AI Group
Applied Informatics
University of Macedonia, Greece
Contact: nikpapa at gmail dot com

I have received a PhD doctorate from the Department of Applied Informatics, University of Macedonia, under the supervision of Assistant Professor Ioannis Refanidis.

As part of my MSc and PhD, I have developed Palamedes, a program that plays at expert level the backgammon variants Portes, Fevga, Plakoto, Narde and other variants. Palamedes won the gold metal at the latest Backgammon Computer Games Olympiad.

My research interests are: Artificial Intelligence, Game AI, Machine Learning, Reinforcement Learning, Neural Networks.



The aim of the Palamedes project is to determine if it is possible to create expert game AIs for popular backgammon variants using techniques similar to what is used by strong backgammon programs. The project currently supports the Greek Tavli variants (Portes, Plakoto, Fevga) as well as other popular variants like Narde, Nackgammon, Hypergammon, Takhteh and Tapa. Each game’s expert AI is build using neural networks trained by millions of self-play games using advanced reinforcement learning techniques.


Normally backgammon games are played in a 24-point board using 15 checkers or men per side and 2 six-sided dice. This project attempts to extend the popular backgammon games to arbitrary configurations. Games can be played using different board sizes, number of checkers, and number of die sides. Smaller board configurations make the game easier for players and AI algorithms, while larger board configurations make it more challenging.



Papahristou, N., Refanidis, I., Constructing Pin Endgame Databases for the Backgammon Variant Plakoto., 14th International Conference Advances in Computer Games, ACG 2015, Leiden, The Netherlands, LNCS 9525, pp 177-184, 2015 [pdf]


Papahristou, N., Refanidis, I., Opening Statistics and Match Play for Backgammon Games, Proceedings of 8th Hellenic Conference on Artificial Intelligence, SETN 2014, Ioannina, Greece, LNCS 8445, pp 569-582, 2014 [pdf]


Nikolaos Papahristou and Ioannis Refanidis, AnyGammon: Playing Backgammon Variants Using Any Board Size, Entry at the Research and Experimental Festival of the 8th International Conference on the Foundations of Digital Games, FDG 2013, Chania, Crete, May 2013. [pdf]


Papahristou, N., Refanidis, I., On the Design and Training of Bots to Play Backgammon Variants, 8th IFIP WG 12.5 Artificial Intelligence Application and Innovations Conference, AIAI 2012, Halkidiki, Greece, September 27-30, 2012, Proceedings, Part I, Volume 381/2012, pp 78-87, 2012 [pdf]
Papahristou, N., Refanidis, I., Improving Temporal Difference Performance in Backgammon Variants, 13th Advances in Computer Games Conference, ACG 2011, Tilburg, The Netherlands, November 20-22, 2011, LNCS 7168, pp 134-145, 2012. [pdf]


Nikolaos Papahristou, Ioannis Refanidis, Training Neural Networks to Play Backgammon Variants Using Reinforcement Learning, Proceedings of Evogames 2011, EvoApplications 2011, Part I, LNCS 6624, pp. 113-122, 2011 [pdf]

Curriculum Vitae


Date of Birth: 1 Oct 1972
Nationality: Greek
Current Residence: Athens, Greece


2012 Tech Pioneer Award by the PC Magazine Greece.
2008 Greek State Scholarship Foundation (IKY) scholarship awarded (2008).


Greek (native language)
English (Proficiency of English – Cambridge University)


Nov 2010 – Nov 2015 PhD in Applied Informatics from Department of Applied Informatics of University of Macedonia.
Oct 2008 – July 2010 Master’s of Science in Applied Informatics (specialization in Computer Systems) from the Department of Applied Informatics, University of Macedonia (GPA: 9.28/10).
Sep 1992 – July 1998 Bachelor of Science in Automation Engineering from the Department of Automation of Technological Institute of Thessaloniki (GPA: 6.5/10).

Work Experience

Sep 2006 – present Teacher of Informatics in Greek State Schools of Secondary Education.
Oct 1999 – Jul 2006 Software engineer, system administrator in SGA Informatics systems.
Sep 1998 – Sep 1999 Automation engineer in Astron Computers.

2019 © Nikolaos Papahristou