: It is designed to be "maddening" because the usual strategy of sorting by flat edges doesn't work.
: Developed by inventor Simone Giertz and sold through her shop, Yetch Studio . Assembly Tips for "Edge" Puzzles The Edge
: In the "Summer Day on the River" version, 408 out of 512 pieces are edge pieces. : It is designed to be "maddening" because
: Popular designs include Summer Day on the River and Birthday Heist on the Hillside . The Edge