Recently I had a very interesting experience playing in the Pan-American Team Championship in Brazil. To set the stage for the most interesting moment in the tournament, first have a look at my first game:
Definitely one of my better games in recent memory. I felt I clearly outplayed and took down a very capable 2600 player without much trouble, gaining an advantage out of the opening and playing very accurately to increase it to a decisive one within 30 moves. However, the main thing to note is the opening choice. I'm not much of a 1.e4 player, and I went right into the mainline Najdorf with opposite side castling. I had definitely done my due diligence on this line, and I have a fair amount of experience in these positions and structures from the black side, but still one does not need to be a genius to surmise that I have done a lot less work on this line than I have in my main 1. d4 repertoire, and that playing right into the Najdorf would be very risky and could go badly wrong if my opponent had some new idea or specific preparation in mind. However, I felt that the risks were worth it, and I went on to win a really good game, the only decisive one in our round 1 match against the top-seeded Cuba. However, what is really interesting is my next game:
Look familiar? Well, it is. It's very rare to get the exact same opening 2 games in row. But I had faith in the analysis I had done, and went right back into the trendy but unusual 8. h3 line. Sure enough, my opponent played it differently than I saw in round 1, finding a line with a much better chance to equalize, possibly inspired by the recent Harikrishna-Leko game. But I had anticipated this, and came up with the idea of playing g4 before castling long. I don't think it conclusively proves an advantage, but I had faith that it would work for one more game, and sure enough my opponent started thinking. Always nice when someone prepares something specific for you, but you still have them outgunned!
There are definitely risks involved in repeating lines constantly- nowadays anyone with a decent engine can come up with new ideas if they know what to prepare for. But, one should still have confidence and faith in the soundness of their lines, and remain undisturbed if an opponent plays something they don't normally play in order to try to target a specific line- it is still very possible that you will have them outprepared all the same.
Best of luck to all!
GM Sam Shankland