These so called rules are for sports betting only.
1. Place a part a bankroll to play with.
2. Play 5% each bet of your bankroll.
3. Learn a lot 1-2 hour per day regarding the bet you are willing to place.
4. Play Asian Handicap in order to have better options and to start the game in win (usually when you play +1.5 or +2).
I think this one is a good strategy to try at least in the sports betting area.
but with managing your money and bankroll i guess it is the most effective strategy to prevent you in losing more than your winning , you will always can see the losing & winning amount as you manage it all and monitored. this is what always i do in sportsbetting, but not sure in another games.