Let’s briefly look at the last five seasons. From 2015-2018, the Diamondbacks win-loss record was 34-23 (plus the wild card win) against the Rockies. Then it shifted. From 2018-2019, the Diamondbacks were 17-21 against the Rockies. Likely this season shifts back in the Diamondbacks favor.
With records above 500, the Rockies and the Diamondbacks dream of the playoffs. These teams are strongly motivated to win. The series will be hard fought.
I predict the Diamondbacks will win the series. Let’s look at two reasons (temperatures and rotation collapse).