Well, you can make chess engines give you a numeric evaluation for several possible moves. These are typically tuned so that the value of a pawn is around 1 point. A grandmaster 1 or 2 points ahead can routinely convert to a won game, assuming he doesn&#x27;t blunder.<p>So if the best move has an evaluation of +0.05 and the second best has -0.02 , the difference is probably a very subtle positional improvement (and the first move may not in fact be better; chess programs aren&#x27;t perfect). If the best is +3.12 and the second is -0.02, and you can&#x27;t see why, there&#x27;s a concrete material tactic you&#x27;re missing (or, less likely, a major, obvious positional devastation).<p>But, it can&#x27;t tell you <i>what</i> you&#x27;re missing, just the magnitude of the difference.