Real Time Analytics

How To Judge The Angels Proposal For A Six-Man Rotation

Jae C. Hong- Associated Press

With the arrival of Japanese phenom Shohei Ohtani, the Angels are considering a six-man rotation. But is it a good idea?

When the Los Angeles Angels signed Japanese phenom Shohei Ohtani, they sent a message to the league that they were going to try and do something that has not been done in Major League Baseball for a while. Ohtani, who is not only a talented young pitcher but also a great hitter with power, is going to be a two-way player.

The idea is simple. When Ohtani is not scheduled to pitch, he would either play in the outfield or, most likely, be the designated hitter. Ohtani’s teammate Albert Pujols has been working out at first base with the hope that Ohtani would primarily be the designated hitter when he’s in the lineup. 

It is easy to see why Angels fans are particularly excited about Ohtani. He has shown in the Nippon Professional Baseball League that he has the potential to be both an above-average pitcher and hitter in the Major Leagues.

Take a look at his batting statistics in both 2016 and 2017:

Image title

Clearly, Ohtani has shown the ability to hit for power and average, while proving adept at getting on base. As a pitcher, he can strike out batters at a high rate while not allowing many walks: 

Image title

However, playing in Japan is different to playing in the Major Leagues. Starting pitchers pitch every seven days in Japan. In Major League Baseball, however, teams institute a five-man rotation, which gives a pitcher four to five days of rest on average

The Angels’ plan is to adopt a pitching rotation similar to what Ohtani was familiar with in Japan—to institute a six-man rotation. The idea behind it is that Ohtani, who has never pitched more than 160 ⅔ innings a year, will be able to adjust more smoothly into the major leagues if his pitching routine remains similar.

On paper, this proposal by the Angels would not only benefit Ohtani. With the eight starting pitchers manager Mike Scioscia currently has at his disposal, he only has one that has ever pitched more than 200 innings in a season.

Image title

The Angels have also struggled with injuries to their starting rotation over the past couple years. The hope is that a six-man rotation would be able to maximize the productivity and efficiency of their pitchers while keeping them fresh for the entire season and a potential postseason run.

That leaves one question for the Angels to answer: is a six-man rotation the best strategy to ensure success?

Some sabermetricians have dismissed the idea of a six-man rotation as being beneficial. Russell Carleton documented with a hypothesis how a six-man rotation does not yield more strikeouts and fewer walks with the extra day of rest. A six-man rotation would also result in ace pitchers pitching approximately 30-50 innings less per season, which could potentially diminish the impact they can have on the field. The estimation is that a number one starter pitcher would cost a team 1.6 wins under this reduced workload of a six-man rotation.

But for the Angels, they do not have a number one ace that is consistently dominant. Since Ohtani has not yet pitched in the Major Leagues, it would be presumptuous to assume he is a bona fide number one ace. Therefore, the Angels’ best proven pitcher is Garrett Richards, who has not pitched a full season since 2015 and who even then did not put up ace statistics. In 2015, he posted a 15-12 record with a 3.65 ERA, a 1.240 WHIP, and a 1.8 WAR. A 1.8 WAR is fine for an average, solid starter, but it is certainly low for an ace of any pitching staff.

So it is unlikely that, as Carleton states, an Angels pitcher not pitching enough would cost them wins. Instead, what this six-man rotation could potentially do is limit injuries. Take Tommy John Surgery for example:

Image title

Courtesy of Patrick Newman and Eno Sarris, they determined that although Japanese pitchers still are susceptible to major surgeries and injuries, it is at a far less rate than the pitchers in the Major Leagues. When it comes to the Angels, all of their pitchers over the past couple seasons have missed time, including some of them with season-ending surgeries.

Image title

As the chart shows, the Los Angeles Angels have been increasingly decimated over the past couple years with injuries. What should concern the Angels the most are the elbow injuries that five of their pitchers (Ohtani, Richards, Heaney, Tropeano, and Ramirez) have had. If the Angels have any hope of contending in 2018, their primary focus needs to be on the health of their starters. The best way to do that is to limit their workload and keep them well rested.

As others have noted, there has been an increase in elbow and arm injuries to pitchers over the past few years. However, elbow injuries to pitchers have been the most concerning especially since they have been significantly on the rise since 2002.

Image title

To back up this data, pitcher injuries were examined from 2006 to 2014 when no club instituted a six-man rotation. Using injury information from Baseball Prospectus, it was determined that an average starter during this period accrued about 4.2-4.5 days of rest between starts over the course of the season. To determine whether a six-man rotation would reduce injury risk, individual pitcher outings must be examined to see some evidence of an injury-prevention effect. 

The evidence revealed that there is a connection between rest periods and injury rates.

Image title

Although the numbers suggest a link, they do not tell the full story. There are still questions about causation. Furthermore, it remains to be seen whether a six-man rotation would be of benefit in the long-run. If pitcher injury results from the progressive buildup of damage in the arm or elbow, then a six-man rotation may only delay the inevitable.

However, the Angels plan to contend in 2018. Therefore, they have a short-term aim. Due to them not having an established bona fide ace but many solid pitchers (assuming they stay healthy), the Angels have the depth to make a six-man rotation work. By going to a six-man rotation, they can limit the stress on their pitchers’ elbows, which may lead to a better overall performance from their pitching staff.

If the Angels hope to contend, the health of their pitching staff is vital. As a result, a six-man rotation is not only a good idea for them to implement, but a necessary one.

(All of the statistics and information came from,, and, unless otherwise noted).

Edited by Brian Kang.

Who is the only other current two-way player in MLB?
Created 2/1/18
  1. Christian Bethancourt
  2. Jake Arrieta
  3. Billy Hamilton
  4. Daisuke Matsuzaka

Be the first to comment! 0 comments


What do you think?

Please log in or register to comment!