— Carrie Muskat (@CarrieMuskat) February 13, 2018
The Cubs have another possibility that cuts against the grain of baseball thinking today. The Cubs could employ a six man rotation, and it is clear that this isn’t an entirely hypothetical proposition. The Cubs personnel lends itself to considering this approach. The Cubs have used six man rotations in the past, and it could maximize the potential of the 2018 Cubs. Mike Montgomery has been clear about his desire to be a starting pitcher, and it is certainly a role that the front office thought about when they acquired him in 2016. Now Montgomery has said all the right things about being willing to do what is best for the team, and it is clear that he is the sixth best starter in the organization. Now Montgomery’s happiness isn’t the reason to make a drastic change, but perhaps the Cubs newest pitcher is.
Yu Darvish has pitched in the big leagues for six years. He has been used as a traditional MLB starter during that time frame, but he also has spoken in the past about how starters in Japan are traditionally used as being better suited for health. Darvish specifically mentioned it during the All-Star break the year before he went down with Tommy John surgery. Darvish started fewer than 30 games every year in NPB but went over 200 innings four times in his early 20s. Japanese starters on the whole have had far fewer Tommy John surgeries despite usage patterns like that. In NPB, starters typically receive five or six days of rest between starts. The health benefits could be huge for a team with Darvish and Tyler Chatwood’s injury history not to mention an aging Jon Lester. And the Cubs have already addressed the biggest problem with moving to a six man rotation in having six capable starters.
Now this plan is certainly cutting across the grain of current baseball thinking. The en vogue thinking is to limit the amount of pitches thrown by pitchers in every start. The initial reason is the health argument, but there is at least some anecdotal evidence from Japan that more rest in between starts might be a larger factor in health. The strategic reason for limiting pitches is harder to counter. The third time through the order penalty has been one of the arguments for shorter outings from starters, and bullpening has been successful in short bursts. The problem with this approach is that it burns out your bullpen quickly. The Cubs saw this in 2017 with an effective bullpen becoming almost wholly ineffective in October after a heavy workload in the first half of the season.
Another problem with a six man rotation is the fact that not all six starters are of the same quality. The top four starters are three former All Stars and an NL ERA champion. Tyler Chatwood is an intriguing upside play and has had some success as a big league starter. Mike Montgomery is completely unproven as a full time starter. So instead of a traditional rotation, the Cubs should consider a modified rotation. The Cubs should make sure that a starter never has to start on four days rest, but they should pitch their top five starters as frequently as possible within that constraint. How this would work would be that Mike Montgomery would get his first start April 3, but with off days he wouldn’t be needed again until April 16. Montgomery could pitch out of the bullpen some in between these extended breaks, but if things work out exactly as needed Montgomery would get 18 starts. Unfortunately things are unlikely to work out exactly as planned, but having a stretched out Montgomery to handle these situations isn’t a downside.
Mike Montgomery could be given a chance to earn a spot through this unique approach. This might help him as he struggled to adjust to the random usage. He was quoted as saying in a very interesting piece from Patrick Mooney:
“From a physical standpoint, it is hard. It took a toll on my body, my arm. Making starts and coming out of the bullpen three days later – and pitching multiple innings out of the bullpen – I don’t think it’s something that I want to do long-term.”
Going through the game logs and it isn’t hard to see what he is talking about. He threw more than 50 pitches on just 2 days rest 4 times. He threw over 40 pitches on just 1 days rest twice. From May 1 to May 7, he pitched in 3 games throwing a combined 133 pitches. The postseason woes suddenly make a lot more sense. Montgomery being given a regular role might allow for him to throw more innings and still be effective come October.
Getting buy in from the established starters may be tough. Jon Lester is used to working a certain way, and has always taken pride in reaching 200 innings. Last year marked the first time in five years that he didn’t reach that mark. You know that he has a strong desire to hit that mark again. It isn’t just a matter of pride though given that his vesting option on the seventh year is tied to innings pitched (400 in 2019-2020 or 200 in 2020). Kyle Hendricks also has a financial incentive to pitch as many innings as he can as he moves through arbitration.
Another issue with this plan is the strain that it would put on the bullpen. Mike Montgomery’s ability to soak up multiple innings was a major safety valve for Joe Maddon the past year and half. It would mean carrying 13 pitchers but only 7 relievers. The limits of the 25 man roster are fixed. However, the Cubs could make that play larger if they were willing to part with Justin Grimm. This isn’t something to be considered lightly given that we have seen just how good he can be. However, if inconsistent Grimm appears early on then the Cubs could rotate various relievers in that final spot like Dillon Maples, Rob Zastryzny, Dario Alvarez, Luke Farrell, and Cory Mazzoni who all have options this year. That can make that 7 men pen play a lot bigger and avoid some of the problems caused by that 25 man limit.
The Cubs are unlikely to try my plan from the start of the season. If I had to wager I think you will see that used during that the incredibly demanding stretch from late May to early July. It will probably be used late in the year if the Cubs have a comfortable lead. A more preemptive approach has the advantages that are laid out above. 2018 is an important year. The Cubs are playing with house money in the sense that they have a title in the bank, but it is going to be hard to not feel like a slight disappointment if that is the only title earned after this window fully closes.