I may sound like an old record, but it is my humble opinion that a solid and steady tripod is indispensable to sports photography, especially badminton photography. Even with a steady tripod all lenses must be no slower than f/2.8 for zooms and f/1.8 for primes. How can you take consistent badminton photography with slow zoom lenses of f/3.8 and slower hand-held? Hand-holding a slr is equivalent to losing two stops. Just try this : take a picture in a badminton hall at f/2.8 hand-held and take the same or a similar picture at the same f/2.8 with the camera on a solid and steady tripod using a cable release. Enlarge the two pictures 300 times and you can see the difference. You can see in soccer matches professional photographer using expensive and fast long telephoto lenses mounted on solid tripods. You can also see even more amateurs among the crowd using hand-held cameras. I am sure they don't produce comparable pictures. If so the amateurs among the crowd probably know something the professionals have never learned.