Gorilla It Out

After a hand has been lost the partnership needs to find out if the hand was actually mathematically possible to win. Some hands can be quite tricky to analyze. Fortunately, there is an algorithm that will work for any hand. This is the Gorilla algorithm. To apply the algorithm to a hand is to Gorilla out the hand or to Gorilla it out.

To Gorilla out a hand each player has four areas for cards. The taker's four areas are labeled to play, played, blocked, and run. The giver's four areas are labeled to play, played, pitch, and keep,

The algorithm starts with each player's whole hand in his respective to play areas. During the first phase the team works through all four suits and moves all cards out of the to play area into one of the different areas.

For phase one, go through each suit and do the following steps:

• If the taker has cards in the suit:
  • If the giver has cards in the suit and at least one of them is lower than the taker's top card then the taker puts his highest card in that suit into the played area and the giver puts the highest card that is lower than the taker's card into the the played area. The algorithm continues with the same suit.
  • If the giver is out of the suit then the taker puts all of his remaining cards in the suit into the run area. The algorithm continues with the next suit.
• If the taker is out of the suit then all of the giver's cards in the suit go into the keep area. The algorithm continues with the next suit.

Phase two begins when there are no remaining cards in either to play area. Phase two steps:

• If all cards are in played then the hand is possible. The algorithm ends.
• If the taker has no cards in run then the hand is impossible. The algorithm ends.
• If the taker has no cards in blocked then the hand is possible. The algorithm ends.
• If the giver has no cards in keep then the hand is impossible. The algorithm ends.
• If the taker has no cards in pitch then the hand is possible. The algorithm ends.

In phase three the partnership figures out which suit is the next suit to attack. The only way to be in phase three is if taker has cards in both run and blocked and giver has some cards in both keep and pitch. Phase three steps:

• Count the number of cards that taker has in run. Call this number runcount.
• For each of the suits that giver has represented in pitch:
  • Count the number of cards that giver has in that suit in pitch. Call this number pitchcount.
  • If runcount is greater than or equal to pitchcount then this suit is a candidate suit, otherwise it is not.
• If there is no candidate suit, then the hand is impossible. The algorithm ends.
• For each of candidate suits:
  • Take the number of cards in the suit that taker has in blocked and subtract from it the number of cards in the suit that giver has in pitch. It is not a problem if this number is negative, just remember that positive numbers are bigger than negative ones. This number is the surplus for the suit.
• Select the suit with the largest surplus. If there is a tie select one of the tied suits.
• As long as giver has at least one card in the selected suit in pitch:
  • Taker takes one card out of run and moves it to played.
  • Giver takes the highest card from the selected suit out of pitch and moves it to played.
• Taker moves all cards in the selected suit from blocked to run. The algorithm continues by beginning phase two again.