A chess engine is a computer or a program that can analyze a position or game. Many players believe that a computer is incapable of making a mistake and whatever evaluation an engine makes should be taken with blind faith.
But as Bobby Fischer once said, “This is the start (of an analysis)”.
Below is such a discussion between an engine and myself.
Chess.com, July 22 2018
1.e4 d5 2.exd5 Qxd5 3.Nf3 (I’ve been experimenting this move for a couple of years. It certainly takes Black out of book and Black has many chances to go wrong in the opening. Like in this game.) 3…Nf6 (This move is very reasonable. It is safe and fits into many Black plans. It is only later when Black forgets why he played this move and apparently forgets about development. By the way, two other common moves are 3…Qe6 and 3…Bg4 are not a good as the text move.) 4.d4 Qa5+ 5.Bd2 Qb6 6.c3 [The engine at chess.com said this was an error and gives the better 6.Na3 c5 (this is because 6…Na3 Qxb2?? loses to 7.Nc4 Qb5 8.Nd6+ – my analysis) 7.Be3 Qa5+ 8.Bd2 Qb6 9.dxc5 Qxc5 10.Be3 Qa5+] 6…Qxb2 7.Qb3 Qxa1 8.Bc4 b6?! (This is too slow. Black has some compensation for his lack of development – the extra rook. He must quickly catch up on his development to secure his advantage. Better is 8… e6. I didn’t need a computer to tell me this! This move would limit the movement of White’s pieces and allows his bishop to move out.)
9.O-O (Again the chess.com computer suggests another move, giving 9.Bxf7+ Kd8 10.O-O Nc6 11.Na3 Na5 12.Qc2 Qxf1+ 13.Kxf1 e6. I saw at least part of this but I wanted to safeguard my own king and keep the Black’s queen isolated in the corner.) 9…Be6?? (Blunder says the computer and I agree. Black still has 9… e6.) 10.Bxe6! fxe6 11.Na3 1-0 (Black resigned. He could of course play 11…Qxf1+ 12.Kxf1 but his lack of development is still a major problem and White’s queen is now in charge.)