HEADS OR TAILS. A Scientific Attempt to Explain the Fall of a Coin.

Te Aroha News, Volume V, Issue 215, 13 August 1887, Page 7

HEADS OR TAILS. A Scientific Attempt to Explain the Fall of a Coin.

Mr Richard A. Pkoctor, in his new book on "Chance and Luck," touches upon one point which must at one time have interested almost everybody. It is the notion that it you to.ss a coin, .say ten times, in succession, and it comes down "tails'' it is more likely on the eleventh throw* to come down "heads" than "tails." The truth appears to be this, that if you tos& for an hour "heads" will not exceed "tails" or " tails "' " heads " in a greater ratio than twenty-one to twenty. If you toss for a day the inequality will not be greater than 11 to 100. And yet, if during that time you toss "tails' ten times in succession (as yon may often do), the.c will be no more likelihood of " heads "than of " tails " on the ele\enth throw. It is, indeed, obviously out of the question that anything that" has previously taken place can ha\e given the coin a tendency to come dou n in one way rather than in another. The notion is perhaps capable of a reduction to absurdity in tins way : Suppote it to be true that a coin which has come town "tails" ten times in succession is moie likely at the eleventh throw to come down " heads " than " taiK" Now let the tosser who has thiown "tails ' ten times retrain fiom making the eleventh throw. Let him put the coin in his pocket and toss it a year hence ; it is still irr re likely to come down " heads " than " tails." Oc let him not toss at all, but pass it to another, who will toss it five yeai 8 after. As the probability inheies in the coin, it is still more likely to come down "heads ' than "tails." Supposing all this be true, it would appear that you might take up an old Roman coin and toss it thinking the chances to be even, whereas the piobabilitics had really been decided by the lasb pitcher who tossed it 2,000 years ago. One can .suppose this idea to a proper subject for the reverie of a schoolboy's half holiday. But Mr Proctor mentions the ca.se of an Englishman, an accomplished gambler, who made it the basis of a " system "at roulette. He watched the table for two hours, noting carefully the number* which came up during that time. Then he staked his money upon the numbers which had come up very seldom «r not at all. The first day the Englishman won L7OO in a single hour. His exultation Avas great. He had discovered the philosopher's stone. Within a week, however, he had lost it all.