Bet Sizing

When it comes to betting on football games, there are many systems out there. The most popular systems seem to follow the same basic idea. It goes along with the idea of raising your bets when you’re winning and lowering them when you’re losing. That way you take full advantage of winning steaks and won’t get hurt on losing steaks. The reasoning behind this seems logical enough. That certainly sounds like good advice, but is it? As it turns out, that piece of advice has hurt far more gamblers than it’s helped. Raising and lowering your bet sizes actually makes it harder for you to win. Here’s a simple example: Take any series of 10 bets with 5 wins and 5 losses. If you bet the same amount on every game, you’re going to break even, no surprise there. Now let’s look at a sequence of bets, raising and lowering after a win or loss. It doesn’t matter what the order is for these 5 wins and 5 losses. I’ll do 2 sequences below. The one on the left is 5 wins followed by 5 losses. On the right, 5 losses followed by 5 winning bets. The bet size will be 10% of the total bankroll after the last bet. The bankroll starts out at $1000.

 

	Bet size	Bankroll			Bet size	Bankroll
		1000				1000
win	100	1100		loss	100	900
win	110	1210		loss	90	810
win	121	1331		loss	81	729
win	133	1464		loss	73	656
win	146	1611		loss	66	590
loss	161	1449		win	59	650
loss	145	1305		win	65	714
loss	130	1174		win	71	786
loss	117	1057		win	79	865
loss	106	951		win	86	951

 

The first thing we notice is both sequences end up losing money. Remember, when you bet the same amount on each game, you start with $1000 and after 5 wins and 5 losses you still have $1000. When you change bet sizes, you end up with $951. You’ve picked at the same win rate, 50%, and yet lost money. The order of the wins and losses can be in any order. As long as there are 5 wins and 5 losses, the results will always be the same… you’ll lose $49. The second thing to notice is when you juggle the bet sizes, you have to win at a higher percentage rate to make money. Where 50% was break even, now it’s a higher number.

There’s no doubt about it, raising and lowering your bet sizes makes it harder for you to win money.

This doesn’t mean to never raise your bet or lower it. If you use a bankroll, there will come a time when you should change bet sizes. As your bankroll grows, it only makes sense to raise your bets, and vice versa. However, you should change your bet size very rarely, as changing it does come with a hidden cost. If you don’t use a bankroll, you should never change your bet size during a season.

Most gamblers don’t understand this concept and consequently make it harder on themselves to win. Don’t fall into this trap!