You do everything you can. But sometimes, stuff happens. And as much as we’d like to have some sort of rational explanation for it, stuff still happens. If it seems random, there may be a perfectly good explanation – the world plays dice with us. And we are encouraged by Hashem to do the same!
Think of the famous Yom Kippur scapegoats. One is sacrificed on the altar. The other is thrown off the cliff. Which is which? The poor goats don’t get a vote. The Cohen lets the lots decide.
There are plenty of other examples. We cast lots to determine liability when a dead body is found midway between two cities. And there are examples of rabbis deciding ambiguous halachic decisions by flipping a coin. In Jewish law, we use such methods as a way of accepting that when we are faced with complete doubt, flipping a coin (or some other quasi-random way of making a decision) is the only way to decide which course of action is correct. Humans always make decisions based on insufficient data, but most of the time we lean one way or another sufficiently to avoid relying on a coin toss.
There is no principle in Jewish law that says that Hashem gets involved in matters of statistical luck. In one example, the Cohen had the job of assigning land to the tribes in Israel. He used both the urim v’tumim (which are a source of divine information) as well as drawing lots – since he uses lots as well as the urim v’tumim, it means that they are not divinely guided.
And so when Haman uses lots to decide on which day the Jews would be destroyed, he selected the date using a method that could not be influenced by Hashem. Lots are statistical creations. And while they cannot be purely random, they lead us nonetheless to a simple truth: Absent G-d (and humans in his image), the entire world can be described using statistics. The only anti-statistical forces we see in the world are people ourselves – it is people who challenge the odds, who achieve greatness despite the entirely dispassionate forces of the natural world.
But try as we might to improve the world (and we do!), on Purim and on Yom Kippur, we are forced to remember that, despite G-d and our unique role to improve the world, stuff still happens. Haman picks the data in Adar, and that is when all the action occurs. Purim is, after all, named after statistical chance! And on Yom Kippur, the poor unfortunate goat is selected to be thrown down a cliff.
None of this negates the reality that it is our job, as Jews, to improve the world, to triumph over evil. We are concerned mostly about other people, about elevating the world and reuniting the schisms in our souls and in our world. But even on Purim and Yom Kippur, two very holy days, we must not forget that the natural world is left to its own devices, that G-d created a universe that, to mangle Einstein, plays dice with us. Good luck with that.