Edinson Volquez is the latest "bounce-back" candidate brought into the organization.

What Should You Expect From Each Rotation Spot?

Back in 2006, Jeff Sackmann wrote an article in the Hardball Times taking a look at what should be expected from each rotation spot. His research was done because people tend to overestimate how good a pitcher should be. Sackmann studied the 2006 season to find the results for each spot in the rotation, using the following method:

For the purposes of this article, it’s necessary to define exactly what a #1 starter (or #2, or #3) is. To keep things as simple as possible, I used ERA as a measure of pitching ability. I also figured that each rotation spot accounts for 32 starts. On many teams, the #1 guy isn’t the same for the whole season. For example, let’s look at the 2006 Twins. Here are all of the pitchers who made more than one start for Minnesota last year:

Starter GS      ERA
Liriano 16      2.16
Santana 34      2.77
Bonser  18      4.22
Radke   28      4.32
Garza   9       5.76
Silva   31      5.94
Baker   16      6.37
Lohse   8       7.07

By ERA, Francisco Liriano was the best of these guys, but he only made 16 starts. So, he made half of the “#1 starter” starts. Since Johan Santana is next in line, I assigned 16 of his starts to round out a composite #1 starter. Thus, the Twins #1 starter was half Santana, half Liriano. Santana’s remaining 18 starts were assigned to the composite #2 starter.

Intuitively speaking, that distribution is a reflection of the fact that, while Liriano was in the rotation, Santana was #2. When Liriano was in the bullpen or on the disabled list, Santana was #1.

Sackmann discovered that the rotation spots broke down as follows:

Lg      #1      #2      #3      #4      #5
MLB     3.60    4.14    4.58    5.10    6.24
AL      3.70    4.24    4.58    5.09    6.22
NL      3.51    4.04    4.57    5.11    6.26

Prior to the 2011 season I updated Sackmann’s research, using the exact same method he used, and looking at the 2010 results. Here were the results four years after Sackmann’s first update.

2010 update:

Lg      #1      #2      #3      #4      #5
MLB     3.10    3.61    4.15    4.62    5.69
AL      3.24    3.71    4.28    4.76    5.68
NL      2.99    3.53    4.03    4.49    5.70

As you can see, the league saw drastic improvements across the board. There was almost a half run improvement at each starting spot from 2006 to 2010. That said, there was still some disconnect between an actual number four and number five starter, and what people think of as a number four and a number five starter. The opinions that people have of a back of the rotation starter are much more optimistic than the reality of what the average back of the rotation starter produces.

I have been wanting to update these numbers this year, since it has been three years since the last research. In that time, the pitching numbers have gone down once again, and I don’t need a big study to show that. Last year the average ERA in baseball was 3.87. The year before it was 4.01. The 2013 average is the lowest in baseball since the 1992 season.

I don’t know if the 2013 numbers represent a new trend, of if they represent an outlier. It might not be a good idea to base this research entirely on the 2013 season. But that’s what I’m going with for this update, to show how the numbers compare to the 2010 results, and to give an updated look at what should be expected from each rotation spot. Here are the results, by rotation spot. The 2010 results are in parenthesis.

#1 Starter

MLB Average: 2.82 (3.10)

MLB Median: 3.07 (3.09)

AL Average: 3.07 (3.24)

NL Average: 2.80 (2.99)

MLB Best/Worst: 1.83 / 4.11 (2.08 / 4.17)

Average of the Top 15 Rotations: 2.70 (2.84)

Average of the Bottom 15 Rotations: 3.17 (3.37)

MLB Range of the 11-20 Ranked Rotations: 2.55 – 2.91 (2.88 – 3.35)

The median didn’t change here, although the average dropped about 30 points. The average of the top rotations improved by 14 points, while the average of the bottom rotations improved by 20 points. The mid-range rankings went from 2.88-3.35 in 2010, to 2.55-2.91 this year. That means the top 20 teams all had a 2.91 ERA or better in their best 33 starts of the season.

#2 Starter

MLB Average: 3.39 (3.61)

MLB Median: 3.60 (3.58)

AL Average: 3.58 (3.71)

NL Average: 3.38 (3.53)

MLB Best/Worst: 2.69 / 4.41 (2.71 / 4.69)

Average of the Top 15 Rotations: 3.27 (3.31)

Average of the Bottom 15 Rotations: 3.69 (3.91)

MLB Range of the 11-20 Ranked Rotations: 3.64 – 3.80 (3.42 – 3.72)

Once again there was a change here, with the average improving by 22 points. The median once again stayed the same, and actually went up two points. Looking at the differences in the numbers, it seems that the biggest change came from the bottom 15 teams. The top teams stayed about the same, while the bottom teams saw improvements. The worst team in baseball was 28 points better than 2010, while the bottom 15 average was 22 points better.

