How much do speeds increase with gut?


I play with full poly but curious as to speed gains on serves and strokes if i hybrid with natural gut. Say I max my serve at 96mph with full poly, what could I possibly max at if I hybrid with natural gut?


-this would be a good test to try with FB string jobs on day 1, day 3, week 1, month 1, test period
-im thinking, all you need is a speed gun for the serves, and similar playing conditions (indoor or outdoor), throughout the test periods


I assume you are talking about increase in horizontal velocity. You did not mention parameters such as tension differential between poly and NG. If you use the same tension as you have for the poly, the ball will definitely start to fly longer, probably more then 5%. You can serve 4 DF every time you serve your game. If you start to tighten up the NG tension, you will decrease the horizontal velocity and maybe get the ball in on serve. Thing is you need to consider spin and by the time you factor that in by changing service motion etc, you may be back at your point of origin. I suspect that it will take several hours of hitting and multiple string jobs before you can decide. If it were me, I would opt to decrease tension in the poly by 4# and see what that gets you.


I tried gut hybrid once after nothing but full poly for about 50 years and it was a rocket launcher. Same racquet and tension but same shots were out by 10 feet. So I'd say the power level increased 10 or 15 mph.
I tried gut hybrid once after nothing but full poly for about 50 years and it was a rocket launcher. Same racquet and tension but same shots were out by 10 feet. So I'd say the power level increased 10 or 15 mph.
Are you sure poly string was available 50 years ago?..
You can’t string natural gut at the same tension as the poly. For example I use poly and ng blends often. I tend to string full poly setups in the 48-52 range depending on the racket with same tension in cross and mains. When doing the ng hybrid with poly I always put the ng in the mains and string 4lbs tighter than the poly cross. You’ll still get a little more power out of it, definitely more feel and comfort, and with similar spin/control.

If you’re really looking for more power lowering the full poly tension is cheaper. If you’re looking for a sudden jump in speed like 5mph avg you will start to feel like the ball is launching regardless of the string.


I would say no significant increase. I have played with gut/poly and poly/gut hybrids. But then, I am more sensitive to the feel and sound of the ball off the strings than actual speed.


Hall of Fame
I've been testing myself every year since 2015. Once a year I restring my racquets to check if I'm serving any slower as I age. Playsight Pro analyzed, using fresh strung 16g VS Touch 1.3mm (59lbs) vs Volkl Cyclone 1.1mm (48lbs) with Pro Red Code Wax 1.2mm (55lbs for gut, 46.5 for VC) crosses on 3 matched swing/twist weight/balance SV98+. I had about avg 2.7% mph overall increase for 1st serves that were in. RPM is supposedly up by 4%, but well within the margin of error so it can't be really accurate.
In real world, the difference isn't drastic but certain serves are better for me. My deuce court wide serves come in 8% more often with gut, because the added power carries the ball over the net. Funnily, I got a bigger increase in speed with the RF97A, a 3.2% mph gain, but I strung it lower too.


Swing weight is going to have a much bigger effect on the speed increase of the ball compared to the strings.
Strings & tension affect the launch angle of the ball off the strings causing it to go 'deeper' or shorter in the court.
To some extent the properties of the strings will have a higher or lower energy return but it will be a few percent, not a large difference.


Thanks to Sardines for actually going through the effort of providing actual data.
Anecdotally, it matches what I see. I play best with full poly because I need control more than extra power. I've been using gut mains and poly crosses to save my arm.
Full gut is most powerful and gut/poly next. Full poly definitely has less power.


At least try a hybrid set up, it is worth it, an experience you need to have: power with control.

And besides, many pros use this set up... try to see what they feel.