We have tried to test if it works. A recurring problem with testing new equipment etc. is the factor of subjectivity; as you can seldom measure the phenomena involved accurately, you are almost always forced to use your subjective experiences as the only foundation for your judgement. Emotions play a part as well. But we tried to deal with it as best we could. We tested the idea twice, using Re Impact Rapier 44, Swift 44, and T4 both times. I'll call the grooves, counting from the head to the end of the handle, 1,2,3,4 (so much for being original...). The first time we stopped up all possible combinations of these grooves and while two of us played with the blades trying to feel if speed or control had changed, the third watched trying to determine if the trajectory of the ball changed and the sound of the blades. The second time we did the same, but now the two players didn't know which grooves, or any, had been stopped up.
For the first test we stopped up groove 1, then 4, then 1 and 4 both. There seemed to be a slight increase in speed in the latter case; the trajectory seemed a bit flatter, the sound somewhat higher or brighter; but the differences were very slight.
Stopping up 2 or 3 didn't change anything. Stopping up 2 and 3 together, however, did change the sound – it became brighter. The speed seemed to have increased as well, more so than with 1 and 4 stopped up. The feeling was different too: clearer, or more direct. The trajectory of the ball on hits and drives seemed flatter, on soft loops the curve was higher.
Stopping up 2,3,4 and 1,2,3 and 1,3,4 and 1,2,4 made the sound even brighter, the speed somewhat higher, but the feeling wasn't more direct and seemed harder. The trajectory of the ball seemed flatter overall.
Stopping up all grooves didn't do anything more, but made the feel worse: unpleasantly hard.
In this, there were no differences between the three different blades we used.
A day later we went for blind testing. Now the two players didn't know which grooves were stopped up and which weren't. The third one stopped up the grooves, or opened them up again, and the players had to say after a few minutes of playing with them what they thought the number of stopped-up grooves was and which grooves were involved.
The impressions of the players matched the actual number of stopped-up grooves only for about 10% of the time; they were best in spotting the stopping up of grooves 2 and 3, and when these were stopped-up together, they were right more than half of the time.
Still, the third man (who knew which grooves he had stopped up) nearly always spotted the differences in the curve of the ball-trajectory: flatter if more grooves had been stopped up.
We decided that subjectivity was a factor in the observations: players were probably more likely to detect an increase in speed when they expected it. On the other hand: they might feel more accurately what the speed was, when they were sensitized to it by knowing how it was supposed to be different. That is an infinite argument. Still, the fact that the stopping up of grooves 2 and 3 was recognized best, and had the greatest impact (even if it was slight) of all, has to be taken into account. It seems that tuning a blade like this, it is actually affected, if only slightly – but you wouldn't want big changes due to tuning anyway.
Accurate measurement would involve keeping the blade motionless while shooting balls to it with a machine. We didn't do that. Nonetheless, I am pretty much convinced that stopping up the grooves results in a slight change of sound and feel, and also (but with somewhat less certainty) that it affects speed and control. I suspect, however, that the speed of the blades isn't so much increased as more specifically defined by the tuning. Most Re-Impact blades and especially the thicker ones have, due to the way the Balsa works, a speed-range instead of a simple speed indication. Stopping up grooves # 2 and #3 may take away small part of this range, leaving over the fastest part. For instance, the T4 normally has a speed-range ALL to OFF-; if grooves #2 and # 3 are stopped up, its range changes to All+ to OFF-. The difference is small, but may be important, for the blade has now the right basic speed to be effective from mid-distance and is, therefore, easier to play from that distance.
We have tried to come up with more or less convincing ideas about how this type of tuning could actually work in a blade. Balsa contains a lot of air and the sound-waves in it are controlled by the KSLS system; stopping up grooves of this system might work the way stopping up the holes in woodwind instruments works: the more holes are stopped, the higher the tone. A higher tone is related to higher speed, in blades. A higher speed would mean that the speed-range of the blade would decrease, because it would be more narrowly defined, and that would make the blade easier to play with, therefore give it better control and feel. But another explanation could be that stopping up the grooves makes the handle more rigid, therefore the blade more speedy, hence its sound higher. Again, narrowing the speed-range would give better control and feel. And stopping up too many grooves would result in a hard feel.
However this might be, in any case the result of the tuning would be that the speed-range is slightly smaller, the basic speed slightly higher. I am not so sure this is an absolute advantage with these blades – Rapier 44, Swift 44, and T4 – or indeed that it is necessary to tune them for the 40+ ball. In my mind they are doing well enough with the new ball already, as they are, and decreasing their speed-range would also decrease the range you have for variations in speed and spin (especially in soft loops). But for players who want to play faster or easier, tuning perhaps may make sense. It is certainly easy enough to try it out.
[This text was originally posted here: http://ooakforum.com...hp?f=43&t=26918]