Knockout, I believe that your analogy using a flat basketball is incorrect, because the issue we are discussing does not involve the elasticity or the pressure inside the projectile (ball or shuttle), especially considering that a shuttle does not have any significant abount of inside pressure or other characteristics that would cause it to bounce. The real issue here is the spring effect of the contact surface and that surface's ability to return as much energy as possible to the projectile, thus causing the projectile to accelerate on the rebound from the contact surface. I think a slightly better, although still probably imperfect, analogy might be to consider dropping a medicine ball (weighted leather ball used in weight training that does not have any significant quantity of bounce) on two surfaces from ten feet up, a trampoline and a cushioned gymnastics mat. The ball will bounce significantly higher off the trampoline than off the cushioned mat. In that case, the more spring-like surface of the trampoline will clearly create a higher bounce than the tighter, less elastic surface of the mat.
Another analogy that, while not perfect, might be relevant to this issue is a current subject of hot debate in the sport of golf, namely the tension on driver faces. The USGA has issued an equipment rule that makes illegal for competition any driver that produces a spring-like effect on the ball, as those clubs whose faces deform upon contact and then "spring" back into the ball produce drives that are 4-8% percent longer than those produced by drivers with a rigid (i.e. high tension ) clubface. This issue is covered in some detail in the February 2001 issue of Golf Digest magazine.
Again, I am not absolutely positive that the various analogous examples I have mentioned will apply to badminton. If there is a reason why string tension on a badminton racquet produces a different effect than string tension on a tennis racquet, this layperson would certainly like to know the scientific reason for it.
As for my earlier comments on tennis racquets and strings, I challenge you, Knockout, to find any reputable tennis authority who will tell you that tighter (i.e. higher than the manufactur's average recommended tension) strings result in more power than looser strings. As for your statements about Sampras, his serve was not the fastest recorded serve, at least during the history of the ATP - that record belongs to Greg Rusedski at Indian Wells, California in 1998, who was clocked at 149 mph. (See Tennis magazine, December 2000/January 2001 issue at page 13). Sampras clearly is one of the hardest hitters in the ATP, but the reason is not because his strings are tighter than any other player's - it is because of his strength, athleticsm and skill in hitting the ball in the center of the sweet spot. If power were simply a matter of cranking the strings tighter and tighter, wouldn't other players simply use a higher tension than Sampras so they could overpower him?
Last, I do not profess to be completely knowledgeable on all issues and I certainly make mistakes and errors, as we all do. When I am wrong, I do not hesitate to admit it and make any necessary apologies (which I have already done in this forum). I don't post messages on this board to make controversies or insult people - I participate in these discussions because I want to contribute toward a challenging discourse on these various issues. I am not trying to monopolize any particular topic and I welcome anyone out there to add to the discussions. I try to give examples to clarify my points, although I acknowledge that some of my postings tend to be quite long, perhaps overly long. In many cases when others on this forum have challenged my opinions, they have often used either irrelevant examples (sometimes ridiculously so) or have resulted to childish name-calling and making bald statements that aren't much different than "I'M RIGHT BECAUSE I SAID SO!" If I have made an error, then by all means please point out that error to me, showing me why I was wrong and if you can, please refer to an authority for your contention. I welcome genuinely constructive criticism, as it is an important part of any learning process. If you cannot articulate why you disagree with another person's opinion, and have to resort to criticisms like the ones you made above - groundlessly stating that a person's statements are wrong, personally biased and untrue and labelling the person as immature - then you are merely showing that you do not have anything worthwhile to say and are only venting anger or frustration.
Why don't we all try to use the actual sport of badminton, rather than discussions about it on this forum, to relieve pent-up stress and frustration? Finally, If it gives you any satisfaction or makes you feel better, I will concede that it is likely that you and most other posters on this board are far better players than I am and that I am only moderately skillful and experienced in this sport. Like everyone else, I participate in this forum because I enjoy badminton and would like to acquire knowledge that may help me become a better player.