Different Generations of Poly Strings

Despite having been around for about three decades now, many still seem to have misconceptions about poly strings. 

From its infant days, poly has come a very long way. Broadly speaking, we are now in the fourth generation of poly strings.

Without referring to specific brands or models, the first generation poly string was simply slick, stiff and dead. Nothing else.

Elasticity was so low that every ball impact took some tension off through string deformation. String life was so pathetic that it was probably better monitored by the number of shots one hit, rather than by time used.

While the spin was hugely rewarding, the stiffness must have affected quite a few players. As a result, a second generation of poly was born.

Additives were added to soften the string and the term co-poly surfaced. When strung within a specific tension range, from about the mid-40s to low-50s lbs, a higher level of comfort was achieved through greater elasticity. 

Within this range, tension holding also improved. However, when strung below or above, it still played as boardy and stiff as the first generation.

I believe it was from this generation of poly that caused many misconceptions about poly's useful tension range, up till today.

The third generation poly was heavily marketed with more "bite". That was when shaped co-polys came aboard. Five-sided pentagonals, hexagonals, spirals, twisted and fused, and many with rough edges became wildly popular. Comfort improved further.

The most popular fourth generation poly string now is Luxilon 4G. Aptly named, as "4G" simply refers to fourth generation. Tension holding and comfort were touted to be "uncommon for a poly".

Somewhere around the third or fourth iteration, the useful tension range widened tremendously. Many reported great results from as low as 20+ lbs (link), to as high as 90 lbs! Yes, with full poly!

Personally, I have tested quite a few between 30 to 70 lbs. Surprisingly, at either 30, or 70 lbs in the same racket, it played almost equally boardy! But the one with lower tension loosened up much more rapidly, whereas the tighter strung took about an hour to "break-in" before playing well. 

I could not find much difference in the amount of spin between the four generations. Variances were only on comfort and tension holding.

Whichever generation of poly it is, keep in mind it was introduced solely to generate tons of spin. To achieve that, it has to be made very slick and very stiff to snap back effectively. Slick and soft would not work as well for spin.

As a result, poly demands a strong loading to play well. And that could mean very long loopy full swings, or rackets with high swingweights and open string patterns. 

Tennis balls that are a little heavier, have high bounce and are "hard like rocks" for natural gut or synthetic gut could also possibly help with the string loading required. Just be wary of your own shoulder, elbow, arm or wrist tolerances.