The Houston Astros starting four pitchers (Justin Verlander, Gerrit Cole, Dallas Keuchel, and Charlie Morton) over the season ranked first in the following categories.
Astros: 3.11 ERA, 3.2 FIP, 3.33 XFIP, 27.9 PITCHING WAR via Baseball-Reference.
The Astros also ranked first in run differential at years end. You can’t get there without a dominating starting four going deep into ballgames. That has been the key.
Looking at the top AL rotations.
All other staffs come in 2nd, the Indians currently sit at second behind the Astros, and they had their way with Corey Kluber in game one.