The inconsistency of one good start followed by one bad starts suggests an arm that lacks strength. So does a fastball that touched 90 mph only once against the Royals. He showed us what he's capable of doing the last two outings. He's had some good innings. The six-inning start is the cutoff line.
Good starters go six and more.
To be called a five-inning pitcher is an insult. Oliver has pitched less than six innings in 12 of his 18 starts. All have more starts overall than Oliver. I can go six, seven, eight innings. That's what I expect of myself.