I've seen amazing simultaneous chess exhibitions,
Yes like Magnus Carlsen. He plays 10 blind games simultaneously and wins them all.
http://youtu.be/cTeDkyQUbyY
His brain must work differently than mine.
the most common cheat when blindfolds are involved is a tiny vision avenue.
That was my first suspicion. I guess this guy holds the world record for doing one RC blind in 21 sec. Looks more controlled in this video.
http://youtu.be/0RfJbcydNJ0
I guess that not every unbelievable thing that you might see is actually unbelievable.