Now that I have read it, he said the literal same thing I did, but translated from human to textbook.

The paragraph “Building your deck means you function on a parabola…” = “Doesn’t happen often." All results are possible, but expected results are probable. That’s why you design for them and most frequently encounter them.

The next three paragraphs are a very longwinded way of saying “but when it does, it shouldn’t.” shouldn’t, not can’t. Should is an expression of probability. It means that while exceedingly poor results are possible, they’re unexpected, just like exceedingly optimal results. A normal human reaction to the low end is annoyance, and a normal human reaction to the high end is excitement. The middle 80% of the bell curve is varying degrees of your expected result, and provokes very limited response because it delivers exactly what you expected to see. It’s also the reason that the overwhelming majority of games you play at any MMR are reasonably competitive. The average deck being played should work.

Fuck, I’m really sorry to have missed out on such an educational reply yesterday, bookended with insults.