One clunker against the San Diego Padres decimated his September ERA to this point, but Patrick Corbin has been lights out since August began.
In six August starts, Corbin went 4-2 with a 2.52 ERA and had 42 strikeouts against eight walks. In his last three August starts, Corbin went 8.0, 8.2 and 7.0 innings, a feat that Walker cannot boast.
Their numbers are similar but Corbin needs slightly fewer pitches per inning and has simply gone deeper into games more consistently. That matters more than anything right now.
Plus, it is always nice to have two lefties and two righties to fill out a postseason rotation.