Which is softer – a multi, or low tension soft poly?

These days, there are soft poly options with very attractive low stiffness numbers. You can put some polys side by side against a multi and they have similar stiffness ratings, and both are for players where comfort is a priority. So why wouldn’t you take the poly?

They’ll get more spin, are cheaper, and will last longer before they break than the multi – so just go with that right?

You’re missing a big part of the picture. Both have their pros and cons, but what’s better for you? Zoom out for a second and let’s talk about why string stiffness numbers are only one part of the comfort conversation.

For this post, we’re just going to be talking about full beds.

Polys are different than they used to be. There was a time when a “soft poly” was rare, and now there are so many more soft-labeled options available.

Just because it’s labeled soft, don’t let the term soft poly fool you - a lot of them aren’t actually soft like you're thinking. Take a metal like steel – there are harder steels and softer steels but they are still metal. Luxilon 4G Soft, for example, is not a soft string at all really. It’s a softer feeling, softer responding version of the beast that is 4G - one of the stiffest strings out there.

I play with soft poly and I love them, but I’m not trying to promote it. I want to address a trend I’ve been seeing on the forums, on social, and in real life. One player asks for some recommendations for a nice multifilament to help protect some arm issues. The responses they get back are alarming.

4G, Hyper-G, Alu Power, all advanced polys, are some of the responses back. They are popular but completely the opposite of what some are looking for, or even want.

There are some very soft polys out there that rival the comfort of multi. The softest polys like Isospeed Cream and Yonex Poly Tour Air are in a category of their own. It’s still a poly, but they have elastomers added (think rubber) to get extra stretch and give that other polys don’t get, and can achieve a similar stiffness rating to some multi’s on paper. 

While those polys can feel very soft initially, and I’d recommend them as a starting place, their comfort properties are ephemeral – lasting a short period of time – when compared to the multifilament. 

Once the elastic properties of the poly wear out, typically around 6-12 hours (maybe it’s 20 hours for you) those low stiffness numbers you fell in love with are gone. The string bed starts to lock – when notching prevents the string from sliding around freely – making the bed feel stiffer. Your comfort setup is not so comfy anymore, and since it most likely won’t break yet, you must cut it out if you need the comfort.

This is where many go wrong, they rely on the poly like it’s a multi and overplay on the string. The clock is ticking - it has a peak period, then it falls off.

And that’s where multi shines, is time.

Multifilament will continue to stretch and retain its comfort properties through much of its life. They don’t have that sharp falloff in comfort you get with the poly. No, not all multi’s are made equal, some do this better than others. But in general, this is where the multi is superior to polyester for softness over the long run.

So while multi may not seem as attractive on the surface from a spin and performance perspective, if comfort is your top priority, you’re not a big string breaker, and you want less restringing, stick with the multi. Your arm will thank you.

If you must have the spin, the feel, and more peaky performance of the soft poly, make a note of how many hours you get until things start to stiffen up and how your arm is feeling. Plan to keep up with the restringing, and don’t push it too far past your limit.

Numbers are just numbers. Everyone’s level, racket, arm, and string setups are different.

Your tennis background and your journey ahead, is unique to you.