I am taking the under of 8.5 runs here between these two teams. The Cardinals offense has gone ice cold of late, struggling to score runs as they have only been able to get 22 guys across the plate over their last 9 games. The Reds also are starting a good young pitcher in Ben Lively, who with an ERA of 3 and a WHIP of 1 on the year,

Lively had been pitching well as prior to his last start he hadn't allowed more than two runs in any of his previous three starts. He now sports a respectable 3.03 ERA and 1.01 WHIP on the year.
The Cardinals struggle to score in game 1's of a series for some reason and I think the UNDER is the right play here.