The Chicago Cubs are having an incredible season, securing a comfortable lead in the National League Central Division thanks to one of baseball’s best offenses and a bullpen that has addressed early-season concerns. However, the key question for the Cubs’ potential as World Series contenders lies in the state of their starting pitching rotation.

The rotation has been significantly impacted by the loss of Justin Steele, who was diagnosed with a torn ulnar collateral ligament and requires Tommy John surgery. Additionally, co-ace Shota Imanaga has been placed on the injured list due to a hamstring injury. Despite these setbacks, rotation members Jameson Taillon and Matthew Boyd have performed admirably, helping to stabilize the team during the absences of their top starters. Offseason acquisition Colin Rea and rookie Cade Horton have exceeded expectations since joining the rotation, but the fifth starter, Ben Brown, has struggled.

Undoubtedly, Brown has the talent to compete at the major league level. According to Fangraphs, his Stuff+ rating, which evaluates pitching based on the physical characteristics of pitches independent of results, is at 98, just 2% below league average. This rating indicates that he has the potential to be a successful starter. Moreover, Brown’s average fastball velocity is among the highest of Cubs starters, and his devastating knuckle curveball has an impressive whiff rate of 43.6%. So why is Ben Brown having difficulties?

Brown’s performance has been inconsistent, resembling a Jekyll and Hyde situation. At his best, he demonstrates the potential to become one of the top starters in baseball. He has recorded three separate starts in which he pitched six or more innings without allowing a run, against high-caliber offenses like the Los Angeles Dodgers, the Detroit Tigers, and the Cincinnati Reds, who rank second, tenth, and eleventh in team offense, respectively. These performances prove that Brown’s best stuff can compete effectively.

However, when Brown struggles, it shows. He has allowed five or more earned runs in seven of his twelve starts this season and has failed to complete five innings in five of those outings. Teams expect their back-of-the-rotation starters to provide two essential things: first, a chance to win. The good version of Ben Brown does more than that—he can dominate opponents. However, his tendency to put the team in a disadvantageous position in more than half his starts creates challenges for the offense in securing victories. The second expectation for back-end starters is to log innings and keep the bullpen fresh. Brown’s inconsistency in going deep into games has strained the bullpen, limiting manager Craig Counsell’s options for subsequent games.

Many media members and fans have speculated about the reasons behind Brown’s inconsistency. A common theory is that using a two-pitch mix has significantly contributed to his struggles. Brown predominantly throws a four-seam fastball (58%) and a knuckle curveball (38%), which account for 96% of his pitches. The concern is that when one of these pitches isn’t working, opposing teams can focus on the other one, diminishing the effectiveness of his approach.

Pundits and fans have suggested that Brown needs to develop a third pitch to become a competitive starter. He is working on a newly developed changeup for left-handed hitters but still relies on a two-pitch mix against right-handed batters. While adding a third pitch could be beneficial, the more pressing issue is Brown’s need for consistent location with his two main pitches. He possesses the skill to succeed with these pitches, given proper command.

Traditionally, combining a fastball and curveball creates a north-and-south attack. High-velocity fastballs thrown up in the zone and curveballs that start at the same level but drop down create an effective tunneling technique. However, Brown has been more successful at inducing whiffs with his curveball when it’s located below the strike zone. Incorporating low fastballs into his repertoire may prove valuable. Targeting the bottom of the zone with fastballs could create a tunnel effect for his low curveball, increasing swing-and-miss opportunities later in the count. Conversely, low fastballs could induce looking strikes late in the count as hitters anticipate the curveball to drop.

Overall, Brown has struggled this season, sporting a 5.71 ERA. Nevertheless, there is still hope for his development. At just 25 years old, he showcases a high-velocity fastball and a highly effective secondary pitch. While developing a third pitch is helpful, consistently locating his primary two pitches is crucial for his success moving forward.