It's true that it's all numbers, however you have to ensure you will be able to effectively execute your plan, sometimes when we are too weak it leads us to doing the opposite of our analyses, so still we need to be careful and to succeed requires all factors that are vital to be implemented well.
If it were so it would be possible to program a bot with a winning strategy and since bot can't be weak, it's a bot after all, it has no human weaknesses, the thing would be winning all the time. However, we all know that there's no such bot.
When we are losing, the problem is not that we are not following our strategies, but rather that no strategy is perfect enough to be a winning one all the time.