To bet or not to bet?

There is a saying in poker: know when to hold'em and when to fold'em.  This is just as true in betting on horses.  Know when to bet and when not to bet.  This rule of success is easy to say but hard to follow.

Always remember: your winning bets have to absorb your losing bets.  Losing bets put you in a hole.  If in doubt about a bet, don't bet.  A weakness in betting is betting too much and too frequently.  It's not easy to keep from betting especially if you are the type of person that enjoys the action.  This can be your downfall.  Establish a goal for yourself in betting.  One such goal might be "be a winner at the end of the day".  What does this mean?  It means that you have more money at the end of the day than when you started.

Okay but how do I do this?
First, you have to want to be a winner.
Second, only place bets that you have a high level of confidence in. If in doubt, don't bet.
Third, know when to not bet a race.  (Too many horses could win the race.)
Fourth, know when to stop and declare the "end of the day".  (If you're really ahead before the "end of the day" QUIT betting and keep your profits.)

If you think about it the only way to be a winner: "you must stop at some point when you are ahead".  There is no other way.