Journal
Articles
Why Not This Route? Counterfactual Explanations for Personalized Routing
Chengpeng Hu, Mehrdad Asadi, Paolo Speziali, Hendrik Baier
Frontiers of Computer
Science.
Accepted. 2026
MOMAland: A Set of Benchmarks for Multi-Objective Multi-Agent Reinforcement Learning
Florian Felten, Umut Ucak, Hicham Azmani, Gao Peng, Willem Röpke, Hendrik Baier, Patrick Mannion, Diederik M Roijers, J. K. Terry, El
Ghazali Talbi, Grégoire Danoy, Ann Nowé, Roxana Rădulescu
Journal of Data-centric Machine Learning
Research.
Accepted. 2026
Novelty in Monte Carlo Tree Search
Hendrik Baier, Michael Kaisers
IEEE Transactions on Games, vol. 17, no. 4, pp.
1013–1023.
2025
Language Models Speed Up Local
Search for Finding Programmatic Policies
Quazi Asif Sadmine, Hendrik Baier, Levi H. S. Lelis
Transactions on
Machine Learning
Research.
2024
Value Targets in
Off-policy AlphaZero: a New Greedy Backup
Daniel Willemsen, Hendrik Baier, Michael Kaisers
Neural Computing and
Applications, vol. 34, no. 3, pp.
1801–1814.
2022
The Text-Based Adventure AI
Competition
Tim Atkinson, Hendrik Baier, Tara Copplestone, Sam Devlin, Jerry Swan
IEEE Transactions on
Games, vol. 11, no. 3, pp.
260–266.
2019
Emulating Human Play in a Leading Mobile Card Game
Hendrik Baier, Adam Sattaur, Edward J. Powley, Sam Devlin, Peter I. Cowling, Jeff Rollason
IEEE Transactions on
Games, vol. 11, no. 4,
pp. 386–395.
2019
MCTS-Minimax Hybrids with State Evaluations
Hendrik Baier, Mark H. M. Winands
Journal of Artificial
Intelligence Research, vol. 62, pp.
193–231.
2018
Time Management for Monte Carlo Tree Search
Hendrik Baier, Mark H. M. Winands
IEEE Transactions on
Computational Intelligence and AI in Games, vol. 8, no. 3, pp.
301–314.
2016
MCTS-Minimax Hybrids
Hendrik Baier, Mark H. M. Winands
IEEE Transactions on Computational Intelligence and AI in Games, vol. 7, no. 2, pp.
167–179.
2015
The Power of Forgetting: Improving the Last-Good-Reply Policy in Monte Carlo
Go
Hendrik Baier, Peter Drake
IEEE Transactions on Computational Intelligence and AI in Games, vol. 2, no. 4, pp. 303–309.
2010
Conference
Articles
Scheduling that Speaks: An Interpretable Programmatic Reinforcement Learning Framework
Chengpeng Hu, Yingqian Zhang, Hendrik
Baier
European
Conference on Machine Learning and Principles and Practice of Knowledge Discovery in Databases (ECML PKDD
2026). Accepted.
2026
LogiEx: Integrating Formal Logic and LLMs for Explainable Transit Planning
Ziyan An, Xia Wang, Hendrik Baier, Zirong Chen, Abhishek Dubey, Taylor T. Johnson, Jonathan Sprinkle, Meiyi
Ma
17th ACM/IEEE International Conference on Cyber-Physical
Systems (ICCPS
2026). Accepted.
2026
Explanations for Sequential Decision-Making - An Overview
Hendrik Baier, Mark T. Keane, Sarath Sreedharan, Silvia Tulli, Abhinav
Verma
40th AAAI Conference on Artificial
Intelligence (AAAI 2026), pp.
40948–40953.
2026
InnateCoder: Learning Programmatic Options with Foundation Models
Rubens O. Moraes, Quazi Asif Sadmine, Hendrik Baier, Levi H. S. Lelis
34th International Joint Conference on Artificial Intelligence (IJCAI 2025), pp.
7652–7660.
2025
Algorithm Configuration in Sequential Decision-Making
Luca Begnardi, Bart von Meijenfeldt, Hendrik Baier, Willem van Jaarsveld, Yingqian Zhang
22nd Int. Conf. on the Integration of Constraint Programming, Artificial Intelligence, and
Operations Research (CPAIOR 2025), pp.
86–102.
2025
Enabling MCTS Explainability for Sequential Planning Through Computation Tree Logic
Ziyan An, Hendrik Baier, Abhishek Dubey, Ayan Mukhopadhyay, Meiyi Ma
27th European Conference on Artificial Intelligence (ECAI 2024), pp.
