I would argue that "winning" here in general would be to play games where there is less randomness and more skill, where you will have a larger edge over someone who hasn't done their studying.
It doesn't make a lot of sense to apply yourself to areas where 90% of the result is determined by luck (unless you truly enjoy it).
I mentioned above that there are scenarios where failure is incredibly costly, but the opposite is sometimes also true. Job hunting comes to mind.
I use luck to describe anything with variance that I can't control. So by that measure, job hunting has a ton of luck involved. But I don't need to have a good win rate for job applications - I just need one job application to succeed.
That's something I can play the odds with - if I have a 10% chance of getting hired at any given company, I can send out 10 applications and have... what, a 60% chance of getting hired? I'm bad at math, but you get the point.
In Hearthstone terms, aggressive decks also used to use this strategy as well. I don't know if this still works, but at one point at least all a deck needed was a >50% win rate and enough games to hit legend because wins gave you more points than losses removed. Something like that, I forget the exact mechanic.
People would play decks that won or lost based on randomness very early - their overall percentage was pretty bad, but because they were just effective enough, and because their games were incredibly fast, players could take advantage of the fact that (at least at the time) wins were more valuable than losses.
Again, take that with a grain of salt. This wouldn't hold true for games where you get limited tries, or where losses matter a lot more than wins, etc. You have to figure out whether or not it makes sense for the specific 'game' you're playing.
> but at one point at least all a deck needed was a >50% win rate and enough games to hit legend because wins gave you more points than losses removed. Something like that, I forget the exact mechanic.
For anyone interested, it's that you gain/lose 1 "star" with each win/loss. And if you're on a "win streak", you gain extra stars, but never lose extra stars for being in a losing streak. So a win on average is slightly more than 1 star when you consider streak bonuses.
So you get a deck with roughly 50% winrate that can play matches as fast as possible. And then hope that in your 50/50 coin flip of a game, you end up getting "heads,heads,heads,tails,tails,tails" instead of "heads,tails,heads,tails,heads,tails". And it turns out doing this quickly can rank you up faster than slow games with a much higher winrate.
But also to your point, in Hearthstone terms reducing your randomness is also a significant part of strategy. For example a deck I run now has a card "Draw the lowest cost minion from your deck".
This card is valuable not just because it instantly puts a monster in my hand, but because it also gets it out of my deck. Reducing the chance that I will draw a low-cost minion in the late game, increasing my odds of drawing the high-cost cards I do want.
Like if you were playing Blackjack and had the option to "remove a 2 from the deck". Super useful when you want a face card. Not useful at all when you're holding a 17.
It doesn't make a lot of sense to apply yourself to areas where 90% of the result is determined by luck (unless you truly enjoy it).