How good is "your" #4 starter?

[Eric_Davis]

There's a lot of talk lately, mostly negative, or maybe the negative ones just like to scream the loudest, about the quality of the back of the REDS' rotation.

Well, here's an article by Jeff Sackmann, the creator of MinorLeagueSplits.com and BrewCrewBall.com. He also runs the sabermetrics site BeyondTheBoxscore.com and contributes to the fantasy magazine Heater.

It's good food for thought.

About that constant negativism: Maybe you were positive at one time, and then you crossed over to the dark side, but your ego is so bent on proving yourself right that you can't help yourself anymore. So, you twist statistics to fit your negative thinking ignoring all rational thought. Everything has become black or white, no longer any room for anything in between. Bottom line is that you're missing out watching the transition from the Cincinnati REDS being transformed from one of the worst, if not the worst organization in baseball, to an aggressive, forward thinking organization that is passing other ballclubs by in terms of talent, depth, and wins. You can stop to smell the roses, or continue puking on Pete Rose Way. But, it's your loss.

Here's the article:

by Jeff Sackmann
December 27, 2006

When pundits talk about a free-agent pitcher, they often refer to him as a "#3 starter" or, say, a "#4 starter for a contender." It's common enough usage that most baseball fans know what that means, or at least know what the pundits are getting at.

Of course, this usage is extremely imprecise: one man's #2 is another man's #4, and there's no clear way to settle the debate. Taken literally, a pitcher's position in the rotation depends entirely on context: Zach Miner, the fifth-best starter on last year's Tigers, had a lower ERA than any regular starter for the Royals.

My biggest beef with this kind of talk is that it invariably overestimates just how good pitchers should be. Ask most fans to list you some #1 starters and you might get 15 aces out of them; within the 30 top pitchers in baseball, there are some names that don't seem to fit. Practically speaking, that means there aren't enough #1 starters to go around. Ignoring for the time being that Luke Hudson was the best starter on his team, that top 30 list still includes names such as John Lackey, Chris Capuano, and Jason Jennings.

Further complicating the situation is the prevalence of pitcher injuries. Ben Sheets is one of those big-name aces, but while the Brewers planned for him to be their #1 guy last year, it was more frequently Capuano at the top of the rotation. The injury effect on the entire rotation is even more dramatic: many teams have to get thirty or more outings out of replacements. For instance, John Rheinecker, Carlos Marmol, and Joe Saunders each started 13 games last year.

The result of all of those injuries: the guy you sign as your #4 starter becomes your #3 guy, and your swingman enters the rotation for a month. An above-average rotation can look outstanding if everyone stays healthy: think of the 2006 Tigers (Jeremy Bonderman, Kenny Rogers, Nate Robertson, and Justin Verlander), or more dramatically, the 2003 Mariners, for whom five pitchers started all 162 games.


Shall We Crunch Some Numbers?

To get a better sense of what we mean (or, anyway, what we ought to mean) when we talk about rotation spots, let's look at some stats. Ideally, we can come up with some numerical guidelines to easily eyeball where a pitcher fits into the average rotation.

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.

Here's how that shakes out for the Twins staff:

Starter GS ERA
Liriano 16 2.16
Santana 16 2.77
#1 Total 32 2.47

Santana 18 2.77
Bonser 14 4.22
#2 Total 32 3.40

Bonser 4 4.22
Radke 28 4.32
#3 Total 32 4.31

Garza 9 5.76
Silva 23 5.94
#4 Total 32 5.89

Silva 8 5.94
Baker 16 6.37
Lohse 8 7.07
#5 Total 32 6.88

Boof Bonser is a #2/#3 starter? Matt Garza a #4 guy fresh up from Triple-A? On the Twins staff last year, that was the case.

(A side note for those of you interested in methodology: I didn't use play-by-play data for this analysis, so I don't have each pitcher's precise numbers as a starter. For the vast majority of pitchers, that's not an issue, but for guys like Kyle Lohse, who made nine starts and 13 relief appearances, it gets tricky. For pitchers who made a start but made more appearances in relief, I estimated their starter ERA on the assumption that they averaged five innings per start and had an ERA exactly one run higher in the starting role. Using that technique, I estimate Lohse's starter ERA at 7.47. Thus, in the complete table below, the Twins numbers are slightly different.)


