My opponent in this OTB Rapid Chess game became a USCF Life Master. I do not recall if he was yet a LM at the time that this chess game was played. This is one of three losses that I have to Corey Acor and my only loss to him with the black pieces.
My opening play with the Black side of the Closed Sicilian Defense may not have been that accurate, but I lost because I failed to realize that my King was in check and thus I tried to make an illegal move with my Rook on my move number 19. The only legal move with that Rook would lose the exchange so I resigned.
The rules do not require my opponent to tell me when my King is in check, but I usually will tell my opponents as a courtesy. Corey did not tell me that my King was in check until after I tried to make an illegal Rook move! Still, I consider Corey Acor to be a gentleman as well as a strong chess player.
I had lost to a master in Round 1 who was visiting from England. I won rounds 2 and 3 and then lost to this master in the final round. That gave me an even score against a fairly strong field for me.
Unfortunately, playing like a patzer every time that I faced Corey Acor made me look like a patzer to him! If Corey had not watched some of my chess games with other strong players he could have concluded that I barely know how to move the pieces! Sometimes, I rise to the level of my competition. At other times, I freak out and play like a beginner! With Corey Acor, the freak out factor kicked in.