The Fatal Blunder
I'm pretty sure this has already been blogged about, but here are some examples where a much lower ranked player (me) has beaten a much higher ranked player because of one blunder. Don't fall to one of the traps:
Attacks f2 square:
As you can see, we were about 300 apart.
Here's another one where black had an advantage but lost due to a FATAL blunder:
As you can see, we were about 500 apart. The funny thing is, I offered him a draw. So never underestimate your opponent and don't always decline the draw. Thanks to nagiciec and upupae for these games.