I would like to thank everyone who has helped me advance this project (CHA),
with special thanks to:
Pablo-No whose GitHub
got me interested in this problem, for fruitful conversations during the early
stages of this project.
Pooya Farshim, for very fruitful discussions about countless topics, including
chess unwinnability. For all his help and comments on the
research paper about this tool
(which has been published at Fun with Algorithms 2022).
Elena Gutiérrez, for all her support, help and comments on
CHA's research paper.
for providing the hardware used for running CHA over the entire Lichess database.
for very fruitful discussions about chess unwinnability and dead reckoning,
for all his feedback and for sharing with me and letting me include
two original compositions in the
(I am also very thankful to Andrey Frolkin, co-author of one of them.)
Maarten Löffler for all his feedback about the
and for having found a gap in an earlier version of the proof of Lemma 8.
Also for having identified, thanks to a deep understanding of our algorithm,
class of positions
that cannot be handled by our quick routine.
Consequently these artificial positions may fool the full routine when run with
an insufficient search limit.
All the anonymous reviewers of the 11th International Conference on Fun with Algorithms,
for their valuable time, their careful reading of our
and all their comments.
The Stockfish Team, for their amazing
and altruistic chess engine on which CHA relies.
The Lichess Team, for the
database of games used to test this tool
and, of course, for making Lichess possible and for continuing improving it every day!
George Wang, for all his support and interest in this project and for all his feedback.
José María Gutiérrez, for his very careful reading of our
and all his support and feedback.
Ricardo García, for all his support and interest in this project.
for many fruitful and deep conversations about this project and the
And for all his feedback and multiple suggestions.
for his time on
the preliminary version of this tool (D3).
Niklas Fiekas, for
this project in GitHub and for
python-chess, which is amazing
and I have used so many times in the past!
Jesper Nørgaard, for having found and reported the first known
class of positions
that CHA 2.2 could not classify correctly. CHA 2.4 now can!
for reviewing CHA's source code and proposing improvements on memory allocation.
All the Lichess users who have commented on the Lichess Forum, in threads related to