Balls, Nets and Robots

Buy three star 40 mm plastic balls and train with the ball you compete with. Replace the sagging net that came with your table before spending on anything else. A robot is a real tool for grooving a repeatable stroke, and poor value unless you use it most weeks. In that order.

The star rating is a roundness grade, not a durability grade

One, two and three stars describe how close a ball is to a perfect sphere, how evenly its weight sits, and how consistently it bounces from ball to ball. They say nothing about how long it survives. A three star ball cracks under a smash like any other, sometimes sooner, because the tolerances that make it round do not make the shell tough.

What roundness buys is a ball that does the same thing twice. An out-of-round ball wobbles, bounces off line, and grips the rubber unpredictably on serve, so you blame your technique for errors the ball caused. That is the whole argument for the higher grade.

40 mm plastic, and what that changed

Modern balls are 40 mm plastic rather than the celluloid the sport used for decades. You will see them marked 40+, reflecting the slightly larger, seamless moulding most makers use. Against old celluloid they are marginally harder, less lively and carry a little less spin, which is why coaching written in the celluloid era describes serves that no longer bite quite as promised.

Practically this is not a decision: any ball you buy new is plastic and 40 mm. It matters only when someone hands you a bag of old balls.

Train with the ball you compete with

Balls differ enough that switching between them changes your timing. A cheap ball flies slower, sits higher off the bat and takes less spin, so a loop that lands deep in practice drops short in a match. If your club uses a particular grade, train with it. This matters most in serve practice, where a different ball changes where the serve lands.

Balls also wear in a way that is easy to miss. Hard hitting deforms the shell and repeated contact flattens spots, so long before a ball visibly cracks it has gone out of round. The first symptom is not a wobble, it is a ball that bounces slightly differently each time. Spin a suspect ball on the table: a good one spins smooth, a tired one hops. Cracked balls belong in the bin, not the practice bucket: they teach you to correct for faults you will never meet in a match.

What a decent net and post set changes

The net that ships with a cheap table is nearly always the weakest item in the box, and replacing it is the cheapest meaningful upgrade in the sport. Two things separate a good set from a bad one. Tension: a screw or ratchet adjuster, so a ball clipping the cord drops on your opponent's side rather than dribbling back. And consistent height: solid clamps and posts that do not lean, holding the regulation 15.25 cm across the full width.

A sagging middle quietly ruins practice. Down the centre the net is effectively low, so a flat drive that should have caught the tape gets through while the same shot near the sideline does not. You learn a margin that does not exist.

Training robots, honestly

A robot fires balls at a set frequency, spin and placement. It is genuinely good at repetition: the same ball, same spot, hundreds of times, which is what building a stroke requires and what a partner cannot deliver consistently. To groove a forehand loop against backspin, it is the most efficient tool available.

The limits are worth stating. Below a certain level of commitment the value collapses: a robot is a significant purchase, it needs a hundred or more balls plus a collection net, and without that net you spend half the session picking balls off the floor. Cheap machines feed one spin, one speed, one spot, which suits a beginner drilling one stroke and gets boring within months. Oscillation and programmable drills are what make a machine last, and what costs money.

And a robot never reads you. It does not disguise spin or punish a return you left high. Train heavily on a machine and you can end up with a clean stroke that falls apart against a person, because you have practised execution and never practised reading. Use it between sessions with people, not instead of them. It also puts a lot of contacts through a rubber, so heavy drilling wears the topsheet faster: see rubbers explained.

Where the money goes first

Where you are	Balls	Net	Robot
Family table, occasional games	Any decent plastic ball	Whatever came with it	No
Practising regularly at home	Three star, bought in a box	Replace a sagging set	Not yet
Club or league player	The grade your league uses	Proper tension adjuster	Worth it if used weekly
Coaching juniors or a group	Bulk balls of one grade	Good set on every table	Yes, with oscillation

Keep two supplies: a match box used only with a partner, and a practice bucket. When a practice ball starts to hop, retire it.

Common mistakes

Reading stars as toughness. Three star balls are round and consistent, not armoured. They crack too.

Practising with dead balls and competing with new ones. Different flight, different timing, discovered mid-match.

Buying a robot before a net, balls or a decent table. The machine only amplifies the surface it feeds onto. Sort the table first.

Questions people ask

How many balls do I need?

For playing, a box. For robot or multiball drills, a hundred or more of a single grade, so the feed is consistent and you are not stopping to collect every two minutes.

Are one and two star balls useless?

No. They are fine for warming up and for junior sessions with a lot of loose balls, anywhere the flight of each individual ball does not matter. Keep them out of serve practice and match play.

Is a robot better than a wall or playback mode?

Yes, for one reason: you can set spin and placement. A wall returns what you gave it, faster and flatter. Neither replaces a session against a person.