Serious bug #383
Description
Hello developers of Clockwork,
I hope you are doing well today. My name is Tom and I am a normal chess player from Europe. I really like your chess engine called Clockwork because it is free and it plays very fast on my computer. I use it almost every day to practice my openings and to see good moves. Last week I decided to test it against the very famous Stockfish engine because I wanted to see how strong Clockwork is now. I read on the GitHub page that Clockwork is getting better every month with new updates, so I was excited. But then something bad happened. I ran one game of Clockwork against Stockfish and Clockwork lost. It was not a close game. Stockfish won very easily. I think there is a problem in the code and I want to ask you please to fix it.
Let me tell you everything from the beginning so you can understand the full story. First, I downloaded the newest version of Clockwork. I got it from the releases page on GitHub. Then I also downloaded Stockfish 16 because everyone says it is the best engine right now. I put both engines in the same folder on my laptop. My laptop is not very new but it has 16 GB of RAM and an Intel processor. I used Arena chess GUI because it is simple and free. I set the time control to 10 minutes plus 5 seconds increment for each player. That is a normal time for testing I think.
Before I started the game I checked all the settings two times. I made sure that Clockwork uses 4 threads and 512 MB hash table. Stockfish had the same settings. The opening book was off because I wanted to see the real engine play from the start. I clicked "New Game" and chose Clockwork as white and Stockfish as black. The game started with 1. e4. Clockwork played that move fast. Then Stockfish answered 1... e5. Everything looked normal at first.
After about 10 moves I saw that Clockwork was already in trouble. It played some strange moves like moving the knight to a bad square and then it lost a pawn for nothing. I was sitting at my desk and watching the screen and I thought "oh no, this is not good". The evaluation bar went down quickly from +0.5 to -2.0 and then even lower. Clockwork did not find any good plan in the middle game. Stockfish just took more pieces and then it made a nice attack on the king. The game ended after 38 moves with checkmate.
Stockfish did not even use much time. Clockwork spent a lot of time on bad moves and the search was not deep enough I think. I expected Clockwork to at least draw the game or make it very hard for Stockfish.
I tried the same game two more times with different colors and different openings. One time I started with 1. d4 and the same thing happened again. Clockwork lost in 45 moves. The third game was with black and it was even worse, mate in 29 moves. So it is not only one bad game. There is a real problem.
I love Clockwork because it is open source and the community is nice. I even tried to look at the code myself but I do not know programming very well, only a little bit of Python. Maybe the evaluation function is too simple in some positions or the time management is wrong when the position is closed. Or perhaps the null-move pruning is not working good. I do not know. That is your job to find out.
Please can you fix this? I want to run more games and see Clockwork win sometimes. It makes me happy when my favorite engine beats the big ones. Maybe you can add more training data or change some parameters in the next version. Or make a special patch for this bug. I can test it again if you give me a new build.
I am sorry if my English is not perfect. I am B1 level and I learned it in school. But I think you understand what I mean. The important thing is: Clockwork lost to Stockfish and I want it fixed please.
Thank you very much for reading my long message. You do great work with this project and I hope you continue. I will keep using Clockwork every day and I will report more things if I see them.
Best regards,
Tom from Poland