Bello's 3.35 ERA looks strong on the surface, but underlying metrics suggest it should have been closer to a run higher. He benefited from an unusually low BABIP for a ground ball pitcher and a favorable left-on-base rate. Although he sharpened his control and did a better job limiting home runs, his strikeout rate dropped sharply to a modest 17.7 percent. A shift in pitch mix contributed to the decline: he threw more four-seamers and added a cutter while reducing his slider and changeup usage, even though those two pitches generate most of his whiffs. The Red Sox have a solid track record of helping pitchers adjust, so there's a pathway for Bello to regain some of his lost swing-and-miss ability. Still, if the strikeout rate remains low, his ERA is likely to fall in line with the estimators. Read Past Outlooks