Engines... anyone who uses chess programs should know: without this small file the money spent on buying the program is worth nothing, you can find a lot of information on this subject, but I would like to put here my humble knowledge, which is worth considering. The basis of the engine is its code (i.e. structure), which is constantly improved by programmers, currently there are three engines worth knowing: KOMODO - STOCKFISH - Lc0.. each of them shows different possibilities during the game or analysis of the position. Currently there are engines advertised graphically etc. in the clash with these engines they are worthless. The engines "PREDATOR - SOLIDOR" are based on Stockfish code, they have its power = in the code I have placed several options that significantly improve their capabilities, e.g. direct reading of base tables, ctg books and bin books... where the engine automatically chooses the best moves, which leads to a quick solution of the positional problem, ending the game.