#3 Starter

MLB Average: 3.77 (4.15)

MLB Median: 4.04 (4.12)

AL Average: 4.05 (4.28)

NL Average: 3.75 (4.03)

MLB Best/Worst: 3.01 / 5.27 (3.22 / 5.19)

Average of the Top 15 Rotations: 3.53 (3.73)

Average of the Bottom 15 Rotations: 4.26 (4.56)

MLB Range of the 11-20 Ranked Rotations: 3.81 – 4.18 (3.86 – 4.42)

Once again we see improvements, although this time the improvements are across the board, rather than just from the bottom 15 teams. The surprising thing here is that back in 2006, the average number one starter had a 3.60 ERA. Now, just a few points worse than that will only get you a number three starter.

#4 Starter

MLB Average: 4.32 (4.62)

MLB Median: 4.68 (4.57)

AL Average: 4.69 (4.76)

NL Average: 4.28 (4.49)

MLB Best/Worst: 3.44 / 5.89 (3.51 / 6.05)

Average of the Top 15 Rotations: 4.00 (4.20)

Average of the Bottom 15 Rotations: 4.98 (5.03)

MLB Range of the 11-20 Ranked Rotations: 4.14 – 4.36 (4.38 – 4.78)

In this case, we saw a bigger jump from the top 15 rotations. You could also expand that to the top 20 rotations, if you consider that the number 20 ranked team in 2013 had better production from the number four spot than the 20th best team in 2010.

#5 Starter

MLB Average: 5.54 (5.69)

MLB Median: 5.88 (5.69)

AL Average: 5.83 (5.68)

NL Average: 5.56 (5.70)

MLB Best/Worst: 4.15 / 7.51 (4.56 / 7.16)

Average of the Top 15 Rotations: 5.00 (5.41)

Average of the Bottom 15 Rotations: 6.39 (5.97)

MLB Range of the 11-20 Ranked Rotations: 5.45 – 6.33 (5.37 – 5.96)

Once again the results improved from 2010. However, I think the expectations are still too high for number five starters. The best team in baseball had a 4.15 ERA from their fifth best spot, but the average is a 5.54 ERA, and the average from the best rotations is a 5.00 ERA.

Dividing Lines

In his original article, Sackmann had dividing lines in his research, where he basically took the mid-point between each rotation spot to give a better idea of the range for each rotation spot.  This can also be accomplished by getting the average of all of the pitchers for each spot (for example, the mid-point for the #1/2 starters is the average of all of the #1 and #2 pitchers).  The dividing lines for 2013 (with 2010 in parenthesis):

#1/#2 – 3.21 ERA (3.36)

#2/#3 – 3.69 ERA (3.88)

#3/#4 – 4.19 ERA (4.38)

#4/#5 – 5.09 ERA (5.15)

That breaks down to the following ranges:

#1 – 3.21 ERA or better (3.36)

#2 – 3.21 – 3.69 ERA (3.36 – 3.88)

#3 – 3.69 – 4.19 ERA (3.88 – 4.38)

#4 – 4.19 – 5.09 ERA (4.38 – 5.15)

#5 – 5.09 ERA or worse (5.15+)

The quality of pitchers has gone up considerably since the original study in 2006. The dividing lines between a number one and a number two starter was a 3.87 ERA in 2006. Now the dividing lines for a number two and three starter is better than that mark.

At the same time, a back of the rotation starter still puts up an ERA around 5.00 or worse. It seems that if someone drops below a 4.19 ERA (which is the end of the range for a number three starter), he’s not considered a guy who should be in a major league rotation. A good rotation is going to have a number three quality starter at the number four spot, but is still going to have one weak starter in the rotation.

When I talk about future projections for prospects, what I’m referencing are the league averages and not where they fit in on individual teams. When I’m talking about a guy who can be a number four starter, I’m talking about an ERA in the 4.19-5.09 range. I feel like the opinion of each starting spot is usually one spot higher than the actual results. When people think about the numbers from a number four starter, they’re actually thinking of a number three starter. The numbers from a fifth starter are what people think of as a fourth starter.

Tonight I’ll take a look at what the Pirates have in their rotation, based on the above numbers.

