Originally Posted by NLBwell
You obviously don't actually feel the ball on the strings. You feel the vibrations of the racket (racket/string system) which start as the ball contacts the strings and continues long after the ball has left the strings. A looser and/or more flexible string job will respond with lower frequency vibrations than a tighter stiffer string job. These vibrations will be correlated to the dwell time on the racket. Your brain can tell the differences between the vibrations, and then, through experience, will tell you that your are expericencing hitting the ball with a more flexible system (more rubber band-like) or a stiffer system (more iron-bar like).
Of course they will be correlated. Even that does not mean that the ball spent more
time on the racquet, however. Since UCSF just posted a reference, I'll just refer to that whereby if you're rallying hard, you get the feeling of dwell time much more than on a drop shot volley even though the ball spends less time on the strings during the rally. The only point that I've been trying desperately to get across to the OP is that strings which exhibit the feeling of longer dwell time do not necessarily have greater spin potential. The reason is because actual contact times are so similar, and strings, racquets, swing speeds and tensions are all dissimilar among players, and yet the feeling of dwell time for certain strings is pretty much well accepted. In other words: the feeling of pocketing does not necessarily imply greater spin.