Not sure if it can be outlandish enough to be considered unorthodox, but my favorite nonmainstream opening is sort of a modified Nimzo Larsen Attack/Reverse Queen's Indian. I haven't really seen the way I play it in any book or many moves deep at all into the database. I tried to find books on it, but the actual Nimzo Larsen is played differently, a lot of the times with f4, which I never do. The reason for this is probably because the way I do it is not good and no master would play it. But, I (almost) always get a good position, it's fun, and it's usually very safe. I've used it in serious tournament games and performed no worse than mainstream openings. Notice that I hedge all of my claims because if anyone with a high rating thought it sucked and wanted to play against me to bust it, it would probably fall apart into dust. But it's fun as shit.
Favorite unorthodox opening
Sort:
.