Hall of Shame, Episode 2
In my defense, I was on a late-night blurry-visioned blitz binge when I missed this mate. Still, there is no reason for me to miss this as long as I still test positive for brain stem activity.
Make sure you're familiar with this mating mechanism...it pops up quite often, and you see it in a lot of tactics books.
1. Bxh7+ Kh8 2. Bg6+ Bh6 3. Qxh6+ Kg8 4. Qh7#
This was an example of chess blindness. During my few seconds of analysis I thought that the king would escape via f7, missing that my queen prevents that.

