Shuttlecocks explained — feather vs plastic, the verified BWF specs (16 feathers, 4.74–5.50 g, 62–70 mm), and how to choose between speeds 76 (hot or altitude halls), 77 (standard sea-level) and 78 (cold halls). Includes the high-serve test from the back boundary line to dial in shuttle speed on the day, when plastic is fine, and the 2–3 lbs string-tension drop that comes with plastic. The article most people search after their first 'why does the shuttle feel different here?' moment.
