How I invented Puzzle Rush 10 years before Chess.com released it.
I t was in 2008 when I had finished my chess server WebChess X using open source code WebChess. I opened my chess server and found it was thriving but had a problem with some users cheating. I spent a few months in mid-2008 racking my brain as to how to solve the problem. I eventually came up with an idea. Why not create a test which randomly quizzes users with chess puzzles but make it time constrained and rated so I could validate that the ELO of the user was still consistent with the results they were getting. So I wrote the code in PHP utilising my database of over 10 million chess positions. I also used some open source code called LT PGN VIEWER by Lutz Tautenhahn which had a guess-the-move app, problem board script. The app recognises FEN strings from pgn files of game fragments and matches the move played with the move string loaded. The app I built was simple it randomly selected a position and asked the user to play the winning move. It had to be just that move because their