1. b3. It’s not easy to defeat and they’re probably playing it because I they like watching Hikaru play it, so they’re familiar with it too.
Most annoying opening to play against?

Petrov. When Knights and pawns endgames are difficult enough, now amp it up when the whole army is on the board and undeveloped. Feels like trying to guess where a random particle will be. Alekhine because I might face it once in a hundred games and have to remember what the theory is as to not be under developed behind the over extended pawns. They seem to be most popular in bullet as it requires extra thinking from players who dont face them often in other time contols so probably gets good results.
What do you think is the most annoying opening and why? I say london because it's just boring