The Results Are In

After going through that procedure for all thirty MLB teams, we can make some generalizations. To start with, here are the averages for each rotation position:

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

What immediately jumps out at me is how high the #4 and #5 ERAs are. If there's one thing most people agree on when they talk about rotation spots, it's that a guy with an ERA over 5.00 ought to be your #5 starter. As it turns out, fewer than half of major league teams could claim an ERA under 5.00 from their #4 spot.

In fact, only three teams in baseball got an ERA under 5.00 from their #5 spot: the Tigers (4.48), the White Sox (4.99), and the Padres (4.91). And if we adjusted for park, the Padres would sneak over 5.00. Only two other teams--the Giants (5.18) and the A's (5.16) are under 5.50 from that position. Given the enormous difference between the best teams and the league averages, it's all the more apparent just how valuable rotation depth can be.

To address the issue I raised at the outset, we can use these averages to come up with rough dividing lines between rotation spots. Armed with this data, you can take any pitcher's ERA and eyeball where they would fit in to the average team's starting corps. For instance, in the table below, if a pitcher is between 3.87 and 4.36, he is, on average, a #2 starter.

Spot MLB AL NL
#1/#2 3.87 3.97 3.78
#2/#3 4.36 4.41 4.31
#3/#4 4.84 4.84 4.84
#4/#5 5.67 5.66 5.68

In other words, an AL pitcher who managed an ERA under 4.00 over 32 starts very likely qualifies as an ace. To take a few examples: Jason Schmidt is the "average" ace; a fringey #1 guy is Dontrelle Willis; an average #2 starter is Matt Cain, and the protoypical #4 is Luke Hudson. The rotation that was closest to major league norms was Milwaukee's.

For those who are interested, here are last year's complete results for all 30 major league teams:
Team #1 #2 #3 #4 #5
ARI 3.10 4.20 4.60 4.90 6.39
ATL 3.49 3.98 4.76 4.95 6.88
BAL 3.76 4.72 4.94 5.71 8.45
BOS 3.84 4.54 4.92 5.15 6.95
CHA 4.28 4.52 4.54 4.85 4.99
CHN 3.33 4.25 5.02 5.78 7.40
CIN 3.30 3.72 4.60 5.27 6.34
CLE 3.27 3.99 4.33 4.72 5.63
COL 3.78 4.15 4.24 5.45 6.00
DET 3.64 3.84 3.85 4.07 4.48
FLA 2.96 3.65 3.99 4.58 6.56
HOU 2.55 3.26 4.20 5.26 5.92
KC 4.96 5.49 5.70 6.05 7.32
LAA 2.97 3.58 3.91 4.42 5.68
LAN 3.52 3.76 4.34 4.65 5.75
MIL 3.86 4.11 4.50 4.88 6.21
MIN 2.47 3.41 4.32 5.84 6.51
NYA 3.52 3.63 4.34 4.93 6.44
NYN 3.72 3.97 4.41 5.02 6.55
OAK 3.83 4.10 4.58 4.87 5.16
PHI 3.91 4.12 4.82 5.38 6.92
PIT 3.99 4.59 4.75 5.17 6.30
SD 3.41 3.64 3.78 4.22 4.91
SEA 4.22 4.49 4.52 4.67 6.03
SF 3.59 4.18 4.72 4.95 5.18
STL 3.09 4.12 5.10 5.68 6.59
TB 3.39 4.47 4.95 5.32 6.85
TEX 4.41 4.51 4.78 5.63 6.21
TOR 3.19 4.11 4.49 5.06 6.44
WAS 4.64 4.96 5.27 5.58 6.23

[BRM]

At a quick glance, it looks like 19 teams got better performances from their #4 than Cincinnati did last year. And Eric Milton is the Reds #4 this year. Yippee!!

On the bright side, I'd expect the Reds to cut bait with him at some point thus moving them up the list. Hopefully guys like Belisle and Saarloos can improve the back end of the rotation.

[coachw513]

Great article and post

The key is relativity...our rotation isn't that great and is very shaky at the back end...BUT RELATIVE TO ALL OTHERS (my point when I attempted a week ago to rank the NL Central rotations) is that the Reds' rotation is comparable to the others in this division, and based on the above, is comparable to most others in baseball...

It comes down to health and depth...we cannot predict health, but the Reds staff is clearly deeper and more talented than the past few years...will it translate into more victories, who knows

Clearly, though it's more fun to debate Milton, Livingston, Belisle, Saarloos, Ramirez and Santos over the names of earlier this decade (due to this being a family-oriented site, I will refrain from using those names here )

[Eric_Davis]

Part two of this article is posted below......

