Quantitative Rule-Based Strategy modeling in Classic Indian Rummy: A Metric Optimization Approach
Purushottam Saha, Avirup Chakraborty, Sourish Sarkar, Subhamoy Maitra, Diganta Mukherjee, Tridib Mukherjee
TL;DR
The paper addresses strategic play in the 13-card Classic Indian Rummy under imperfect information by introducing MinDist, a distance-based hand metric that complements the traditional MinScore. It develops a tractable rule-based framework using dynamic programming and bitmask representations, augmented by a Super Joker concept to handle unobserved cards, and augments strategies with simple opponent modeling. Empirical evaluation in a two-player zero-sum setting demonstrates that MinDist-based agents—especially when combined with opponent modeling—achieve statistically significant gains over MinScore-based and random baselines, with a clear skill gradient. The work provides an interpretable, formal baseline for algorithmic Rummy strategy design and highlights avenues for dynamic, belief-aware extensions and learning-based integration.
Abstract
The 13-card variant of Classic Indian Rummy is a sequential game of incomplete information that requires probabilistic reasoning and combinatorial decision-making. This paper proposes a rule-based framework for strategic play, driven by a new hand-evaluation metric termed MinDist. The metric modifies the MinScore metric by quantifying the edit distance between a hand and the nearest valid configuration, thereby capturing structural proximity to completion. We design a computationally efficient algorithm derived from the MinScore algorithm, leveraging dynamic pruning and pattern caching to exactly calculate this metric during play. Opponent hand-modeling is also incorporated within a two-player zero-sum simulation framework, and the resulting strategies are evaluated using statistical hypothesis testing. Empirical results show significant improvement in win rates for MinDist-based agents over traditional heuristics, providing a formal and interpretable step toward algorithmic Rummy strategy design.
