The rules for Clock can be found here.

There was really no need to write a simulator for Clock, as the win rate was already long known to be exacty 1-in-13. But depending on how you think about it, you can very easily come up with reasons why the win rate *must* be lower. So with that in mind, I ran 100 billion simulated games of Clock, and the program won about 7.69%, which is indeed very consistent with 1-in-13.

If you like Clock but prefer games with a higher win rate, try playing with all the cards initially face up. Play the same as in the standard version, stopping when you have four Kings in the center. You win if all 52 cards have ended up in their correct clock positions. Played this way, the win rate is above 1-in-5. It may seem counterintuitive that the win rate is different at all, but note that in the face-up version, there is no longer a requirement to flip over every card (in the standard version, the game may end as a loss with one or more cards still face-down, but in the correct clock positions; in the face-up version, these deals become wins).

Clock Solitaire Results,
100 billion deals each
Rate %

See Eight-Day Clock for another way of playing solitaire with a clock-like layout.

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Last modified April 29, 2022

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