Another Look at Starting Rotations
by Jeff Sackmann
January 17, 2007

My pair of articles on starting rotation slots last month found a lot of readers, a lot of criticism, and a lot of misunderstanding. My analysis (along with Chris Jaffe's, published at about the same time) looked at past data and determined—post facto—how rotations performed.

What these articles did not do was retain the standard usage of starter numbers. For instance, in the way we normally use the term, the "ace" of the 2006 Brewers on Opening Day was Ben Sheets. By the end of the season, the top performer had been Chris Capuano. In an effort to describe what happened in groups of 32 starts, my approach had to combine the two; Sheets had the better ERA, but he only logged 17 starts.

That method has little predictive value, but dramatically illustrates the effect of injuries.

To recall, here were the ERAs amassed by the average MLB team's first through fifth groups of 32 starts:

#1 #2 #3 #4 #5
3.60 4.14 4.58 5.10 6.24

In many teams' cases, it wasn't that their "#5 starter" turned out to be dreadful. Instead, because one or more starters got hurt, they were forced to turn to a sixth, seventh, or worse option.

This table illustrates the point, showing the number of teams who require any given number of starters.

Starters Teams
7 1
8 2
9 4
10 7
11 4
12 8
13+ 4

The White Sox were the most fortunate (or prescient, or skillfully managed—take your pick), using only seven starters. The Royals, by painful contrast, needed 17. Most teams used between 10 and 12.

For the vast majority of clubs, this meant that the #1 through #5 labels assigned in Spring Training quickly lost meaning.

Here's another way of looking at it: this second table shows the number of teams that got any given number of starts from the five pitchers who started the most games:

Starts Teams
<=100 1
101-110 2
111-120 7
121-130 6
131-140 8
141-150 4
150+ 2

Even that presentation is somewhat misleading. By including the five pitchers who started the most games, it might not be considering the "starting five" for each team. A single rotator cuff tweak or popup-chasing collision can result in #6 getting 25 starts, much to the chagrin of millions of Aaron Sele-hating fans.

In short, there's a big difference between the way we commonly use terms like "#3 starter" and the way I tried to redefine it (the third-best 32 starts) in my previous articles. To create a model that has more predictive value, we need to get closer to general usage.


The Model

To do so requires deciding who the official starting five or six was for each team entering the season. That's necessarily approximate, especially in situations where a team had to start the campaign with a replacement (for someone like Sheets or Roger Clemens) but nonetheless planned on getting that preferable starter back.

In order to come up with some version of MLB rotations, circa March '06, I went through a variety of sources and established each team's #1 through #5 starters. I didn't rely on anecdotal evidence to assign numbers to each starter, just to decide who made up each team's first five. I tried to stick as closely to that evidence as I could, but I didn't count pitchers who were slated to be in a rotation but got hurt before they made more than a start or two, such as Zack Greinke and Shawn Estes.

To assign numbers to each starter, I took the top five and ranked them by 2006 ZiPS ERA. For instance, in the case of the Cleveland Indians, it was clear enough that they started the season with Paul Byrd, Jason Johnson, Cliff Lee, C.C. Sabathia, and Jake Westbrook.

They sorted out as follows:

# Starter Z-ERA
1 Sabathia, CC 3.79
2 Byrd, Paul 3.90
3 Westbrook, Jake 4.02
4 Lee, Cliff 4.30
5 Johnson, Jason 4.59

This way, the #1 starter was determined by an objective predictor of skill, not a mishmash of opening day starting assignments.


The Sixth Man

The trickiest thing to determine using pre-season evidence is the #6 starter. In fact, it's not only difficult, but probably worthless. While each team may well enter the season with a sixth starter in mind, the situation could be very different just a few weeks later. To take one example: the Brewers initially planned on using Rick Helling first if another starter was needed. But due to injury and ineffectiveness, Milwaukee used several pitchers before Helling finally got a big-league start.

In short, I'm convinced there's no single right way to pick a sixth starter. I went about it—in most cases, anyway—by selecting the pitcher who started the most games but wasn't part of the initial starting five. This resulted in choosing guys such as Elizardo Ramirez, Jeremy Sowers, Zach Miner, and Cole Hamels. It passes the sniff test, so the league averages will give us a reasonable approximation of who teams called upon the most when needed.


