1-2g2c1 Testability matters only when you have a good explanation (hard-to-vary explanation)

1-2g2s7b You can’t justify the predicted value of the probability inductively, because theory (i.e., the laws of physics) provides the probability, not the experiment

Every formula purporting to predict the sequence of outcomes will eventually fail: that tests the unpredictability. And in the overwhelming majority of universes (and histories) the surge will happen approximately half the time: that tests the predicted value of the probability. Only a tiny proportion of the instances of the observers will see anything different