user16626: By a safe advantage, I mean it is easy for the side with the advantage to keep it. Winning the game is extremely likely under normal conditions. Example: KQ vs KN is a very safe advantage.
By an unsafe advantage, I mean it is a complicated position and the side with the advantage can only keep it with very accurate play. If they make even one mistake/inaccurate move, the advantage may be lost and they may even lose the game. Many complicated middle game positions are "unsafe" in this sense.
Does there exist terminologies that describe a "safe advantage" and "unsafe advantage"? Can an engine give a "safety index" of an advantage?

user34079: What you are looking for is the term "sharp". A position that is sharp requires accurate play to maintain the evaluation; there may only be one good move for either side. From there defining this sharpness is hard to do from a first principles basis as what is sharp for you or I may not be for Magnus. That aside here is a free tool you may want to play with. The fritz engine also claims to have its own sharpness evaluator.

16626: <p>By a safe advantage, I mean it is easy for the side with the advantage to keep it. Winning the game is extremely likely under normal conditions. Example: KQ vs KN is a very safe advantage.</p>
<p>By an unsafe advantage, I mean it is a complicated position and the side with the advantage can only keep it with very accurate play. If they make even one mistake/inaccurate move, the advantage may be lost and they may even lose the game. Many complicated middle game positions are &quot;unsafe&quot; in this sense.</p>
<p>Does there exist terminologies that describe a &quot;safe advantage&quot; and &quot;unsafe advantage&quot;? Can an engine give a &quot;safety index&quot; of an advantage?</p>
 34079: <p>What you are looking for is the term &quot;sharp&quot;. A position that is sharp requires accurate play to maintain the evaluation; there may only be one good move for either side. From there defining this sharpness is hard to do from a first principles basis as what is sharp for you or I may not be for Magnus. That aside here is a free <a href="https://chessinsights.org/analysis/" rel="nofollow noreferrer">tool</a> you may want to play with. The <a href="https://en.chessbase.com/post/new-power-fritz-18-the-chess-software-world-champion-2022" rel="nofollow noreferrer">fritz</a> engine also claims to have its own sharpness evaluator.</p>
