I will write more later, but overall the simple approach did well…though not as well as expected. Current actual outcome: Senate 52D, House about
245 243R. The House discrepancy, about 1513 seats, is equivalent to about 1.6 1.4 percentage points of popular vote. Not ideal, but pretty good. If you’re dissatisfied, consider that this transparent, low-assumption calculation did as well as assumption-laden models such as Pollster and FiveThirtyEight. Furthermore, those models only put a House takeover at ~80% probability, which was obviously wrong.
This error is so statistically glaring. I am not sure what to think about it. More discussion of this, and the House result, later.