Investing seems to have a number or parallels to any mathematically-defined game, such as blackjack, cribbage or backgammon.  In blackjack, for instance, it is a mathematical fact that the house holds a certain edge by operation of the rules of the game itself.  That edge may be strategically reduced by the player to approximately 0.5% by employing certain methods of play, short of tracking or counting cards or various methods of ‘cheating’.  In a mathematical sense, the optimum long-term strategy is called ‘basic strategy’.  For those unfamiliar with the game, Basic Strategy is simply the mathematically preferable option in every given circumstance.  (If the dealer’s “up” card is x, and you hold y, the ‘percentage play’ is z.  Stand, hit, double-down, split pairs, etc.  Of course, ‘playing the percentages’ does not yield a winning result in any given hand, nor is it designed to.  It merely DECREASES the house edge over a large number of trials (hands).  The more trials (hands played), the closer the player’s result in employing basic strategy will approach the long term mean, i.e. the house edge of .5%.  Put another way, think back to college statistics, marbles and jars.  If you had a jar with 100 marbles, 70 of which were white, and 30 of which were black.  Reach in once…I won’t insult you by filling in the rest.