Clear pairs that sum to thirteen across a packed 13-pile tableau, where a King goes solo and only about 30% of deals reward you.

Friday Solitaire is a pair-removal game played on a 13-pile tableau: ten outer piles dealt three cards each and three inner piles dealt just one card, with the rest of the deck held in the stock. Clear any two cards whose ranks add up to 13 (a King can be cleared on its own), and the three inner piles refill from the stock as they empty. It's a medium game with real bite: only about a 30% chance of winning, and luck plays a bigger part here than skill.
It's cut from the same cloth as Pyramid Solitaire, the game that made summing to 13 famous, and it shares that same rule with Thirteens Solitaire and Links Solitaire.
If you run into anything odd or have an idea that would make the game better, please contact me.
Enjoy playing!
13 tableau piles: Ten outer piles start with three cards each, and three inner piles start with just one card apiece, all dealt face-up with the top card in play. Clear any two cards whose ranks sum to 13; a King can be cleared alone. The three inner piles refill automatically from the stock as they empty, but the ten outer piles stay empty once cleared.
Stock: Refills the three inner tableau piles as they run out.
Foundation: Four piles where cleared cards are set aside, out of play.
There are four foundation piles, where cleared cards are set aside out of play.
The stock is made up of leftover cards.
Cards cannot be withdrawn from the stock manually.