Originally Posted by McLovin
RacquetTune has a 'hybrid' setting, so the tension loss is the overall string bed. Whether it is due to the gut or the poly, I do not know.
BTW, I forgot to mention that the Co. Focus is 17g (1.23mm).
Loss of tension should be larger after one hour
Basically poly may loose 10 percents
Gut should loose around 9 percents