The optimum wager approach to capital growth in any risky venture is calculated using the Kelly criterion. Basically it says you divide the risk by the reward and get a percentage of your bankroll to wager on any particular bet. It's very aggressive, and there are several good reasons to bet less than optimum, so I'll save you the math and heartache and just tell you you should simply bet 2% to 4% of your current bankroll on every bet. The more conservative, more plays you have, or less accurate your handicapping the more you should lean toward 2%. The less conservative, less plays you have, or more accurate your handicapping the more you should lean toward 4%. In any case you should practice "Unit Equalization" with this strategy to make sure your true bet size is the always close to your unit percentage.

Also, I like to be slightly more aggressive when I am winning. So I use a small sliding scale on top of by base unit percentage. It's only about +/-0.25% on the extremes (the cutoffs of which are your decision), and it should never jump too quickly over a small bankroll move. For example if my base unit is 2% and I am down 20%, I adjust my base percentage down by -0.15%, and conversely, if I am up 50% I increase by base percentage approximately +0.25% to 2.25%. So in effect my base unit percentage will move between 1.75% to 2.25% based on how the overall season is going. I find this little wrinkle quite effective. It slows the betting when you are down, and boosts your bets when you are up, yet it never varies too much from optimum strategy. It's more of a psychological crutch than anything. It helps us feel better on both extremes, which helps us continue proper betting habits, which most importantly keeps us long term winners.

(c) Parrish Heppenstall