Six-Man Rotations and the Chicago Cubs

In response to all the recent issues, would using a six-man rotation provide relief for the Cubs reeling starters?

We’re fifty two games into the 2017 regular season and the Chicago Cubs starting pitchers still haven’t recovered from the lingering effects of their World Series hangovers.

In a shocking contrast compared to the 2016 regular season, the Cubs starting rotation has been in or near the bottom third of MLB in many major statistical categories. They rank 22nd in ERA (4.64), 2oth in batting average against (.263), 22nd in WHIP (1.40), 22nd in weighted on-base average against(wOBA; .334), and 13th in fielding independent pitching (FIP; 4.19; proving that it isn’t all the defense’s fault either).

Would a six-man rotation create the necessary shake-up to nudge some of the Cubs starters back on the right track? Prior to the season, reports indicated that the Cubs were likely to utilize a six-man rotation at some point in 2017. Per New York Post writer Joel Sherman.

Last September, with the division in hand and their starters already building significant innings, the Cubs went to a sixth starter, mainly Mike Montgomery. Having not picked up the option on Jason Hammel, the Cubs intend to look at Montgomery as one of the main starters. They also plan to utilize a sixth starter, perhaps as early as April, though the Cubs have five off-days in the first month of the season.

Maddon also weighed the possibility of using a “hybrid setup,” where two pitchers would alternate between pitching in the fifth spot in the rotation. When either of the two pitchers wasn’t starting, they would pitch out of the bullpen.

So far, none of these rotational plans have materialized. The Cubs employed a starting rotation of Jon Lester, Jake Arrieta, Kyle Hendricks, John Lackey, and Brett Anderson for the first month of the season until they had to make a quick audible when Anderson strained his lower back in early May and had to go to the disabled list. Since then, Eddie Butler has joined the other four starters to round out the rotation. His erratic pitching has done little to shore up the back end of a rotation that had previously suffered through Anderson’s ugly 8.18 ERA through six starts.

With Anderson healthy again, the Cubs could choose to abandon the Eddie Butler-experiment and revert back to the veteran Anderson. Or they could give up on both pitchers, and move reliever Mike Montgomery from the bullpen to the starting rotation. His extensive arsenal of pitches coupled with his ability to thrive in multiple-inning relief appearances make him well suited to acclimate quickly to a starting role. Additionally, he has started in 23 games in his career so he has some experience in this role.

Outside of using one of these three players in a traditional five-man rotation, there is another option. Would the Cubs consider squeezing two of the above pitchers into starting rotation roles, thus creating a six-man starting rotation?

Last season when the Cubs were comfortably in first place in September, Maddon employed a six-man rotation to rest his starters for the postseason. Presumably, if circumstance allows, this strategy would be on the table this season as well. They could also go with the “hybrid” strategy discussed above that Maddon was so keen about before the beginning of the season.

Depending on how the Cubs approach the trade deadline, another pitcher could enter this conversation. Perhaps, the Cubs land a starting pitcher who is significantly better than Butler, Anderson, and Montgomery. In this scenario, the Cubs could just insert him in the fifth spot and abandon the six-man rotation idea.

The look of the Chicago Cubs starting rotation could diverge in several different directions depending on how the remainder of the season unfolds. Would the Cubs benefit from using a six-man rotation, or should they keep the status quo and ride the season out with the traditional five-man setup?

Argument Against A Six-Man Rotation

Obvious drawbacks make the six-man rotation model far less popular than the more traditional five-man rotation that most modern MLB teams utilize.

Teams employing the six-man rotation would get less starts per season from their best pitchers, which would theoretically hurt their chances of winning.

In a 162-game season, each starter in a five-man rotation would pitch 32 times. If a team extends their rotation to six starters, then each pitcher only pitches 27 times. Of course, this assumes no injuries or other extenuating circumstances that would cause a pitcher to miss a start. However, the point still remains, the more pitchers a team has in the rotation, the less times the aces get to pitch.

Applied to the Cubs, this would be like adding Montgomery as the sixth starter and having him take five starts away from Lester. Not ideal, especially for a team in the thick of a very close postseason race. Every win is important if making the postseason for the third-consecutive season remains the ultimate goal, and the Cubs can’t afford to throw away games at this point.

