*ad infinitum*.

- Rule 1: In selecting the greatest pitchers of all time, you DO NOT TALK about the greatest pitchers of all time.

- Rule 2: You must have statistical evidence to back up your picks.

- Rule 3: You must include, or at least consider, pitchers from all eras of baseball.

- Rule 4: At least two lefties must be included in the final rotation.

**Statistics to be Considered**

The importance of ERA and ERA+

Pitching statistics are not quite as complex as hitting statistics, in that baseball statisticians have generally accepted that a few key categories are important in determining the overall value of a pitcher. While wins, complete games, strikeouts, walks, hits, or any combination of such factors can paint a basic picture of how good a pitcher is, there is no more revealing stat than his Earned Run Average (ERA). As you probably know, ERA is calculated by dividing innings pitched by earned runs, and multiplying the quotient by nine.

ERA is one of the most accurate and straight-forward statistics in all of sports. Very few other calculations exist that are able to show just how significant a single player was to the outcome of the games he took part in. However, while the ERA of a pitcher can tell us an awful lot, using it as the sole indicator of his value leaves an extremely important question unanswered: how many runs were being scored on average during the season or career in question?

After all, the prevailing trend in offensive productivity during a certain period in baseball history surely can have a dramatic effect on the ERA of any given pitcher. Mordecai Brown's career ERA of 2.06 seems breathtaking at first glance, but somewhat less extraordinary when you consider that the league ERA over the course of his career was 2.85. On the other hand, Randy Johnson's career ERA (through 2005) of 3.11 seems particularly impressive when you consider that the league average during that span was 4.43.[1]

A statistic called ERA+ takes this generational fluctuation into consideration. ERA+ is calculated by dividing the league-average ERA by the ERA of the pitcher in question. To convert the resulting percentage into an actual number, the quotient is then multiplied by 100. Thus, an ERA+ of over 100 would mean above-average performance, while an ERA+ of under 100 would be below-average. By way of example, Fergie Jenkins posted a career ERA of 3.34, while the average of the league throughout his career was 3.85. By dividing 3.85 by 3.34, then multiplying by 100, we find out that his career ERA+ was 115[2].

Because ERA+ can be calculated for either a single season or over an entire career, it is valuable in determining pitching greatness in two different ways. First, it can show us how a pitcher performed relative to his contemporaries throughout his career. For instance, any pitcher who doesn't have a career ERA+ of 100 or better is not worth considering for our list. Since such a pitcher is essentially below-average, they should have no place among the all-time greats.

The second way in which ERA+ is valuable is in showing the dominance of various pitchers for short periods of time. After all, it is very difficult to compare pitchers' individual seasons when the nature of pitching has changed quite significantly over the years. Is Greg Maddux's 1995 season comparable to Walter Johnson's performance in 1913? Upon first glance, the answer seems obvious: Walter Johnson went 36-7 with an ERA of 1.14 in 1913, while in 1995 Maddux posted a record of 19-2 and an ERA of 1.63. It may appear that Johnson's season was far more impressive, but a closer look reveals that Maddux had the same ERA+ in 1995 as Johnson did in 1913.[3] This is due to the fact that 1995 was a year for hitting, while 1913 is a year that falls within the period commonly referred to as the "Dead Ball Era."

Still, it would be unwise to conclude that Maddux's and Johnson's seasons rank equally simply due to their identical ERA+ figures. "How much lower than a 1.14 ERA can you really expect a pitcher to go?" say the Johnson defenders. "And, while we're at it, what kind of supporting cast did the Big Train have? Surely you can't compare the Braves of the nineties with the Senators of the Dead Ball Era?"

"But Johnson never pitched at night, and played in an all-white league," retort fans of Maddux. "And when did Johnson ever face a juiced-up, weight lifting giant?"

Such arguments are perfectly legitimate. ERA+ is a lot of things, but it is not the Holy Grail of pitching statistics and cannot single-handedly determine the best pitchers of all time. However, it does provide us with a good place to start, and (along with ERA) is a statistic that will come up continually throughout our analysis.

Wins, Strikeouts, Hitting and Fielding: Yea or Nay?

Because ERA and ERA+ are imperfect measuring sticks, we now must determine which other statistics or intangible factors are also worth considering in our analysis. Many baseball-nerd types would argue that statistics such as win-loss record, strikeouts and no-hitters are truly irrelevant to the value of a pitcher and should not be considered. On the other hand, old-time classicalists would probably assert that no examination of Major League pitching would be complete without taking such celebrated numbers into consideration.

