Not sure I understand the question. My point was over his first 2-2 1/2 years, there were many times when Bello melted down after an error or a missed call by an ump and allowed big innings. That inning was the type that often resulted in a 4 or 5 run inning earlier in his career. It hasn’t happened much in the last month or so. He’s buckled down and made pitches to get out of jams, a sign of a maturing pitcher.
The next step for Bello would be to become efficient enough to regularly go 7 innings. 5 leaves too much up to the pen.
As for Cole, every pitcher has a team he can beat by just throwing his glove out there. Each pitcher has a “who’s your Daddy” team. The Red Sox have been the latter for Cole, going back to his Houston days but especially since he’s come to NY.
The A’s have been that team for Bello so far in his career.