If you pick Arizona and Pittsburgh vs the spread, it would be
Arizona +3.5 (OK)
Pittsburgh -6 (Pittsburgh has to win by more than 6 points, like your Pitt 23 - Balt 10 prediction) (So the minus means 'more than' right?)
Based on the outcomes you have stated, you think the Pitt/Balt game will produce only 33 total points, that would be under 34 total points
And the Phil/Ariz game has only 30 total points (like 17 to 13 final score), then that total is under 47 total points
Are you starting to understand? YES, I THINK