Lower tension is not more power, it is more forgiveness

The standard claim about loose strings is mostly wrong, but the reason players like them anyway is real and worth understanding.

The received wisdom is that lower tension gives you more power. The physics behind it is that a looser string bed deforms more and returns more of the ball's energy, and there is something to it, but the effect is small and it is easily swamped by what else changes. Players who drop tension and hit the ball further are usually hitting further because the ball is leaving at a different angle and with less spin, not because more energy came back.

What lower tension genuinely gives you is a bigger sweet spot in practical terms. Off centre hits lose less, the frame twists a little less violently, and the shot that would have died on a tight bed still gets to the baseline. That is forgiveness, and forgiveness is worth far more to most players than power, because most players do not miss because they lacked pace.

The cost is directional control. A softer bed holds the ball marginally longer and lets it move across the face, which means the exit angle depends more on exactly how you struck it. On a clean hit you may not notice. On a stretched defensive ball you will, and that is precisely the shot where you needed the racket to be predictable.

So the real trade is not power against control. It is forgiveness on bad contact against predictability on desperate contact, and which one you want depends on how you lose points. If your errors cluster around mishits in the middle of rallies, go looser. If they cluster around wild balls when you are on the run, go tighter and accept the harsher feel.

Almost nobody chooses on that basis. They copy a number from a professional whose swing speed, string type and error profile have nothing in common with theirs, or they follow whatever the stringer suggested three years ago and never revisit it.

I would revisit it every time the string type changes, and I would change one thing at a time, which is a discipline that lasts about a fortnight in most people.

Two kilos is a big change. Everybody treats it as a rounding error.