Doubles Principles 12 Changes Per Lead Bell Methods Carter Doubles Doubles principles (12 changes per lead) Clappers Orchard Doubles Doubles principles (12 changes per lead) Eurydice Doubles Doubles principles (12 changes per lead) Lulys Ope Doubles Doubles principles (12 changes per lead) Newton Valence Doubles Doubles principles (12 changes per lead) Parsnip Doubles Doubles principles (12 changes per lead) Reverse Carter Doubles Doubles principles (12 changes per lead) Reverse Stedman Doubles Doubles principles (12 changes per lead) Stedman Doubles Doubles principles (12 changes per lead) Wiggle Doubles Doubles principles (12 changes per lead)