This is mine and microbundle's attempt at Sebastian Lague's chess coding challenge.
We did not partake in the original challenge, but had a go at it without peeking at other people's submission.
The bot uses basic alpha-beta pruning and an evaluation based on counting material and giving slight preference to advanced pawns, pieces in the centre and a safe king. We also implented a basic version of quiescence search - once the original depth is hit, we search captures and checks only for a few more moves. One of our bots greatest challenges proved to be time management. It seems our DepthDecider function is not smart enough at deciding how far to look when.
Of course, all the code relevant to the challenge is contained in MyBot.cs. However, we also modified some of the UI code to allow adding more EvilBots. Further, after MyBot chooses a move, the UI figures out its preferred line and displays it in the console.
We also added some of the bots who partook in the original challenge to our set of evil bots. All the work on these is of course due to the respective authors, we only modified the namespaces to make them available as bots to play against.