Finally, the Numbers

Using this model, here is the average starter in each of the first six rotation spots:

Spot ERA GS IP
#1 Starter 3.91 28.5 181.2
#2 Starter 4.61 26.6 165.7
#3 Starter 4.74 27.6 167.5
#4 Starter 4.82 20.8 123.4
#5 Starter 4.96 20.6 126.8
#6 Starter 4.77 15.5 95.1

The average rotation got 124 starts out of its front five and another 15 from its top replacement, leaving 22 more for the rotating back end that most teams employed. The biggest difference is between the #1 and #2 starters, suggesting why having two aces catapults a team so far ahead of the pack.

Notably, the number of innings and starts takes a big drop after the #3 spot. That's not so much due to injury, I suspect, as ineffectiveness. (The two, of course, are not wholly unrelated.) Especially in the #5 position, pitchers are hardly guaranteed their spot for as long as their arm stays attached.


The Sixth Man, Again

The most striking thing in this data is that the average #6 starter is nearly as good as the average #3 starter. Upon reflection, though, it begins to make sense. As I suggested in discussing the difficulty of choosing a sixth starter, there's plenty of bias there.

If Hamels had been ineffective in Triple-A, he would've been passed over for someone else. If Miner had gotten shelled in his first few big-league outings, a la Hayden Penn, he would've gone right back to Toledo, and we'd be using Wilfredo Ledezma in this sample instead. Despite the selection issues, there's a lesson here: the teams with the best sixth starters were the ones with large pools to choose from.

Francisco Liriano had a freakishly good season for a fill-in, but the Twins could also haved turned to Matt Garza or Boof Bonser. Scott Olsen was another superb #6, but the Marlins had more good young pitching last year than the rest of the NL East combined. I don't mean to take anything away from Liriano or Olsen, but the Twins and Marlins set themselves up to get good performances from their #1 fill-in, even if they didn't know exactly who would end up starring in that role.


Predict Away

This set of numbers, unlike the group I produced in my previous rotation analyses, are ones you can compare to projections for specific players. Keep in mind, though, that these aggregate ERAs are for a pitcher in a neutral park against average opposition—not precisely the case in very many instances.

One important way in which these conclusions dovetail with those of my previous articles is just how much teams have to rely on starters beyond their first five. The average team gets nearly 25&#37; of its starts from pitchers who don't start the year in the rotation. Taking proper precautions to avoid disaster in those 30-40 starts can be just as important as making marginal improvements in the middle of your rotation.

[Eric_Davis]

I apologize for the mixup in order here. Above was part III, and below is part II of the series on back-of-the-rotation articles.

So, Here's part II....

More Fun With Rotation Numbers
by Jeff Sackmann
December 29, 2006

My article on Wednesday, How Good Is Your #4 Starter, presented some counterintuitive findings on starting rotations, such as—big surprise—how good an average #4 starter is. Due to injuries and the related fact that the guy who starts the year as your #5 starter often ends up in the middle of the rotation, teams rarely get the production they predict out of each rotation spot.

These calculations don't hold the key for any breakthrough new approach to roster construction, but they do illustrate some of the ways in which good (or lucky) teams are different from bad ones. With that in mind, let's look at a few ways in which teams set themselves apart last year.


Rotation Spot Rankings

Here are the teams who had the best and worst performances from their "#1 starters" last year. Remember that in some cases, a team's #1 starter is a composite: it's defined as 32 starts from the team's one, two, or possibly three best starters.

Team #1 ERA
MIN 2.47
HOU 2.55
FLA 2.96
LAA 2.97
STL 3.09
…
SEA 4.22
CHA 4.28
TEX 4.41
WAS 4.64
KC 4.96

Both of our top two teams got substantial help from part-time pitchers: the Twins benefited from Francisco Liriano's 16 starts, while the Astros took advantage of their half-season from Roger Clemens. On the bottom of this list, there's one surprise: while the White Sox had one of the most balanced rotations in baseball (as we'll see in a moment), no one stepped up as their 2006 ace.

Now for the best and worst rotation middles:

Team #3 ERA
SD 3.78
DET 3.85
LAA 3.91
FLA 3.99
HOU 4.20
…
TB 4.95
CHN 5.02
STL 5.10
WAS 5.27
KC 5.70

Even after accounting for the pitcher-friendliness of Petco, it's impressive that the Padres got nearly 100 starts with a total ERA under 3.80. It may be a bit more surprising to see Florida on this list, but their core of rookies and Dontrelle Willis came through in a big way.

