Think of Tic-Tac-Toe's game-tree; that's a set of all possible choices that can be made in different branches of the game. Once you have an idea of the shape of the results those choices, such as "putting an X here causes me to lose more often than I win", you can make your choice based on that information so that you /don't/ choose the portions of the tree with the worst outcomes, thus narrowing the range of potential futures to ones which are better. Instead of spreading your future probability across 26,830 distinct timelines, in which you win less than half, you could spread your future across, say, 10,000 distinct timelines, in which you win 3/4s of them. (Numbers are just illustrative, not actually the real odds involved.)
Chess has a much more complicated game-tree; real life has an even more complicated game-tree; but the same principles should apply.
you can make your choice based on that information so that you /don't/ choose the portions of the tree with the worst outcomes
Nope. Every time this-you chooses a particular portion of the tree, other-yous choose all the other portions of the tree. You narrow "the range of potential futures" in one specific timeline, you cannot narrow the range of possible futures in all timelines.
I haven't been able to find the source of the idea, but I've recently been reminded of:
This is, of course, based on the Multiple Worlds Interpretation: if the lottery has one-in-a-million odds, then for every million timelines in which you buy a lottery ticket, in one timeline you'll win it. There's a certain amount of friction - it's not a perfect wealth transfer - based on the lottery's odds. But, looked at from this perspective, the question of "should I buy a lottery ticket?" seems like it might be slightly more complicated than "it's a tax on idiots".
But I'm reminded of my current .sig: "Then again, I could be wrong." And even if this is, in fact, a valid viewpoint, it brings up further questions, such as: how can the friction be minimized, and the efficiency of the transfer be maximized? Does deliberately introducing randomness at any point in the process ensure that at least some of your MWI-selves gain a benefit, as opposed to buying a ticket after the numbers have been chosen but before they've been revealed?
How interesting can this idea be made to be?