The Pokeit pre-flop prototype is available for download. You input the game state, your hole cards, and the action during the hand, and the Excel based tool gives you a 2-way equity estimate of your hand against each opponent’s hand range.

Hand range estimates are derived using a multinomial logit regression model. The general idea is that the model takes the input variables of game state and opponent action and then tells you the conditional probability that your opponent holds each of the 169 possible hands pre-flop. Each component of your opponent’s hand range distribution has an associated showdown equity value against your hand. To derive the estimated equity of your hand against the distribution, we multiply the probability of your opponent holding each hand, by the showdown equity, and sum the whole thing together.

The input variables of the model include:

♦ Player action on each pre-flop ‘round’ of betting (call/check or raise)
♦ Action behind the player (call, raise, 3-bet, etc.)
♦ A variable that combines position with # of players at the table
♦ Amount bet on each pre-flop ‘round’
♦ An interaction between player action and action behind
♦ An interaction between player action and position/# players
♦ An interaction between player action and amount bet

The data used to produce these estimates comes from a 181,007 hands worth of 6-max NL-Hold’em on PokerStars with limits ranging from $0.50-$1.00 NL to $3.00-$6.00 NL. The analysis is completely derived from the revealed hands of my friend Joe, who was kind enough to ship me his PokerTracker database. As you’ll notice when you test it out, Joe is pretty TAG. Some of his stats are vpip = 0.18, pf_raise = 0.12, wwsf = 0.43, and total_af = 2.77. Because the statistical model is based off of just one player, the prototype is somewhat impractical for in-game use. It should however give you an idea of what we have in store.

Just a few notes about the functionality of the Excel workbook:

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