Would you agree with someone who losses almost everytime they go into gambling to have an effective strategy?, of course we cannot say they have a good strategy even if they tried to make themselves believe that, an effective strategy is when you have a way that makes you to be wining and reduce your losses, so actually you might be thinking that you are making a different point by stating what an effective strategy means to people but to me is only effective when the person has 60 or 70 percent rate of wining.
If someone is losing every time then he should quit betting, because no active bettor with an effective strategy will say they dont win sometimes. They can be winning and they can be losing periodically. It can be also said that they may be taking higher risk when they bet.
I guess you have made your conclusion on what effective strategy means, well thats on you. Generally, effective strategy is a system that can improve your chances of winning by managing your risk based on analysis and experience.
On the last part you have defined what effective strategy is and I believe with this definition you should understand why I said not all the people had an effective strategy, although higher staking can be the reason why someone will be having strategy that's not working because if the gambler is the type that put together all the money they should have gamble separately by spreading out within the week to only stake it on one game and loss it becomes very severe, but if perhaps they had spread it possibly winning can take place but only one with a high staking has very low chance.