The Clock (patience)

Four layers of cards in alternating colours are built on each foundation.

In the accompanying image from a software implementation of this game, both the stock and waste are inside the Clock; when playing the game with a real deck, you would hold the stock in your hand and put the waste outside the Clock.

The foundation base suit is determined by the first card drawn and played.

Foundations are built by alternating colours, starting with the card of that rank in the base suit.

If a usable card is missed, the game becomes harder to solve.