Links 8/2/11

Thanks for the links!

(Except the conservative-white-dude-denialists one; it's got a borked URL.)

The coin toss link reminded me of a man I knew at one time. In my younger days my friends and I hung out at a local pool hall quite often. We weren't hustlers or gamblers, just kids who liked to play pool and nothing else to do on a Friday night. There was always an unsavory element hanging around gambling and occasionally getting in fights, physical or otherwise. I noticed one guy that I had become mildly acquainted with won a lot more than his share of coin flips only when he tossed it (various rules and conditions of bets were often determined by a coin flip).

He was obviously manipulating it somehow, but his win rate and technique seemed subtle enough that I thought very few others picked up on it. One night when the hall was fairly empty and he was alone not getting any action I asked him how he did it. It probably wasn't the smartest idea but I was young and dumb enough to inquire. I assured him I wouldn't reveal his secret nor did I wish him to teach me the technique of how to do it. Having a casual relationship with him and never gambling myself probably tipped the scales in my favor from being beat up to him actually telling me.

Basically what he did was spin the coin. Instead of rotating on one of the axes through the thin side of the coin, he was able to toss it so the coin mainly rotated on the axis through the face of the coin. This would be very noticeable if it was spinning flatly through the air, but he was also able to impart just enough spin on the thin-side axis so that there was a significant amount of precession in its movement without it actually flipping over. If the called side was not originally up he could catch it and flip it over onto his other hand. He could by no means be perfect, one because it's physically impossible and two because too high of a win rate would make others suspicious, but the result was him winning much more than 50% of coin flip and probably a much higher rate on ones he felt were important.

It was quite impressive. Even after I knew what was happening I still couldn't distinguish his flips from others while the coin was in the air.

On coin tosses: When I was younger I could flip a coin, grab it out of the air, slam it on my wrist, and have it land on whatever side I pleased. (I perfected this over many bored hours working at a gas station.)

The trick is being able to quickly feel the difference between the smooth heads side and the rough tails side with your thumb as it's in your hand and moving toward your wrist. Then -- if needed -- just a quick rotation in the hand as you slap it to the wrist.