SearchAlgorithm

dicechess.engine.search.SearchAlgorithm

Contract for bot strategies in the Dice Chess Engine.

Implementations receive the current dicechess.engine.domain.GameState and the multiset of available dice rolls, then return the chosen full-turn path wrapped in a ScoredSequence, or None when the position has no legal moves (the active player must pass).

Implementations are expected to be thread-safe singletons (e.g., Scala object).

==Resignation== No shouldResign hook exists on SearchAlgorithm by design. Resignation is an operational decision handled by the bot runtime / host application layer rather than the search strategy.

Attributes

Source
SearchAlgorithm.scala
Graph
Supertypes
class Object
trait Matchable
class Any
Known subtypes

Members list

Value members

Abstract methods

def findBestMove(state: GameState): Option[ScoredSequence]

Finds and returns the best full-turn path according to this strategy.

Finds and returns the best full-turn path according to this strategy.

Value parameters

state

the current dicechess.engine.domain.GameState; state.activeColor identifies the side to move

Attributes

Returns

Some([[ScoredSequence]]) when at least one legal path exists; None when the player must pass

Source
SearchAlgorithm.scala

Concrete methods

protected def estimateWinProbability(state: GameState): Double

Estimates the winning probability in [0.0, 1.0] for the side to move. Convenience over winProbability for offer decisions, where the deciding side is the active colour; do not override it, override winProbability.

Estimates the winning probability in [0.0, 1.0] for the side to move. Convenience over winProbability for offer decisions, where the deciding side is the active colour; do not override it, override winProbability.

Attributes

Source
SearchAlgorithm.scala
def findBestMove(state: GameState, random: Random): Option[ScoredSequence]

Finds the best full-turn path, drawing any randomness (e.g. tie-breaking among equally-valued turns) from the supplied random. Lets a caller make a whole game reproducible from one seed — most importantly the bot arena, which otherwise gets a fresh unseeded Random per move and so is non-deterministic.

Finds the best full-turn path, drawing any randomness (e.g. tie-breaking among equally-valued turns) from the supplied random. Lets a caller make a whole game reproducible from one seed — most importantly the bot arena, which otherwise gets a fresh unseeded Random per move and so is non-deterministic.

The default ignores random and delegates to the no-arg findBestMove; randomised strategies override it to route their tie-breaking through the given source.

Attributes

Source
SearchAlgorithm.scala
def shouldAcceptDouble(state: GameState, currentStake: Int, responder: Color): Boolean

Determines whether the bot should accept (Take) or decline (Drop) a double from the opponent, evaluated from the perspective of responder.

Determines whether the bot should accept (Take) or decline (Drop) a double from the opponent, evaluated from the perspective of responder.

This is the single policy point for the take/drop decision: strategies that want their own threshold or estimator override this overload. The two-argument form below only delegates here, so a policy written against it is bypassed whenever a caller names the responder explicitly (which every caller holding a doubleDecision state must, see the hazard note there).

Value parameters

currentStake

the proposed double stake (e.g. 2, 4...)

responder

the colour of the player responding to the double offer

state

current game state (dice pool is empty); its active colour is the side to move, which in a double decision is the offerer, not the responder

Attributes

Returns

true to accept the double (Take), false to resign the current stake (Drop)

Source
SearchAlgorithm.scala
def shouldAcceptDouble(state: GameState, currentStake: Int): Boolean

Determines whether the bot should accept (Take) or decline (Drop) a double from the opponent, taking the side to move as the responder. Kept for source and binary compatibility; it delegates to the three-argument overload.

Determines whether the bot should accept (Take) or decline (Drop) a double from the opponent, taking the side to move as the responder. Kept for source and binary compatibility; it delegates to the three-argument overload.

Value parameters

currentStake

the proposed double stake (e.g. 2, 4...)

state

current game state (dice pool is empty)

Attributes

Returns

true to accept the double (Take), false to resign the current stake (Drop)

Note

Perspective hazard: this overload evaluates the win probability of state.activeColor. In a double decision state, state.activeColor is the player who offered the double, NOT the responder, so a caller that feeds the delivered position here asks whether the offerer should take. Callers must prefer shouldAcceptDouble(state, currentStake, responder); strategies must override that overload, not this one.

Source
SearchAlgorithm.scala
def shouldAcceptDraw(state: GameState): Boolean

Determines whether the bot should accept a draw offered by the opponent.

Determines whether the bot should accept a draw offered by the opponent.

Value parameters

state

current game state

Attributes

Returns

true to accept the draw

Source
SearchAlgorithm.scala
def shouldOfferDouble(state: GameState, currentStake: Int): Boolean

Determines whether the bot should offer a double before its dice roll.

Determines whether the bot should offer a double before its dice roll.

Value parameters

currentStake

the current stake of the game

state

current game state (dice pool is empty)

Attributes

Returns

true to offer a double, false otherwise

Source
SearchAlgorithm.scala
def shouldOfferDraw(state: GameState): Boolean

Determines whether the bot should offer a draw in the current position.

Determines whether the bot should offer a draw in the current position.

Value parameters

state

current game state

Attributes

Returns

true to offer a draw

Source
SearchAlgorithm.scala
protected def winProbability(state: GameState, color: Color): Double

Estimates the winning probability in [0.0, 1.0] of color, whichever side is to move.

Estimates the winning probability in [0.0, 1.0] of color, whichever side is to move.

This is the estimator hook: a strategy with its own equity model (for example a Monte-Carlo rollout) overrides this method, so that both the offer decision (active colour) and the take/drop decision (responder colour) see the same estimate. The default maps the centipawn evaluation to a probability with a logistic sigmoid.

Attributes

Source
SearchAlgorithm.scala