backscattering.de

2025

Adapting nnue-pytorch's binary position format for Lichess — Technical update for lichess.org
Optimizing Lichess's tablebase server — Technial update for lichess.org, significantly improving tail latencies for tablebase requests

Comparing the quality of backwards-analysis strategies — Experiments to be considered for lichess.org's distributed chess game analysis
Found and filed RUSTSEC-2023-0016.

Announcing the Personal Opening Explorer — Coauthored blog post including some technical details about the new chess opening database
T. Ahlbrecht and J. Dix and N. Fiekas and T. Krausburg: The 15th Multi-Agent Programming Contest — Assemble with Care. Springer, Cham, 2021.
Stockfish 14 on Lichess
Stockfish 13 NNUE on Lichess — Using WASM SIMD for efficient evaluation of neural networks
Hosting a copy of the Universal chess interface (UCI) protocol speficiation
Found and filed RUSTSEC-2021-0004, RUSTSEC-2021-0013, and RUSTSEC-2021-0089.

Lichess End of Year Update 2020 — Coauthored blog post including how we dealt with the influx of players during the pandemic
Stockfish 12 on Lichess — Blog post about queuing improvements for chess game analysis on lichess.org
The Hashtable Packing Problem is strongly NP-complete
Proposal for ISAmI doctoral consortium, plan to build an asynchronous AgentSpeak interpreter: Time in Multi-Agent Systems (pdf, pre copy-edit)

Lichess End of Year Update 2019 — Coauthored blog post including technical changes
Pure CSS rounding for crisp chessboard images
Chess in Rust: Vocabulary
T. Ahlbrecht and J. Dix and N. Fiekas and T. Krausburg: The Multi-Agent Contest 2019 — Agents Assemble — Block by Block to Victory. Springer, 2020.

7-piece Syzygy endgame tablebases are complete — Blog post about the 7-piece chess endgame tablebases on lichess.org
Developer update: 275% improved game compression — Blog post about chess game compression on lichess.org
No bishop magics with fixed shift 8 — Talkchess post about Magic bitboards
Finding Hash Functions for Bitboard Based Move Generation (pdf) — My master's thesis, here uploaded with minor corrections
T. Ahlbrecht and J. Dix and N. Fiekas: The Multi-Agent Contest 2018 — Agents Teaming Up in an Urban Environment. Springer, 2020.

T. Ahlbrecht and J. Dix and N. Fiekas: Special Issue on Multi-Agent Contest 2017. Annals of Mathematics and Artificial Intelligence, Volume 84, Springer, 2018. (pdf, pre copy-edit)
T. Ahlbrecht, J. Dix, N. Fiekas. Scalable Multi-agent Simulation based on MapReduce in Multi-Agent Systems and Agreement Technologies. EUMAS 2016. Lecture Notes in Computer Science, Vol. 10207, pp. 364–374. Springer, 2016. (revised pdf)
D. Honsel, N. Fiekas, V. Herbold, M. Welter, T. Ahlbrecht, S. Waak, J. Dix, J. Grabowski. Simulating Software Refactorings based on Graph Transformations. Post proceedings of the SimScience Workshop 2017.

T. Ahlbrecht and J. Dix and N. Fiekas: Special Issue on Multi-Agent Contest 2016 - Agents in the City. IJAOSE. International Journal of Agent-Oriented Software Engineering, Volume 6 No. 1, Inderscience, 2018. (pdf, draft)
T. Ahlbrecht, J. Dix, N. Fiekas, M. Köster, P. Kraus, J. P. Müller. An architecture for scalable simulation of systems of cognitive agents. International Journal of Agent-Oriented Software Engineering, Vol. 5, No. 2/3, pp. 232–265. Inderscience 2016.
T. Ahlbrecht, J. Dix, N. Fiekas, J. Grabowski, V. Herbold, D. Honsel, S. Waack, M. Welter. Agent-Based Simulation for Software Development Processes in Multi-Agent Systems and Agreement Technologies. EUMAS 2016. Lecture Notes in Computer Science, Vol. 10207, pp. 333–340. Springer, 2016.
Suicide chess tablebases (stalemated player wins) — Talkchess discussion leading to generation of 6 piece Syzygy tablebases for Atomic chess, Suicide chess and Giveaway.
Guest post on chessprogramming.net about python‑chess