Speed: what it really measures and what it does not

Few words in equipment generate as much misunderstanding as speed. It appears on spec sheets, in reviews and in club conversation, always accompanied by a number that seems to indicate how fast a bat or a rubber is. The number exists, but what it measures is not what most people assume.

When a manufacturer assigns a speed figure to a rubber or a blade, it is recording the result of a standardised strike under controlled conditions. That figure is reproducible within its laboratory and comparable — with reservations — between models of the same brand. What the player experiences at the table is something else: the result of a chain involving blade, sponge, topsheet, glue, arm strength, angle of attack and the particular ball. The first fits into a number; the second does not.

Within real play it is worth separating at least three speeds that tend to get mixed up. Outgoing speed is how quickly the ball leaves the bat after impact: it determines how much time the opponent will have to react. Bat speed is how quickly the bat is travelling at the moment of contact, the result of the player's stroke: a human variable, not a material one. And the intrinsic speed of the system — the one manufacturers set out to measure — is the efficiency with which a bat converts bat speed into outgoing speed. How much the system multiplies the energy the arm delivers to it.

All three are speeds, but they are not the same thing. A player with a strong arm and a medium-speed bat can produce a greater outgoing speed than another with a medium arm and a fast bat. The same model can feel quick in close rallying and apparently slow in counter-attacking at mid-distance, because the efficiency of the system depends on the impact regime. Above a certain force threshold, modern tensor rubbers raise their efficiency non-linearly — this is the catapult effect covered in 2.4. That means the same bat can be “slow” in the short touch and “fast” in the open stroke. A single number does not describe that behaviour; it averages it, and in averaging it, hides it.

The speed of a bare blade and that of the same blade with rubbers are not the same magnitude, nor do they add up as though they were stackable figures. A fast blade with a soft sponge can produce a surprisingly controlled assembly; a slow blade with a modern tensor can yield a fast bat. The relationship between component speed and assembled speed is developed in 8.5 and in 11.1.

There remains the misunderstanding the industry deliberately feeds: the idea that a bat is, in itself, fast or slow, as though it carried the speed inside it. A bat does not have speed; it has a response profile describing how it behaves under different impact regimes. When a catalogue assigns “speed 13 on the Butterfly scale”, it is not lying: it is answering a specific question with a figure useful for comparing that rubber with others from Butterfly. Outside that internal comparison, the figure loses much of its meaning. Why the scales are not comparable between brands is explained in 2.8.

The practical consequence is brief. When one reads that a bat is fast, it is worth asking in which regime, with which rubber and for which player. The speed figure is a clue, not a measurement.