When it comes to this particular discussion, one can only assert a personal opinion on the matter, since any attempt of objectivism at this point would probably be in vain. I essentially feel that both sides have good points; while it is true that ERA and its cousin ERA+ are generally more telling factors in determining pitching excellence, statistics like win-loss record can show us things that these more precise calculations cannot. Put another way: if two pitchers have the same ERA in the same season, how would you determine which had the better year?

My answer is win-loss record. While it may very well be an overrated and overused statistic, it is still significant enough to consider in a historical analysis of baseball pitching. Perhaps a pitcher gives up few earned runs on average; but how effective is he in leading his team to victory? After all, the ultimate goal of any team sport is a "W."

Thus, dismissing win-loss record from our analysis would essentially mean conceding that baseball is a completely individualistic sport. Relative to other major sports, baseball indeed relies more heavily upon the performances of individuals. However, to deny that certain players mean more to their teams than others for reasons beyond their individual statistics seems like quite a stretch.

For all of these reasons, win-loss record will be a factor in our analysis, though it will not be given as much weight as ERA or ERA+. Further, a player's win-loss record will be considered in the context of whom he pitched for and when he pitched. For example, if pitchers before 1900 routinely threw as many as 60 games per year, any pitcher from this era who is worth considering better have at least a couple of 40-win seasons. Or, if a pitcher's team goes 100-62, and he wins 80% of his games, he will not necessarily be favored over a pitcher whose team goes 62-100 but manages to win half of his starts.

As far as other possible statistics go, strikeouts, while flashy and fun, are useless to us for the purpose of selecting the game's all-time greats. Such statistics or records may be mentioned occasionally in our analysis, but should be taken with a grain of salt when it comes to selecting an all-time rotation. Ultimately, a pitcher's job is to get an out, and it matters little if it comes by way of strikeout, pop-fly, or line drive. Walks and Strikeout/Walk ratio are other examples of useless statistics that we should avoid placing much emphasis upon. Why should a pitcher be advantaged in our analysis if runners get on base via singles rather than walks?

In summary, the statistics we should use for a study that will attempt to determine the greatest pitchers of all time must illustrate how good a particular pitcher was at preventing runners from crossing home plate and winning ball games. ERA, ERA+ and, to a lesser extent, win-loss record are all statistical categories which provide vast insight into such a topic, while walks and strikeouts provide little. In a case where two pitchers seem so comparable that we cannot determine a clear superior through examining these three statistics, less precise factors such as post-season performance, hitting and fielding ability or Cy Young Awards may also be considered.

Roadmap for the Analysis

The final five-man rotation upon which we will eventually arrive is not going to come overnight. That being the case, it is necessary to have some kind of a game plan as to how we will go about achieving our final goal.

Since baseball has been around for over 100 years, it is necessary to break its history down into specific time periods when doing a broad analysis such as this. By determining the most dominant pitcher(s) of each era, we can then narrow the list of nominees down to a reasonable amount of names. Only after this period-by-period analysis should we attempt to determine which of these domineering aces were the best.

As such, I will be dividing our analysis into eight different periods of baseball history. The exact years of each period are somewhat arbitrary, but I have generally attempted to make our study cover spans that are unique for some reason or another. For instance, I don't think it wise to group the 1980s and 1990s together, since each decade clearly has very different characteristics (the 80s was a small ball decade while the 90s was a big ball decade). I did, however, group some decades together in order to make our job easier. Thus, we will seek out the best pitchers from each of the following historical periods: 1871-90, 1891-1903, 1904-19, 1920-39, 1940-59, 1960-69, 1970-89, and 1990-present.

Through careful examination, we will (hopefully) be able to determine the most dominant pitcher from each of these eight time periods. Figuring that on at least a couple of occasions it will be nearly impossible to choose a single great, in the end we should aim to have ten Major Leaguers up for consideration. Then, to give them their fair place in history, we will take a stab at selecting the two greatest Negro League pitchers, bringing our list of aces up to twelve. At that point, the only thing left for us to do will be to cut that list down to five pitchers, who collectively will make up the all-time rotation. Dear Watson, there is work to be done!

The Task Ahead

Ready to take a walk down memory lane? Ready to revisit the greatest aces from your childhood, your father's childhood, and your grandfather's childhood? Ready to call ESPN's "50 States in 50 Days" the worst sports television special in the history of broadcasting? Me too. So instead of watching another 300-pound hick devour a cherry pie, let us put our efforts into a far more entertaining venture: comparing and contrasting pitchers of old and new.

But be forewarned: while you may be familiar with a lot of the pitchers we will be discussing, many of them have been long forgotten in the annals of baseball history, and are currently practicing on a make-believe cornfield in Iowa. So be sure to keep an open mind, or you may very well overlook one of those truly fine pitching specimens hiding among the crops.