We sometimes don't know what will happen until it does. The best we can do is to make a guess. Sometimes this guess will be very often good, but it is still a guess and we need to be open to the idea that our guess was wrong in some aspects.
Suppose we could have a perfect guess though.
We can use the guess to figure out what would happen and it would always work. Okay, lets use it to determine what happens in the future in which we use it to determine what happens. Do you see the issue here? The guess references itself. So it can't predict the future in advance of it. There comes a point where it is looping and giving you the leading edge of what is knowable given the amount of time that has passed so far.
So we don't have the perfect guess, even when we have the perfect guess. We don't know what will happen before it happens, even if we know the rules that tell us what happens before they happen.
There are a bunch of wierd things that get implied by the math that is consequent to this, especially when you get into transpositional structures, but it isn't silly so much as it is non-sensory.
I mean, it does sound laughable. When Feynman said we guess when we do science and then validate the guesses with experiments people did laugh. Yet this is not because it is silly. It is because the non-sensory cases we can't differentiate from can only be differentiated from the sensory cases via the experiment.
What often happens though is that directly after the moment people pretend that it was all known before hand. It is a tricky moment, the present.
In order to think about this sensibly you have to think through the consequences of the infinite self-reference. Logic fails here. So does evidence. For example if you observe that your opponent is playing badly, modeling them as a bad player doesn't work, because if you choose to do this, they could exploit the bad model by playing better than that model would predict. So even though the evidence suggests that they are a bad player, the self-reference considerations forces you away from acting as if they actually are.
So lets say you play rock? They play paper. Lets say you play scissors? They play rock. Lets say you play paper. They play scissors.
Lets say you fully determine everything they are going to do using your complete knowledge of physics and you play rock because your model told you that they would play scissors... They will play paper; obviously.
Lets say you anticipate that and you play scissors. Then they play rock. As long as you claim that you can figure everything out, it means they could figure everything out. The harder you push against this, the harder it pushes back. You have to move with the force, diverting it, not fight against it. You've got to take advantage of the inevitability of being unable to overpower, not try to overpower. You have to act as if you can do everything at once, because the undecidability allows you to do so. Not try to determine everything, because if you try to, then you can't, because others try to do the same thing.
