I think people are underestimating how difficult it is to consistently beat an efficient market. Doesn't matter how selective you are or how good your money management is. You can be on the same side as the book for 99% of those wagers and still won't come out ahead.
Better to press when winning then losingHere is the main reason
Most people want to make significant money
Most people do not have significant money to start with
And even people who do often fall into the same category
Lets say your bankroll is $1000 to start
In reality you probably shouldn't ever bet more than 2% on any play
But risk reward. So,people do
What fun is it to bet $10 a game? How much of a significant profit are you really gonna make? Not much. Not even over a year.
So, people will bet $50-100. Or even more
That is great if you start of on a good streak.
Lets say you do
How about $50 a game and you start out 20-10(66%).
Now your bankroll is at about $1450
Well, people will naturally increase their bets
What happens if you now go on a slight losing streak?
Lets say the next 57 games you go 27-30
You just lost 600
Now your record is 47-40 but you are down to $850 from $1000 when you should be up.
Thus the game continues
The further your bankroll goes down eventually at some point you may risk it all just to get back to $1000
And your odds of depleting said bankroll eventually increase
This is the main reaaon people lose
This goes against all sports betting conventional wisdom, but if you really don't have a lot of money and your name isn't Billy Walters, your best bet is to take some pocket change, really pick your spots and let it ride. Then cash out. Lather, rinse, repeat..
Forget a bankroll. Forget betting into very efficient markets trying to grind out a profit over a large volume of games. Forget looking for +EV bets. Forget money management betting 1-2% BR per play. Forget shopping for value. Discard all those betting cliches bookies love.
We've all had winning streaks. 5-0, 6-0, 8-0 doubling up each bet and pretty soon you're into real money.
Bettors win short term; bookies win long term.
You're not a bookie, so let it ride...