99.9% Accuracy !! ??

Recently purchased the platinum membership for Black Friday on chess.com, and used their analysis on nearly every game.  Maybe the turkey or all the other foods over the holidays, but I have played a roller coaster of games, some being ranked 2000 followed by an 800 game or worse.  I dropped from 1500 level as losses racked up over wins, and noticed my emotional level had "blinded" me in seeing moves.  

Out of the blue, I played a game a few short moves of 12, the Greek? , and got a 99.9 % accuracy game.  It was common moves for the Greek checkmate, bishop sacrifice, knight check, 2 moves of queen for #.  

https://www.chess.com/analysis/game/live/146046698554/analysis?move=23

Another thing I've noticed, the accuracy and game rating seem dependent on the way the other opponent plays.  In the 800 ranked games, both my opponent and I ranked low, in higher rankings, my opponent scores close or higher.  Still think I'm too low of a level to understand the usefulness of this, only I played horrible to I played good to great.