Finally, the best and worst in the #5 spot. Remember that, especially at the bottom of this list, these numbers are often the result of mixing and matching after a manager loses a front-line starter or two to injury.

Team #5 ERA
DET 4.48
SD 4.91
CHA 4.99
OAK 5.16
SF 5.18
…
PHI 6.92
BOS 6.95
KC 7.32
CHN 7.40
BAL 8.45

Hayden Penn, we're looking at you. It amazes me that there's a four-run difference between the best and worst teams on this list; if you figure that each outing from a fifth starter lasts about five innings (a tenuous assumption, when a pitcher is giving up a run an inning), that's a difference of about 70 runs over the course of the season. Seventy runs!

On another note, what was particularly impressive (or lucky) about the Tigers' performance here is that it was patched together from several pitchers, most notably Zach Miner and Wilfredo Ledezma. It's one thing to get 32 strong starts from your #5 starter if no one gets hurt; it's yet another to patch together a group that outperforms the majority of #3 starters.


Distribution

It seems to me that an "even" rotation is a good one, both in the sense that your team is better off with #4 and #5 guys in the vicinity of league average, and because it would more consistently distribute the burden on your bullpen. One way to measure that is to take the standard deviation of each team's five rotation-spot ERAs.

The best and worst are as follows:

Team STDEV
CHA 0.28
DET 0.32
OAK 0.54
SD 0.59
WAS 0.61
...
FLA 1.37
HOU 1.39
CHN 1.55
MIN 1.67
BAL 1.78

Indeed, most of the teams at the top of this list are good ones; however, the Nationals sneaked onto the board with their thorough mediocrity. The bottom of the list is a reminder that the distribution doesn't matter much: many of those teams have a high standard deviation because their #1 pitcher is so good, not just because the back end is iffy.


What About Good Teams?

Even when speaking in the most general sense, people differentiate between a #3 starter on a good team and an equivalent rotation slot on a bad team.

To try to pinpoint just how different those numbers are, here are the averages for the top half of pitching staffs in baseball last year:

Lg #1 #2 #3 #4 #5
MLB 3.30 3.83 4.30 4.87 5.94
AL 3.27 3.81 4.26 4.84 5.76
NL 3.32 3.85 4.33 4.88 6.09

It continues to amaze me just how bad these #5 slots are. We all watch our favorite teams eke out one too many starts from, say, Ben Hendrickson or Jeff Karstens, but it has never seemed to me like back-end starters are so thoroughly horrible. What also comes as a surprise is that there's no single place or two in which good teams outperform the average. The better staffs have slightly better back ends and somewhat superior front ends as well.

Another way to look at this would be to figure the averages for last year's playoff teams. Of course, playoff teams needn't have great pitching staffs; some of them aren't even in the top half of their league.

Here are the results for those eight squads:

Lg #1 #2 #3 #4 #5
MLB 3.40 3.81 4.34 4.91 5.80
AL 3.36 3.75 4.27 4.93 5.65
NL 3.43 3.87 4.41 4.89 5.95

There's not much of a difference between this table and the previous one; the one slight exception is for #5 starters. While the rotations, overall, are a bit worse than the average of the top half of MLB teams, the worst 30 starts are a bit better. I don't know if there's anything to make of that, or if it's the result of a small sample and a tremendous Tigers rotation.


By Way of Conclusion...

Over the last few years, we've heard more and more general managers acknowledge the need to go into the season six, seven, or more starters deep; a great example of that is the Brewers, who just signed Jeff Suppan.

One could make an argument that the Brewers' rotation was set, with Ben Sheets, Chris Capuano, Dave Bush, Claudio Vargas, and Carlos Villanueva. It wouldn't have been a great rotation, but if everybody stays healthy, those hurlers could give you a credible fivesome for 150 or more games. But, of course, the odds of that are tiny. When Villanueva (or Darrell Rasner, or Brad Hennessey) becomes your sixth man, your chances of suffering a 6.00 ERA over 30 starts goes down substantially.

If there's one thing this analysis suggests, it's just how common that painful outcome is. If, as I suggested on Wednesday, your #4 starter isn't as good as you thought, that goes double for the guys who pitch the following day.

[Redsland]

Maybe you were positive at one time, and then you crossed over to the dark side, but your ego is so bent on proving yourself right that you can't help yourself anymore. So, you twist statistics to fit your negative thinking ignoring all rational thought.

You posted a lot of words after these, but this is where I stopped.