There is a much simpler way of winning than carefully building up your abstract-reasoning ability to the point where it produces usefully accurate, unbiased, well-calibrated probability distributions over relevant outcome spaces.

The simpler way is just to recognize that, as a human in a western society, you won't lose much more or win much more than the other humans around you. So you may as well dump the abstract reasoning and rationality, and pick some humans who seem to live relatively non-awful lives (e.g. your colleagues/classmates) and take whatever actions they take. Believe what they believe, even if it seems irrational. Do what they do.

Careful probability estimation and actions taken based upon anticipations of consequences is the kind of cognitive algorithm befitting a lone agent who actually reaps what (s)he sows. For a human, herd-mentality seems to be the more elegant solution: elegant in the sense that the epistemology is hard to get right, but there is a robust argument about consequences and utilities: almost all of the relatively-average-strategy humans in the herd will get roughly the same deal out of life.

Research from hedonic psychology on the "Hedonic Treadmill" effect backs this up further: even if you make more (or less) money than average, you probably won't actually be happier or better (worse) off.

Of course there are details and complications: which subgroup of humans do you join? How do you make the tradeoff between different subcultures etc. But still, you don't even need a general solution to that problem, you only need to decide which of the handful of specific subcultures available to you seems best for you.

And, of course, it goes without saying that this strategy is useless for someone who is determined to invest emotionally in a nonstandard life-narrative, like utilitarian charity or life-extension. From this point of view, one might object that joining the herd is selfish in the sense that it isn't the action which maximizes utility across the herd; but then again most people don't have a utilitarian concept of selfishness and don't count benefit to random strangers as part of their actual near-mode, actionable goal set, so from their axiological point of view, herding is an acceptable solution.