The function uses the hand evaluation in an expert-defined rule-based betting strategy to compute the three values. The hand evaluation comprises the strength and the potential of the hand; the strength represents the probability of the hand presently being the strongest one and the potential represents the probability of the hand becoming the strongest after future cards have been dealt (see ).
The first version of the PT generation function was a completely new betting strategy that was simpler than Loki-1's betting strategy. Although this function sufficed to show experimentally the advantages of having a non-deterministic betting strategy, it was outperformed by the old one. The main advantage of having a non-deterministic betting strategy is that we allow Loki-2 to randomly choose its action based on a set of probabilities rather than follow the single action returned by Loki-1's betting strategy.
The second attempt to create the PT function was to translate the strong, but rigid, betting strategy of Loki-1 into the PT scheme. A literal translation of the previous betting strategy into the PT function produced pure or deterministic probability triples. A pure PT has the value of the most likely action equal to one and the other two actions equal to zero. Once the PT function mimicked Loki-1's betting strategy, the boundaries between actions were smoothed by applying linear interpolation to create unpredictability.
With Loki-1's betting strategy in PT form, small modifications to the PT function, such as the one described in the previous paragraph, are less time consuming and the consequences of each change can be evaluated independently. By compartmentalizing the expert knowledge in a single routine, the design was improved by standard software engineering concepts. The benefits of the PT generation function are:
To generate the PT for a hand,
the hand value is computed first. The hand value is an estimate of the
probability of winning. This value is then used by a set of rules to
compute the probabilities of folding, calling and raising. Consider
that S() gives the public information about a game, h is a hand,
EHS(h, S()) gives the hand value, and
represents a PT generation function.
An abstract view of a simplistic PT generation function is: