewhere roundabout the middle.

        All his best shots are out the middle in this video:

        You could play a match with the Saber for sure. On the run, it would be difficult as way less margin for error but it’s good training. I have drilled on the ball machine with it oscillating from side to side, not easy.

      3. Now I’m a bit confused. Close to the frame’s edge was maybe exaggerated, but just like on your slow-motion I don’t see many shots with ball hitting very close to the head’s center, so assuming the sweet spot is actually a point, they probably intentionally hit the ball with a certain part of the head, but ot’s not often the middle.
        I think, we may assume, after hitting zillions of shots in training, they should be able to hit most shots very close to the middle, if it was the ideal spot for every kind of shot. Or I have misunderstood you?

      4. While using Saber with ball machine what’s your goal? To reach the ball and hit it somehow over the net into the court or it’s to get optimal shots, which you would be able to hit with normal racket?

      5. Yeah, the term middle I guess is also confusing. As in cricket, it doesn’t quite mean the exact middle as in exactly halfway up. It just means the area where it feels best, which can’t really be anywhere else other than *close* to the middle. Same for tennis.

        My goal when using the Saber is to hit the ball as cleanly as possible and land it on the other side of the court. And to make as many balls in a row as possible. Nothing much else.

      6. So quite the same what you would go for when using ball machine with normal racket, but with more effort and lower count of good shots, right? The same drill but tougher.
        Do you play one-hander? If so, how does Saber fare on one-hander? More difficult than on forehand?

      7. Yeah pretty much, although with a normal racket I do different drills as you can set my machine to follow set patterns, so 2 ball cross, one down the line etc. I haven’t done that with the Saber much. Mainly hitting with the machine set to a fixed position. Or only slightly oscillating.

        Ye OHB. Backhand for me is easier as that is a more natural shot.

      8. Funny, you are the first one from whom I hear, SHB is more natural than forehand 😉 Maybe because most recreational players are playing DHB, thinking it’s easier to use both hands (maybe in terms of stability and easy power, but not the motion of the whole body) , so they believe, forehand is more natural. Well, for them it is, because it’s still played with one hand, while they never played single handed backhand.
        No, sorry, one of coaches I had some lessons with (the last one) told me the same, but this was in context of my game. I always need to hit more forehands to reach my normal level than with backhand. When starting drills or hitting with partner I always feel somehow stiff, am opening the racket and holding the arm too close to the body.

    1. I’m giving it the odd bit of attention in terms of results and betting, but I am also part boycotting it as I think the tournament is a joke for banning Russians and Belarussians.

      The event has been a complete flop this year, the crowds are wayyyyy down (Federer effect not to be underestimated), the scheduling has been poor, and just the whole atmosphere to the tournament is ‘off’

      TVR has served well so far, winning 90% behind first serves, I think he will cause some problems but be a tough ask to win. I guess the centre court is also slower, so that favours Djoker.

      1. I’m boycotting too for the same reason. Kind of happy to see Hurkacz (offered 100$ for cannons for every ace) and Swiatek (running around with blue-yellow sticker and participating in a pro-XX event) out.
        Additionally no Federer and no Thiem.
        Somehow rooting for Djoker or Nadal.
        Thiem is going to play Salzburg Challenger, starting Tuesday (for him). Has practiced last 10 days in Barcelona with Rublev, so hope, he will come out firing. But no expectations actually until he shows his progress in a match and at least restore the fighting spirit.
        Some news about Fed’s rehab?

    2. Yeah Hurkacz bringing out the lame virtue signalling. If he was around in 2011 would he have given $$$ for every ace he served to Libya? I doubt it. As usual the normies have no clue what’s going on. Gonna be a long cold winter for Europe.

      Federer is at Wimbledon today. Be in Royal Box I guess. No other news.

      1. Well, Royal Box could be probably the new Wimbledon place for him for ever 😉
        BTW – long not followed crypto but just looked yesterday at market prices and it looks like after an earth cake – what’s the reason? Ukraine?
        Cold winter – yeah, right now fire wood costs 4-5x the price from before 24.02. I had luck to have purchased my usual replenishment (every 2 years, for 3 years seasoning) with old prices so I have now wood for 3 coming seasons on the racks 🙂 As for inflation I have found a simple solution. With inflation around 20% I simply need to translate 20% more 😉 With hyperinflation would be no more so easy. Or must find a way to invest in rubles, hahaha

    1. Yeah, you could put a poly in it, I think it would feel pretty good as it’d be super low tension. Bit like a poly in a wooden frame which I heard a few people says plays nicely.

      I might try it but not going to cut out the strings it came with as it looks a bit of a faff to restring, so will wait until it needs doing.

    1. Look for an old wooden racket like Dunlop Maxply Fort or other. It’s available on Polish auction platforms for around 25 EUR. You restring it and can have quite the same effect. Only the racket is a bit heavier.
      IMO you can actually do the same drills with your normal racket. Your wrist, forearm and elbow (and the sound of the strings) will tell you, if you hit the middle.

    2. Yeah, not the cheapest but I don’t think it is too bad a price. Trying to think if one of the big brands sold it, would it be any cheaper even though they have way more scale? Probably not.

      I feel like I will get decent value out of it. Be good if the Saber + shipping was €149.99 all in, that extra shipping cost might lose a few orders from those on the fence about buying it when they reach checkout.

      Tennis gear pricing is surging really, I remember when the premium rackets were close to $100. Now they are going way above $200. The same story with cricket bats, when I was younger and looking at all the best bats, £100 was like whoaaaa, now they are like £400 😀 and they don’t last half as long.

      If you are on a tighter budget, Artengo has the best value tennis products. I will try to review some of their gear soon.

  2. A few weeks on from writing this review – still using the Saber and enjoying it. I’ve warmed up with it for probably 80% of times I’ve played since this was published.

Leave a Reply

Your email address will not be published.

Back to top button