The most recycled justification for six-man rotations is that they provide a much-needed reprieve for the starters. Onlookers tend to associate rest with better performances, therefore manufacturing a six-man rotation would seem beneficial, especially for this current Cubs team.

Combining the postseason and the regular season, the Cubs have four starters on their current roster (Lester, Hendricks, Arrieta, and Lackey) who pitched more than 200 innings last season. Three of these players are over 30 years old. In addition, Arrieta and Hendricks have endured well-documented velocity issues at times this season.

If there ever was a rotation in need of some rest and recovery, it’d be the Cubs 2017 starting staff. However, contrary to popular belief, there isn’t a strong correlation between extra rest for a starting pitcher and better performance. Per Fox Sports Sabermetric expert Russell Carleton.

These findings eliminate much of the incentive to experiment with a six-man rotation.

Finally, having a six-man rotation is worthless if a team doesn’t have six reliable starters. Throwing a starter out there for the sake of creating a six-man rotation is counterintuitive. Why throw away wins by having a pitcher start who is no good just to rest everybody else? Maybe this strategy makes sense for a team that is a shoo in to make the postseason. However, the Cubs don’t have that luxury this season. The team is below .500 and 2.5 games out of first place in the National League Central division.

The Cubs simply can’t afford to do something that doesn’t maximize their chances of winning every game.

Argument For A Six-Man Rotation

Although a six-man rotation doesn’t correlate cleanly with more quality performances, FiveThirtyEight writer Rob Arthur found that there is a correlation between length of rest and injury rate.

I found that there is a strong link between rest and injury rates. Looking at starts on three days of rest, 1.7 percent of pitchers suffered a reported injury within the next two weeks. These results hold for time windows going out to about 60 days, after which the correlation between rest and injury rates trails off. At four days of rest, the typical amount in the modern age, that number drops precipitously to 1.0 percent. (Maybe that helps explain why the five-man rotation came to be.) Then the injury risk falls even further: at five days of rest — which would be standard for a six-man rotation — just 0.8 percent of pitchers are injured in the next 14 days, for a 20 percent decrease compared with four days of rest. That is a potentially meaningful drop in injury risk. The difference in injury probability over two weeks hovers right at the edge of statistical significance (p=.06, using a two-tailed Fisher’s exact test), partially because the probability of an injury occurring over any two-week span is quite low. If you extend the test to consider longer time windows (such as 21 days), the p-value drops below .05.

In May 2014, FanGraphs.com writer Eno Sarris found that Japanese professional baseball players average less Tommy John surgeries per year than MLB players. He cited a country-wide standard where Japanese professional baseball teams generally employ a six-man rotation as a plausible explanation for this trend.

The statistics are a few years outdated, but nonetheless important as Arthur used this data as a baseline for his more recent study.

Injury prevention will always be a big part of baseball. Anything that can be done to protect a pitcher’s arm should be considered at length. Starting pitchers are among a team’s most valuable financial assets, and protecting these assets will always be very important.

What Is Best For the Cubs?

Last season, Maddon utilized a six-man rotation at the end of the regular season to rest his starters for the postseason. We know how that decision panned out in October and November.

However, Maddon used that six-man rotation under a completely different set of circumstances. Last season, the Cubs had a comfy lead in the NL Central and clinched the postseason early, therefore resting the starters at the end of the season made perfect sense.

However, right now it appears that the Cubs path to the postseason this year will be far from a cakewalk. Things could change by the time September rolls around, but the race for the NL Central crown is currently tighter than anybody anticipated. Therefore, the Cubs need their best starters to pitch as frequently as possible. Proactive rest and injury prevention means nothing if the team doesn’t even make the postseason.

Sometimes desperate times like the present call for desperate measures like a six-man rotation. However, in the Cub’s case, the cons of this strategy far outweigh the pros and if the club is serious about repeating as World Series champions, they need to maximize their chance of winning every game by deploying a five-man rotation.

Paul Steeno spent 11 years pretending he was good at running. After hanging up the track spikes and officially becoming an elite hobby jogger, he decided to do something that he was actually good at: like writing about the Cubs. He is also a perpetually frustrated Chicago Bulls fan. This one time he got super lucky and ran 3:52 in the 1500-meter run.