Chess engine

[4] In December 1991, Computer-schach & Spiele referred to Chessbase's recently released Fritz as a 'Schach-motor,' the German translation for 'chess engine.

He wanted to focus on the chess playing part rather than the graphics, and so asked Tim Mann how he could get Junior to communicate with Winboard.

Common Winboard engines would include Crafty, ProDeo (based on Rebel), Chenard, Zarkov and Phalanx.

In 2000, Stefan Meyer-Kahlen and Franz Huber released the Universal Chess Interface, a more detailed protocol that introduced a wider set of features.

Most of the top engines are UCI these days: Stockfish, Komodo, Leela Chess Zero, Houdini, Fritz 15-16, Rybka, Shredder, Fruit, Critter, Ivanhoe and Ruffian.

[9] A more longstanding engine protocol has been used by the Dutch company, Lokasoft,[10] which eventually took over the marketing of Ed Schröder's Rebel.

This is partly due to the increase in processing power that enables calculations to be made to ever greater depths in a given time.

In addition, programming techniques have improved, enabling the engines to be more selective in the lines that they analyze and to acquire a better positional understanding.

Many engines use permanent brain (continuing to calculate during the opponent's turn) as a method to increase their strength.

In 2013, the developers of the Stockfish chess playing program started using distributed computing to make improvements in the software code.

[13][14][15] As of June 2017[update], a total of more than 745 years of CPU time has been used to play more than 485 million chess games, with the results being used to make small and incremental improvements to the chess-playing software.

[citation needed] By the late 1990s, the top engines had become so strong that few players stood a chance of winning a game against them.

To give players more of a chance, engines began to include settings to adjust or limit their strength.

Engines which have a uci_elo parameter include Houdini, Fritz 15–16, Rybka, Shredder, Hiarcs, Junior, Zappa, and Sjeng.

In fact, the number of games that need to be played between fairly evenly matched engines, in order to achieve significance, runs into the thousands and is, therefore, impractical within the framework of a tournament.

However, after the rise of volunteer distributed computing projects such as Leela Chess Zero and Stockfish and testing frameworks such as FishTest and OpenBench in the late 2010s, free and open source programs have largely displaced commercial programs as the strongest engines in tournaments.

Except for some man versus machine games which the SSDF had organized many years ago (when engines were far from today's strength), there is no calibration between any of these rating lists and player pools.

Although very strong and open source, there are allegations from commercial software interests that they were derived from a disassembled binary of Rybka.

The "World Team" included the participation of over 50,000 people from more than 75 countries, deciding their moves by plurality vote.

The sheer number of ideas, the complexity, and the contribution it has made to chess make it the most important game ever played.

ChessV and Fairy-Max, for example, are both capable of playing variants on a chessboard up to 12×8 in size, such as Capablanca Chess (10×8 board).

Convekta's Chess Assistant and Lokasoft's ChessPartner also added the ability to import Winboard and UCI engines into their products.