In 2016, there was a pitcher who had a 2.47 ERA in the National League before he was acquired by the Boston Red Sox and got rocked by the American League, posting a 4.59 ERA while barely making it through six innings pitched without implosion. Many wondered if this trade was a horrible mistake by the Red Sox, as this pitcher simply couldn’t hang in the AL East gauntlet after a smooth ride for the San Diego Padres.
However, that same pitcher had a bounce-back season in 2017, posting a respectable 3.32 ERA while qualifying as a Cy Young candidate.