If you're here, hopefully it's because you want to create a bot for Hearts League. Here's how to do that.
Hearts is a four-player card game. At the start of the game, each player is dealt 13 cards. They choose 3 cards they don't want and pass (or "sluff") them to the player to their left. Once every player has received the cards passed to them, the player with the 2 of clubs plays it. The person to their left must play a card of the same suit, if they have one. If not, they may play any card. Once each player has played a card, the player who played the greatest card that matched the suit of the first card (in this case, the highest club) wins the trick. They then choose a card from their hand to start the next trick, which follows the same pattern. Players keep playing tricks until they run out of cards. The players then count cards in the tricks they won: hearts are worth 1 point each, and the queen of spades is worth 13. Those points are added to their total score, and the cards are redealt for the start of another round. Rounds are played until one player has accumulated 100 points, at which point the player with the fewest points wins.
There are some corner cases to consider. On the first trick, if a player does not have any clubs to match the 2 of clubs, they may not play a penalty card (a heart or the queen of spades) unless they do not have any other cards, which is extremely unlikely. When a player wins a trick, they may not lead the next trick with a heart if a penalty card has not been played yet, unless their hand only contains penalty cards. At the end of the round, if one player took all 26 points, instead no points are added to that player's score and 26 points are added to each other player's score. This is known as "shooting the moon". The direction in which cards are sluffed changes after every round. In the first round, cards are sluffed to the left; in the next, they are sluffed to the right; next, across; then after that it repeats.
Here is a guide to some strategies.
See the about tab for an explanation of the league rules.
A bot must be a Python file with two functions: getPlay(gameState) and getSluff(gameState). The gameState parameter receives a GameState class with the following fields:
hand - A Python list of the cards currently in your hand. Cards are represented by a number from 0 to 51. The clubs are 0-12 (with the 2 being 0 and the ace being 12), diamonds are 13-25, spades are 26-38, and hearts are 39-51. An example hand would be [25, 14, 6, 19], containing the ace of diamonds, 3 of diamonds, 8 of clubs, and 8 of diamonds.
legalMoves - The cards in your hand that you can legally play at that point. (Same format.)
lead - An integer representing the player who led or leads this trick. Player 1 is 0, Player 2 is 1, and so on.
playHistory - The cards that have been played (not including sluffed cards) so far this game. This is formatted as a list of lists of cards. Player 1 is the first sublist, Player 2 the second, and so on. Each sublist is only as long as the number of cards that player has played. An example list would be:
[[10],
[12, 14],
[ 0, 17],
[ 6]]
roundPoints - A Python list containing the number of points each player has taken so far this round. For example, if Player 2 has taken 5 points and everyone else has taken no points, it would be [0, 5, 0, 0].
gamePoints - The number of points each player has taken so far this game. (Same format.) This list is not updated until the end of each round.
whichPlayer - Your place in the turn order. (Same format as lead.)
sluffDirection - An integer representing which direction cards are passed this round. 1 is to the player immediately after you in the order, 2 is to the player across from you, and 3 is to the player immediately before you.
sluffedByYou - A list containing the cards you have sluffed so far this game.
sluffedToYou - A list containing the cards that were sluffed to you so far this game. This list is not updated until after all cards have been sluffed.
Both functions must return the index of the card in legalMoves that you intend to play. If legalMoves is [5, 4, 11] and you wish to play the 6 of clubs, you would return 1. If an index not in legalMoves is returned, a random legal move will be selected instead.
You may not import any modules other than numpy, pandas, math, and random. A season has hundreds of thousands of moves, so each move should take no longer than about 30 milliseconds to allow for quick simulation.
The Hearts League simulation code is provided, along with an example roster, schedule, and bot. Run HeartsLeague.py with your bot in the Bots folder and its name in the roster, and view the tables in the Outputs to see the results.
Email the Python file to me at damiensnyder@damiensnyder.com, and if it meets the requirements I will add it to the next applicable event.
Do not redistribute any of my code or its outputs without my written permission.