Enjoy this story? Pirates Prospects will be switching to a subscription site on 4/13, so that we can continue bringing you the best Pirates coverage there is. For a very small monthly price, you can continue getting articles like this, along with coverage from every minor league city. Get more information here, and subscribe today!

Share This Article

Tim Williams

Tim is the owner and editor in chief of Pirates Prospects. He started the site in January 2009, and turned it into his full time job during the 2011 season. Prior to starting Pirates Prospects, Tim worked with AccuScore.com, providing MLB, NHL, and NFL coverage to various national media outlets, including ESPN Insider, USA Today, Yahoo Sports, and the Wall Street Journal. He also writes the annual Prospect Guide, which is sold through the site. Tim lives in Bradenton, where he provides live coverage all year of Spring Training, mini camp, instructs, the Bradenton Marauders, and the GCL Pirates.

Is There a Spot in the Majors For Jeff Locke?

Next Story »

Prospect Watch: Three Hits For Alen Hanson, Gregory Polanco and Stetson Allie

  • piraddict

    Great approach Tim! Thanks.
    Another idea. Is there a typical life cycle to a MLB pitcher so that for instance they might start at a 3 mature to a two and then decline to a 5 and out of the league? How does this tie to the age of the pitcher?

    • CalipariFan506

      You just described Wandy Rodriguez.

  • John Ervin

    ERA from this site? Really? How about xFIP please?

    • http://www.piratesprospects.com/ Tim Williams

      ERA and xFIP are the same when you look at the league averages over a season.

  • Andrew

    Excellent stuff, I always like to see older works updated especially given the changes in the run environment.

Latest Analysis

  • Gregory Polanco

    Q&A: Trading Prospects For Rentals, Polanco Concerns, Meadows vs Appel

    5 hours ago

    I missed the Q&A last week due to a common problem in Spring Training: I forgot what day it was. It was around 6:00 that I was ...

    Read More
  • Nick Kingham f

    Improving His Two-Seam Fastball will Make Nick Kingham a More Effective Pitcher

    1 day ago

    With Jameson Taillon returning from Tommy John surgery, and unlikely to make an impact at the Major League level early in the year, the top prospect to ...

    Read More
  • Arquimedes Caminero 3

    The Roster Situations That Could Impact the Makeup of the Pirates Bullpen

    3 days ago

    There are less than two weeks remaining in Spring Training, and the one area where the Pittsburgh Pirates had actual position battles is heating up. There were ...

    Read More
  • Jordan Luplow

    How the Pirates are Trying to Stay Ahead of the Curve With the New Draft Rules

    4 days ago

    The 2011 Collective Bargaining Agreement brought a lot of changes to Major League Baseball. The biggest change for the Pittsburgh Pirates came in the draft. From 2008-2011, ...

    Read More
  • Alen Hanson

    The Key For Alen Hanson to Help the Pirates in the Majors This Year

    5 days ago

    When the Pittsburgh Pirates moved Alen Hanson to second base last year, part of the plan was to get him to the majors faster by putting him at ...

    Read More
  • Tyler Glasnow 2

    What the Stats Don’t Tell You About Tyler Glasnow

    6 days ago

    The stat line for Tyler Glasnow’s start at Pirate City yesterday looked great: 3 IP, 0 H, 1 R, 1 ER, 1 BB, 1 K. The lone run ...

    Read More
  • JaCoby Jones Josh Bell

    JaCoby Jones Did Fine in the Move to Shortstop, But Needs to Cut Down on Strikeouts

    1 week ago

    The Pittsburgh Pirates drafted JaCoby Jones as an outfielder in the third round of the 2013 draft, then surprised everyone the following year when they moved him ...

    Read More
  • Cody Dickson is a lefty with the upside of a middle of the rotation starter. (Photo Credit: Mark Olson)

    The Mental Adjustment that Led to Cody Dickson’s Dominant 2014 Second Half

    1 week ago

    Trusting his stuff and not trying to do too much — that has been the key for left-handed pitcher Cody Dickson so far in his professional baseball ...

    Read More
  • Third Base Mathisen Luplow Joe

    Who’s on Third? In the Pirates’ Farm System, It Could Be Anyone

    1 week ago

    If you have ever played third base in your life — professional, college, high school, slow pitch softball — then the Pittsburgh Pirates might be contacting you ...

    Read More
  • Jason Creasy

    Another Pitcher to Watch From the Pirates’ 2011 Draft

    2 weeks ago

    The 2011 draft is shaping up to be a great class for the Pittsburgh Pirates. They picked first overall that year, so naturally you’d expect good things ...

    Read More
  • Browse More Articles

    More