A Polynomial-Time Algorithm for 1/3-Approximate Nash Equilibria in Bimatrix Games

Authors Argyrios Deligkas, Michail Fasoulakis, Evangelos Markakis



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Author Details

Argyrios Deligkas
  • Royal Holloway, University of London, Egham, UK
Michail Fasoulakis
  • Foundation for Research and Technology-Hellas (FORTH), Heraklion, Greece
  • Athens University of Economics and Business, Greece
Evangelos Markakis
  • Athens University of Economics and Business, Greece

Acknowledgements

The authors would like to thank Marcin Jurdzi{ń}ski for some initial discussions on the Tsaknakis-Spirakis algorithm.

Cite AsGet BibTex

Argyrios Deligkas, Michail Fasoulakis, and Evangelos Markakis. A Polynomial-Time Algorithm for 1/3-Approximate Nash Equilibria in Bimatrix Games. In 30th Annual European Symposium on Algorithms (ESA 2022). Leibniz International Proceedings in Informatics (LIPIcs), Volume 244, pp. 41:1-41:14, Schloss Dagstuhl – Leibniz-Zentrum für Informatik (2022)
https://doi.org/10.4230/LIPIcs.ESA.2022.41

Abstract

Since the celebrated PPAD-completeness result for Nash equilibria in bimatrix games, a long line of research has focused on polynomial-time algorithms that compute ε-approximate Nash equilibria. Finding the best possible approximation guarantee that we can have in polynomial time has been a fundamental and non-trivial pursuit on settling the complexity of approximate equilibria. Despite a significant amount of effort, the algorithm of Tsaknakis and Spirakis [Tsaknakis and Spirakis, 2008], with an approximation guarantee of (0.3393+δ), remains the state of the art over the last 15 years. In this paper, we propose a new refinement of the Tsaknakis-Spirakis algorithm, resulting in a polynomial-time algorithm that computes a (1/3+δ)-Nash equilibrium, for any constant δ > 0. The main idea of our approach is to go beyond the use of convex combinations of primal and dual strategies, as defined in the optimization framework of [Tsaknakis and Spirakis, 2008], and enrich the pool of strategies from which we build the strategy profiles that we output in certain bottleneck cases of the algorithm.

Subject Classification

ACM Subject Classification
  • Theory of computation → Exact and approximate computation of equilibria
Keywords
  • bimatrix games
  • approximate Nash equilibria

