I went back to the start of the season and looked at every game where there were 70 or less points in 1H or 90 or more points. There were 39 of these games.
I then looked at the scoring in the second half. I didn’t have access to old second half lines but in 26 games it was a clear result and betting the opposite would have resulted in a 17-9 record. The other 13 were close but you would probably slightly over .500 betting the opposite in those games.
This analysis is obviously incomplete as it doesn’t take into the teams involved, injuries, etc. But it’s clear that betting the opposite total in 2H is a winner after a strange first half.
One other note - double digit dogs are 9-9 this year but if you take out the Aces at home the double digit dogs are 9-4.