In 2011, Ozzie Guillen implemented an unconventional six-man rotation, with Mark Buehrle, Gavin Floyd, John Danks, Edwin Jackson, Philip Humber and Jake Peavy. The rotation was a success, as all six pitchers ended the season with a FIP under four; however, the circumstances in favor of a six-man rotation in 2011 are much different than 2018.
The rotation changed from five to six in 2011 because all the pitchers were having productive seasons. The 2018 White Sox aren’t likely to be faced with that same problem, but with the organization still in a rebuild mindset it would be more productive to utilize a six-man rotation: Miguel Gonzalez, James Shields, Hector Santiago, Lucas Giolito, Reynaldo Lopez and Carson Fulmer.
Out of the group of Gonzalez, Shields and Santiago, Gonzalez is the best pitcher. He may seem like an outlier in this rotation, as his career first half vs. second half splits suggest he is a better second half pitcher. His career FIP in the second half is more than 40 points lower than the first, decreasing from 4.78 to 4.36.
However, Gonzalez has never been treated as a workhorse starter. The most innings he has pitched in the majors is 171.1, and he’s averaged just 153.2 innings since 2013. So, Gonzalez’s workload as a pitcher fits well into a six-man rotation. In fact, the lone season that his FIP increased from the first half to the second was in 2013, when he pitched his career-high 171.1 innings and his FIP rose from 4.41 to 4.50.
A six-man rotation is what Gonzalez is built for, and the Sox should look to take advantage of that.
Ol’ Big Game is a shell of himself compared to his Tampa Bay Rays and Kansas City Royals days. His career FIP from the first half to the second increases from 3.94 to 4.28, and the difference has been more drastic in recent years.
In 2016, the last full season he pitched, Shields’s FIP rose from 5.34 to 6.86 from the first half to the second. In 2015, his last full season as a San Diego Padres pitcher, his FIP rose from 4.21 to 4.78.
White Sox fans know that Shields is not what he used to be, but if his innings are cut down like last season, he should provide more value down the stretch. Injuries forced Shields to miss starts in the first half of the season last year, and in those 36.1 first-half innings, his FIP was 6.90. In the 80.2 innings he pitched in the second half, his FIP dropped down to 5.35.
That’s still abysmal, but it proves that with a lesser workload, Shields can be more productive—albeit still hard to watch.
Like Shields, Santiago also has shown that he falters down the stretch. However, his addition this offseason could be the final piece to the puzzle of a six-man rotation.
Santiago’s best seasons, in terms of FIP, were in 2013 and 2014, when he posted 4.44 and 4.29 FIPs. In those seasons, he had a Mike Montgomery-esque role, pitching in 64 games and starting 47 of them.
Santiago should take on a similar role in 2018 if he makes the 25-man roster, because he clearly could not handle a pure starting role. In 2015, Santiago’s FIP jumped to 4.70, and then took off in 2016, when his FIP was 5.31; he pitched more than 180 innings in both seasons. Coming off a year in which he was sidelined with shoulder and back injuries, Santiago is best fitted for an innings limit under a six-man rotation.
Lucas Giolito and Reynaldo Lopez
The first pair of heralded White Sox pitching prospects came up in 2017, and they showed promise, both are coming off seasons with a career high in innings.
Lopez pitched in 168.2 innings, and Giolito pitched in 174. Normally, both pitchers should prepare to increase their workload to 200 innings, but with the Sox in the midst of a rebuild, there is no reason to risk their future.
In their small sample sizes in the majors in 2016 and 2017, both pitchers saw significant drops in their velocity due to an increase in innings pitched. In 2016, Lopez’s fastball averaged 96.7 mph compared to 94.8 in 2017. For Giolito, in 2016 his fastball averaged 94.1 mph and dropped to 92.7 the next year.
A six-man rotation can provide these young starters a season in which working on velocity and “stuff” is more pertinent to their development than an increase in workload. If 2019 is the beginning of the end of the rebuild, there is no need to risk a major innings increase in 2018.
Along the same lines as Lopez and Giolito, Fulmer will also look to have an innings increase in the 2018 season. Even under the typical workload of a six-man rotation, Fulmer would find himself with a new career high in innings pitched, beyond his 2016 mark of 149.1 in the minors and Chicago.
When a young pitcher approaches a career-high innings mark, like Giolito and Lopez, they lose velocity and over-pitch. Fulmer will find himself in that position in 2018, much like Dylan Bundy of the Baltimore Orioles did in 2017.
Bundy’s innings workload went from 109.2 to 169.2 from 2016 to 2017. In his first 13 starts of the 2017 season, Bundy averaged a 57 game score, with 82.2 innings pitched. In his next seven starts, during which he set a new career high in innings, Bundy’s average game score fell to 40. At that point, the Orioles made the conscious decision to stop starting Bundy on the regular four days rest. In his last eight starts, during which he started on four days rest only once, his average game score climbed back up to 59.
If the Sox started Fulmer every sixth day, like Bundy in his last eight starts of 2017, Fulmer would be more productive as he nears his career high in innings.