This repo contains source code for (Li)chess search engine bot's Discord chess engine, and (Li)quid chess engine both are part of the Lise bot code family.

Liquid Search Engine [LISE]

Liquid chess engine tries to replicate human play, self-adjusting according to the opponent's Lichess blitz rating, named Liquid as it adapts to the opponent's rating play meaning plays strong against stronger players, weak against beginner players.

Liquid comes in 4 modes

• Beast [2400+]
• Strong [1900 - 2400]
• Novice [1400 - 1900]
• Beginner [0 - 1400]

Liquid Lichess Ratings

• Blitz 2230
• Bullet 2281
• Rapid 1872
• Classical 1879?

Liquid's helpers

Liquid uses Stockfish's best move to come up with the right one, but according to its mode, it can self-adjust to using Stockfish or its logic.

• Stockfish [running at various depths for various modes] (The Stockfish developers (see AUTHORS file). Stockfish [Computer software]. https://github.com/official-stockfish/Stockfish)
• Negamax algorithm
• frequency-based blunder logic that plays a stockfish or the best move according to eval function and uses random frequency technique to "throw" like a human and mess up but at same time play the best move

Liquid's Eval

• the amount of pieces both sides have
• both kings are attacked
• board space and center space
• look at captures
• look at which pieces are where

UCI Protocol

Liquid uses UCI protocol it supports following commands:

LISE UCI COMMANDS: 

-------------------------------------------------------
isready (check if engine is ready)
level (Change level)
position <FEN_STRING> (get Lise's best move in given FEN)
eval <FEN_STRING> (get Lise's eval in given FEN)
uci (view Lise UCI commands)
quit (Quit the engine)

Running Liquid locally and use it via UCI

git clone LiseChessEngine

cd LiseChessEngine/src

mvn clean

mvn compile

mvn package

java -jar 4.0-SNAPSHOT.jar

Lise Chess Engine

Lise is an effortless engine that runs at low depths and performs a chess engine role in Discord, it's part of the Lichess search engine bot's repo code

Lise mode

• Beginner

Lise's helper

simple negamax method to search for moves at lower depths

Challenge (Li)quid search engine Lise

Please only challenge white side casual/rated

Play Lise Here

(Please note the Lichess bot may be down some days, due to maintaince/resource limit)

Authors

@jalpp