4068–4075.
2024
Deep Reinforcement Learning for Two-sided Online Bipartite Matching in Collaborative Order Picking
Luca Begnardi, Hendrik Baier, Willem van Jaarsveld, Yingqian Zhang
Asian Conference on Machine Learning 2023 (ACML 2023), pp.
121–136.
2023
BRExIt: On Opponent Modelling in Expert
Iteration
Daniel Hernandez, Hendrik Baier, Michael Kaisers
32nd International Joint Conference on Artificial Intelligence (IJCAI 2023), pp.
3795–3802.
2023
Online Planning in POMDPs with Self-Improving
Simulators
Jinke He, Miguel Suau, Hendrik Baier, Michael Kaisers, Frans A. Oliehoek
31st International Joint Conference on Artificial Intelligence (IJCAI 2022), pp. 4628–4634.
2022
ME-MCTS: Online Generalization by Combining Multiple Value Estimators
Hendrik Baier, Michael Kaisers
30th International Joint Conference on Artificial Intelligence (IJCAI 2021), pp.
4032–4038.
2021
Guiding Multiplayer MCTS by
Focusing on Yourself [nominated for best
paper]
Hendrik Baier, Michael Kaisers
2020
IEEE Conference on Games (CoG 2020), pp.
550–557.
2020
Opponent-Pruning Paranoid Search [exceptional paper award]
Hendrik Baier, Michael Kaisers
2020
International Conference on the Foundations of Digital Games (FDG 2020), pp.
10:1–10:7.
2020
Evolutionary MCTS with
Flexible Search Horizon
Hendrik Baier, Peter I. Cowling
14th
AAAI Conference on Artificial Intelligence and Interactive Digital Entertainment (AIIDE 2018), pp.
2–8. 2018
Evolutionary MCTS
for Multi-Action Adversarial Games [nominated for best paper]
Hendrik Baier, Peter I. Cowling
2018
IEEE Conference on Computational Intelligence and Games (CIG 2018), pp.
1–8. 2018
Decentralized Online Planning for Multi-Robot Warehouse Commissioning [nominated for best
paper]
Daniel Claes, Frans Oliehoek, Hendrik Baier, Karl Tuyls
16th
International Conference on Autonomous Agents and Multiagent Systems (AAMAS 2017), pp.
492–500.
2017
Monte-Carlo Tree Search and Minimax Hybrids
Hendrik Baier, Mark H. M. Winands
2013 IEEE Conference on Computational Intelligence and Games (CIG 2013), pp.
129–136.
2013
Beam Monte-Carlo Tree Search
Hendrik Baier, Mark H. M. Winands
2012 IEEE Conference on Computational Intelligence and Games (CIG 2012), pp.
227–233.
2012
Nested Monte-Carlo Tree Search for Online Planning in Large MDPs
Hendrik Baier, Mark H. M. Winands
20th European Conference on Artificial Intelligence (ECAI 2012), pp.
109–114.
2012
Time Management for Monte-Carlo Tree Search in
Go
Hendrik Baier, Mark H. M. Winands
13th International Conference on Advances in Computer Games (ACG 2011), vol. 7168 of LNCS, pp.
39–51.
2012
Active Opening Book Application for Monte-Carlo Tree Search in Go
Hendrik Baier, Mark H. M. Winands
23rd Benelux Conference on Artificial Intelligence (BNAIC 2011), pp.
3–10.
2011
Workshop Articles, Demos, and Extended
Abstracts
Assessing Automatic Concept Extraction for Reinforcement Learning Policies
Chengpeng Hu, Yingqian Zhang, Hendrik Baier
2026 IJCAI-ECAI Workshop on Explainable Artificial Intelligence.
2026
Sequential Decision-Making with Explanatory Actions
Hendrik Baier, Roya Daneshi, Sarath Sreedharan
2026 IJCAI-ECAI Workshop on Explainable Artificial Intelligence.
2026
Command-Space Counterfactual Explanations for Pareto-Conditioned Reinforcement Learning
Joanikij Chulev, Hendrik Baier
2026 IJCAI-ECAI Workshop on Explainable Artificial Intelligence.
2026
LogiEx: Integrating Formal Logic and LLMs for Explainable Transit Planning [Demo]
Ziyan An, Xia Wang, Hendrik Baier, Zirong Chen, Abhishek Dubey, Taylor T. Johnson, Jonathan Sprinkle, Meiyi
Ma
17th ACM/IEEE International Conference on Cyber-Physical
Systems (ICCPS
2026). Accepted.
