Stack Sort

Stack Sort is a puzzle you can finish on the train. Pour the blocks between stacks until every colour sits in a stack of its own. A pour lands on a bare stack, or on one whose top colour matches, so a board is worked out rather than guessed. Sort it in as few pours as you can, and as quickly as you can. Everyone plays the same board on the same day, so the score you post is a fair one. Come back tomorrow and it is a fresh board, with the streak still counting. Free to play: * The daily board, the same for everyone * Practice boards at two sizes, with a fresh shuffle any time * A worldwide board for the day, working offline * Races: two runs of one board, watched as they happen * A streak which counts every day in a row * A spoiler-free result image to share with a challenge * No adverts, and it plays offline A hint is always there, and it costs fifteen seconds. Practice between days. Take on today's board when it lands. Watch the streak build. One colour at a time.