The 16 feathers traditionally used to construct traditional shuttlecocks are normally organised in an overlapping spiral arrangement. As a result, the shuttlecock tends to whirl in flight, adding spin-stability to what would otherwise be a more haphazard trajectory. But raising the question, in which direction should it rotate? The Badminton World Federation (which oversees international regulations on shuttlecocks) has very strict and well-defined rules about shuttlecock design. But, puzzlingly, Improbable has been unable to find any mention in the regulations regarding the shuttlecock ‘hand’ – viz. which way it should spin.
Several reputable online sources    assert that the feathers should be obtained from the left wing of a goose. But Dr. J E Morgan BSc, PhD(Exon), CEng, MIM, MIMechE, however, writing in ‘The Enigma of the Shuttlecock’ (The Engineering of Sport, 1996) informs differently:
“A feather shuttlecock, with its ridiculous asymmetric shape, comprises a small cork base (c. 2.5 grams) and a relatively large feather skirt being made up of about 16 right hand wing goose feathers held together with string and glue.”
[our emphasis] For clarification, Improbable has made several enquiries via e-mail to the Badminton World Federation – but so far has had no response. Surely there has to be a standard? As professor Morgan puts it : “… it would be very annoying if one shuttlecock bent one way and the next shuttlecock went the other.” Thus the enigma remains. If any readers, players, manufacturers, enthusiasts etc. can resolve this contentious question, please comment and let us know.
Here are some possibilities :
 It’s always the left wing.
 It’s always the right wing.
 Either will do – it’s the arrangement and gluing that matters.
 It depends whether you’re playing in the Northern or Southern hemisphere.
Note: Badminton players who are also goose admirers might consider using the plastic version instead – but they fly differently … see ‘Shuttlecock aerodynamics : part 3‘