2026
InnateCoder: Learning Programmatic Options with Foundation Models [Extended Abstract]
Rubens O. Moraes, Quazi A. Sadmine, Hendrik Baier, Levi H. S. Lelis
37th
Benelux Conference on Artificial Intelligence (BNAIC 2025).
2025
Combining LLMs with a Logic-Based Framework to Explain MCTS (Extended Abstract)
Ziyan An, Xia Wang, Hendrik Baier, Zirong Chen, Abhishek Dubey, Taylor T. Johnson, Jonathan Sprinkle, Ayan Mukhopadhyay, Meiyi Ma
24th International Conference on Autonomous Agents and Multiagent Systems (AAMAS 2025), pp.
2405–2407.
2025
Multi-Objective Utility Actor Critic with Utility Critic for Nonlinear Utility Function
Gao Peng, Eric Pauwels, Hendrik Baier
18th European Workshop on Reinforcement Learning (EWRL 2025).
2025
MOMAland: Benchmarking Multi-Objective Multi-Agent Reinforcement Learning
Florian Felten, Umut Ucak, Hicham Azmani, Gao Peng, Willem Röpke, Hendrik Baier, Patrick Mannion, Diederik M Roijers, Jordan K. Terry, El-Ghazali
Talbi, Gregoire Danoy, Ann Nowé, Roxana Radulescu
Multi-Objective Decision Making Workshop at ECAI 2024.
2024
Model-Based Reinforcement Learning in Multi-Objective Environments with a Distributional Critic
Willem Röpke, Diederik M Roijers, Ann Nowé, Roxana Radulescu, Hendrik Baier
Multi-Objective Decision Making Workshop at ECAI 2024.
2024
Decision Making in Non-Stationary Environments with Policy-Augmented Search (extended abstract)
Ava Pettet, Yunuo Zhang, Baiting Luo, Kyle Wray, Hendrik Baier, Aron Laszka, Abhishek Dubey, Ayan Mukhopadhyay
23rd International Conference on Autonomous Agents and Multiagent Systems (AAMAS 2024), pp.
2417–2419.
2024
Hendrik Baier, Michael Kaisers
1st Evolutionary Reinforcement Learning Workshop at GECCO 2021, pp.
1483–1487.
2021
Hendrik Baier, Michael Kaisers
2021 AAAI Workshop on Explainable Agency in AI.
2021
Hendrik Baier, Michael Kaisers
2020 IJCAI-PRICAI Workshop on Explainable Artificial Intelligence.
2020
Value Targets in Off-policy AlphaZero: a New Greedy Backup
Daniel Willemsen, Hendrik Baier, Michael Kaisers
Adaptive and Learning Agents Workshop at AAMAS 2020 (ALA 2020).
2020
MCTS-Minimax Hybrids with State Evaluations (extended abstract)
Hendrik Baier, Mark H. M. Winands
27th International Joint Conference on Artificial Intelligence (IJCAI 2018), pp.
5548–5552.
2018
A Rollout-Based
Search Algorithm Unifying MCTS and Alpha-Beta
Hendrik Baier
Computer Games: Fifth Workshop on Computer Games (CGW 2016), pp.
57–70.
2016
Monte-Carlo Tree Search and Minimax Hybrids with Heuristic Evaluation
Functions
Hendrik Baier, Mark H. M. Winands
Computer Games: Third Workshop on Computer Games (CGW 2014), vol. 504 of
CCIS, pp.
45–63.
2014
Nested Monte-Carlo Tree Search for Online Planning in Large MDPs (extended abstract)
Hendrik Baier, Mark H. M. Winands
24th Benelux Conference on Artificial Intelligence (BNAIC 2012), pp.
273–274.
2012
Publications without Peer Review & Theses
Explainable AI for Sequential
Decision Making (Dagstuhl Seminar 24372)
Hendrik Baier, Mark T. Keane, Sarath Sreedharan, Silvia Tulli, Abhinav Verma, Stylianos L. Vasileiou
Dagstuhl Reports 14.9, pp.
67–103. Schloss
Dagstuhl – Leibniz-Zentrum für Informatik.
2025
Monte-Carlo Tree Search Enhancements for One-Player and Two-Player Domains
Hendrik Baier
Ph.D. thesis. Department of Knowledge Engineering, Maastricht University, Maastricht, The Netherlands.
2015
Adaptive Playout Policies
for Monte Carlo Go
Hendrik Baier
Master's thesis. Institute of Cognitive Science, Osnabrück University, Osnabrück, Germany.
2010