Explaining Ceddanne Rafaela’s Early August Slump

For nearly two months, Boston Red Sox outfielder Ceddanne Rafaela was one of the best players in baseball. Rafeala’s 171 wRC+ from the beginning of June to July 15 was the eighth best in baseball over that span.

Rafaela’s hot streak was in part due to how often he was pulling the ball in the air. In June and July, 30% of Rafaela’s fly balls were pulled. He had a 1.786 wOBA when he pulled the ball in the air, including nine home runs.

Through the first two months of the season, only about 12% of Rafaela’s fly balls were hit to the pull side. While Rafaela had success when he was able to pull it in the air, the lack of frequency limited him to a .647 OPS.

In August, Rafaela’s wRC+ is at 66 through 12 games. Rafaela’s slump coincides with Marcelo Mayer’s injury, causing the regular centerfielder to play more second base. While the position change could be partially to blame for the decline in offensive production, the numbers show there’s more to it than that.

Pitchers aren’t necessarily pitching around the Red Sox outfielder, but they are giving in less often. He’s seen a lower percentage of pitches in the “heart” zone, as defined by Baseball Savant, and has seen much fewer fastballs than he was earlier in the season.

Looking closer, it appears as if Rafaela is still hunting for fastballs, despite not getting as many of them. His average attack direction is seven degrees to the pull side in August. Out of context, that number can be confusing, but when we compare it to previous months, we begin to see the issue. In June, his average attack direction was one degree to the pull side. In July, it rose to four degrees.

Rafaela is catching the ball further in front of the plate than in any month this season, indicating an early swing. 10 of the 16 balls he’s pulled this month have been on the ground, most of which went for easy groundouts.

Nobody expects Rafaela to keep his offense pace from June and July, but if he wants to get back on track, readjusting his approach at the plate might be a solid first step.