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References

  1. Bharat Adsul, Jugal Garg, Ruta Mehta, and Milind Sohoni. Rank-1 bimatrix games: a homeomorphism and a polynomial time algorithm. In Proceedings of STOC, pages 195-204, 2011. Google Scholar
  2. Per Austrin, Mark Braverman, and Eden Chlamtáč. Inapproximability of np-complete variants of Nash equilibrium. In Approximation, Randomization, and Combinatorial Optimization. Algorithms and Techniques, pages 13-25. Springer, 2011. Google Scholar
  3. Yakov Babichenko, Siddharth Barman, and Ron Peretz. Empirical distribution of equilibrium play and its testing application. Math. Oper. Res., 42(1):15-29, 2017. Google Scholar
  4. Imre Bárány, Santosh Vempala, and Adrian Vetta. Nash equilibria in random games. Random Structures & Algorithms, 31(4):391-405, 2007. Google Scholar
  5. Siddharth Barman. Approximating Nash equilibria and dense subgraphs via an approximate version of Carathéodory’s theorem. SIAM J. Comput., 47(3):960-981, 2018. Google Scholar
  6. Shant Boodaghians, Joshua Brakensiek, Samuel B. Hopkins, and Aviad Rubinstein. Smoothed complexity of 2-player Nash equilibria. In Proceedings of FOCS, pages 271-282, 2020. Google Scholar
  7. Hartwig Bosse, Jaroslaw Byrka, and Evangelos Markakis. New algorithms for approximate Nash equilibria in bimatrix games. Theoretical Computer Science, 411(1):164-173, 2010. Google Scholar
  8. Mark Braverman, Young Kun-Ko, and Omri Weinstein. Approximating the best Nash equilibrium in n^o^(log n)-time breaks the exponential time hypothesis. In Proceedings of SODA, pages 970-982. SIAM, 2015. Google Scholar
  9. Xi Chen, Xiaotie Deng, and Shang-Hua Teng. Sparse games are hard. In Proceedings of WINE, pages 262-273, 2006. Google Scholar
  10. Xi Chen, Xiaotie Deng, and Shang-Hua Teng. Settling the complexity of computing two-player Nash equilibria. Journal of the ACM, 56(3), 2009. Google Scholar
  11. Xi Chen, Shang-Hua Teng, and Paul Valiant. The approximation complexity of win-lose games. In Proceedings of SODA, volume 7, pages 159-168, 2007. Google Scholar
  12. Zhaohua Chen, Xiaotie Deng, Wenhan Huang, Hanyu Li, and Yuhao Li. On tightness of the Tsaknakis-Spirakis algorithm for approximate Nash equilibrium. In Proceedings of SAGT, volume 12885, pages 97-111, 2021. Google Scholar
  13. Bruno Codenotti and Daniel Štefankovič. On the computational complexity of Nash equilibria for (0,1) bimatrix games. Information Processing Letters, 94(3):145-150, 2005. Google Scholar
  14. Artur Czumaj, Argyrios Deligkas, Michail Fasoulakis, John Fearnley, Marcin Jurdziński, and Rahul Savani. Distributed methods for computing approximate equilibria. Algorithmica, 81(3):1205-1231, 2019. Google Scholar
  15. Artur Czumaj, Michail Fasoulakis, and Marcin Jurdziński. Approximate well-supported Nash equilibria in symmetric bimatrix games. In Proceedings of SAGT, volume 8768, pages 244-254, 2014. Google Scholar
  16. Constantinos Daskalakis, Paul W. Goldberg, and Christos H. Papadimitriou. The complexity of computing a Nash equilibrium. In Proceedings of STOC, pages 71-78, 2006. Google Scholar
  17. Constantinos Daskalakis, Aranyak Mehta, and Christos Papadimitriou. Progress in approximate Nash equilibria. In Proceedings of EC, pages 355-358, 2007. Google Scholar
  18. Constantinos Daskalakis, Aranyak Mehta, and Christos Papadimitriou. A note on approximate Nash equilibria. Theoretical Computer Science, 410(17):1581-1588, 2009. Google Scholar
  19. Argyrios Deligkas, John Fearnley, Themistoklis Melissourgos, and Paul G. Spirakis. Approximating the existential theory of the reals. J. Comput. Syst. Sci., 125:106-128, 2022. URL: https://doi.org/10.1016/j.jcss.2021.11.002.
  20. Argyrios Deligkas, John Fearnley, and Rahul Savani. Inapproximability results for constrained approximate Nash equilibria. Inf. Comput., 262:40-56, 2018. Google Scholar
  21. John Fearnley, Paul W. Goldberg, Rahul Savani, and Troels Bjerre Sørensen. Approximate well-supported Nash equilibria below two-thirds. Algorithmica, 76(2):297-319, 2016. Google Scholar
  22. Ravi Kannan and Thorsten Theobald. Games of fixed rank: A hierarchy of bimatrix games. Economic Theory, 42(1):157-173, 2010. Google Scholar
  23. Spyros C. Kontogiannis, Panagiota N. Panagopoulou, and Paul G. Spirakis. Polynomial algorithms for approximating Nash equilibria of bimatrix games. In Proceedings of WINE, pages 286-296, 2006. Google Scholar
  24. Spyros C. Kontogiannis and Paul G. Spirakis. Well supported approximate equilibria in bimatrix games. Algorithmica, 57(4):653-667, 2010. Google Scholar
  25. Spyros C. Kontogiannis and Paul G. Spirakis. Approximability of symmetric bimatrix games and related experiments. In Proceedings of SEA, volume 6630, pages 1-20, 2011. Google Scholar
  26. Pravesh K. Kothari and Ruta Mehta. Sum-of-squares meets Nash: lower bounds for finding any equilibrium. In Proceedings of STOC, pages 1241-1248. ACM, 2018. Google Scholar
  27. Richard Lipton, Evangelos Markakis, and Aranyak Mehta. Playing large games using simple strategies. In Proceedings of EC, pages 36-41, 2003. Google Scholar
  28. Zhengyang Liu and Ying Sheng. On the approximation of Nash equilibria in sparse win-lose games. In Proceedings of AAAI, volume 32(1), 2018. Google Scholar
  29. Andrew McLennan and Rabee Tourky. Imitation games and computation. Games and Economic Behavior, 70(1):4-11, 2010. Google Scholar
  30. Andrew McLennan and Rabee Tourky. Simple complexity from imitation games. Games and Economic Behavior, 68(2):683-688, 2010. Google Scholar
  31. Ruta Mehta. Constant rank two-player games are PPAD-hard. SIAM J. Comput., 47(5):1858-1887, 2018. Google Scholar
  32. Aniket Murhekar and Ruta Mehta. Approximate Nash equilibria of imitation games: Algorithms and complexity. In Proceedings of AAMAS, pages 887-894, 2020. Google Scholar
  33. John Nash. Non-cooperative games. Annals of Mathematics, 54(2):286-295, 1951. Google Scholar
  34. Panagiota N. Panagopoulou and Paul G. Spirakis. Random bimatrix games are asymptotically easy to solve (a simple proof). Theory of Computing Systems, 54(3):479-490, 2014. Google Scholar
  35. Aviad Rubinstein. Settling the complexity of computing approximate two-player Nash equilibria. In Proceedings of FOCS, pages 258-265, 2016. Google Scholar
  36. Haralambos Tsaknakis and Paul G. Spirakis. An optimization approach for approximate Nash equilibria. Internet Mathematics, 5(4):365-382, 2008. Google Scholar
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