Before placing bet, almost every bettor analyzes the sporting events of bookmaker's line and bet money for those what in his opinion may be correct, that is, assumption coincide with actual result. If forecast correct - bet wins, if predicted incorrectly - bet lose.
Most bettors choose match for betting when don't sure in result and as a result lose money.
According to my calculations, over 80% of bets bettors make random and more than 70% of bets lose. For such wagers can be attributed bet on your favorite team, bet parlay or bet on sports matches, which is broadcast on TV.
Typically, similar stakes don't exceed $20 and losses from loss doesn't cause significant financial damage to bettor. But if we sum amount of wins and losses for several years, total loss could amount to several thousand dollars.
Thus, the eleventh bettor's mistake: place bet when don't sure.