WOW there is a lot of misinformation being put out... here are some FACTS:
1: I don't bet much, but the first bet was weighted and the second was basically with his money... and thats when I quit... original bet was 40:90 but he made it 100-100 for next, so he had many outs to get 10 of my dollars at the least, 40 at the most.... I understand the thinking behind it(if you keep more than doubleing the bet then you are practically assured of getting money at the end of a run of flips)
2: I am a proffesional magician and it was my own half dollar(from the bank) and it was completely legit as far as double headed and switches... believe me I am well versed and could have cheated if I had wanted to(I don't cheat though).
3: The probablility of a coin flipped is actually about 51% that it will land on the original side it was flipped from. please read this article:
http://news-service.stanford.edu/news/2004/june9/diaconis-69.html
And there are math/physics papers that have the actual proofs.... it would take thousands of tosses to detect this bias.
4: This is to many: OFFERING ANECDOTAL EVIDENCE THAT CONTRADICTS ALL LOGIC, PHYSICS, AND MATH IS JUST STUPID AND STOP IT!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
It doesnt matter if you "tested" it or "personally experianced" it. Unless you've conducted scienctific test or a proof in math to back it up, PLEASE stop spreading around nonsense in this forum and others.
The probability of a coin is for all intents and purposes 50/50, and even though you may have noticed a streak in one way(that is the thing about random, MANY streaks) there are just as many in the other direction so don't claim to know any "inside information" that goes against all science.
If out of 1,000,000 throws, you call head 0% of the time, 70% of the time or 100% of the time, you'll still win about 50% of the tosses.
5: Spinning coins is actually very different than flipping and not near 50%... coins actually ARE heavier on one side and when spun and then let come to rest, there is a large bias... but as previously mentioned this does not affect flipping.
6: There IS a method(that I know of) to toss a coin that you can control the outcome with a legit coin and even having someone else catch the coin(or table). It's 100% surefire with them catching and very very very close to that with a table or floor(obviously you can get a weird bounce every now and again but not often). I know this method, but as said I legit tossed it and I was tossing AND calling.(also I have double head/tails, weighted and magnetic(like dice) at my disposal and actually on my person, so I don't believe I would have been fooled if there was anything going on)
Anyway, I know he was doing an initial weight to get me playing and then more than doubling each bet so that he would always come out a winner, but I wasnt falling for that(I kept it either less than doubling or lower).
I guess he just bluffs when he loses 2-4 in a row, but damn the coin coming up 10 times heads threw me too and the only reason I gave it a second thought.
Hope this clarifies, and please don't listen to any stories about coins not being close to 50/50.... yes for weeks someone might notice a trend, but that is just how humans are, we try to find patterns in chaos.... but a coin flip IS near 50/50(actually 51% for starting side as published by Persi Diaconis).
Hope this clears some things up, if anything else let me know....
edit: I just wanted to say thanks to Tom and others than have provided good info and advice... Yes I'll be more careful and suspicious when gambling in the future...