A scientist makes a prediction based on a theory. He then tests the prediction in the lab. The test works as predicted (within a margin of error). Therefore, the theory has some validity. A GM makes a decision based on a theory and some facts. He then tests the decision on the field in the form of giving the player an opportunity. The prediction holds, as the player was successful. Therefore, the decision was right. A scientist makes a prediction based on a theory. He then tests the prediction in the lab. Unfortunately, the test fails to show what he expects. This invalidates the theory. A GM signs a player based on a theory and some facts. He then tests the theory on the field in the form of giving the player an opportunity. Unfortunately, the test fails as the player fails to perform as well as the GM's theory predicted. Therefore, the decision was wrong. This is the kind of reasoning we use in everyday life. I fail to see that it is invalid or it's "just not how the world works." I do web marketing. We build experiences and test them in multivariate settings. The one that works the best gets adopted. We then continue to test that experience and iteratively improve it. The whole premise is that you can't really know all that much about how an experience will work in advance until you test it. When you test it, you can say, "I guess option B was best." This is a lot like what GMs do. They have limited data. Humans are not robots. So they take their best shot. If it doesn't work out, they say, "Well, I guess I was wrong." If everybody knew the right answer before trying it, it wouldn't be a game. The guys who play the game the best win. But even the best GMs are right a little better than half the time, which is why they hedge their bets by getting depth. Oh, and the stats guy never said it was Correia. He said it was a player they were considering acquiring. It seems likely that if he did it for one player, he did it for every player they acquired.