When I was a 1300 or 1400, I played an 1800 in the first round of our city's championship back in the 1970's.
I didn't know Opening Theory, didn't know what my opponent played as Black, so I did a double fianchetto!
This totally befuddled my opponent and I won a miniature! When we went over the game afterwards in the skittles.room, he was gracious while feeling immense disgust. He asked me what kind of opening was that. I told him I just.wanted to take him out of Book.
Losing to someone rated 400 points below you in the 1st round caused him to think he was in bad form, and he withdrew from the tournament.
I have no idea how I did in the tournament. All I remember is the exquisite delight and pleasure of beating my first "A" rated player.as a 400+ point underdog.
In the 1970's?? So you're old, but still cool enough to have a Gru profile picture!
I was playing in a USCF tournament in Chicago. Won my first 2 games and then was paired against the top rated player [a strong master] I had Black.
After about 12 moves he offered a draw!
I thought to myself "Why does he think he is losing??"
After some thought I declined his draw offer.
About 11 moves later I resigned.