Source: Statistics derived from information available at Baseball-Reference.com.Each franchise is identified by the nickname of its current team. Some franchises have changed cities, of course, and some teams' nicknames have changed, even when the teams have stayed put.
I chose to plot nine-year, centered W-L records for three reasons. First, a team's record over nine years should obliterate aberrations: unusually bad or good years. Second, the selection of nine years (rather than ten, for instance) allows for the computation of a centered average. Third, a centered average gives a better indication of a team's success (or failure) in the year for which the average is plotted.
I plotted the original eight franchises separately from the seven expansion franchises for two reasons. First, a graph that plots the records of all the franchises would be too cluttered to read easily. Second, I wanted to highlight the effects of expansion (if any) on the success (or failure) of the original franchises. (Note that the records of the seven expansion teams include those of the Milwaukee Brewers, now a National League team. The Brewers entered the AL in 1969 as the Seattle Pilots, moved to Milwaukee in 1970, and moved to the National League after the 1997 season. Accordingly, I computed and plotted nine-year, centered averages only for the years that the Pilots/Brewers were an AL team.)
Now, for some relevant history:
- Expansion of the AL occurred in three increments: two teams in 1961 (Angels and Senators/Rangers), two teams in 1969 (Pilots/Brewers and Royals), and two teams in 1977 (Blue Jays and Mariners). For the AL, the addition of the Devil Rays in 1998 offset the transfer of the Brewers to the NL. Expansion of the NL occurred in 1962 (Mets and Astros), 1969 (Expos/Nationals and Padres), 1993 (Marlins and Rockies), and 1998 (Brewers and Diamondbacks). Thus the number of major league teams, which had been 16 from 1901 through 1960, rose to 18 in 1961, 20 in 1962, 24 in 1969, 26 in 1977, 28 in 1993, and 30 in 1998.
- "Free agency" began officially in 1976, just before the third wave of expansion, Free agency enables a player with six or more years of major-league experience to sign with a team of his choice, following the expiration of his current contract or his current team's failure to exercise a contract-extension option.
Source: Statistics derived from information available at Baseball-Reference.com.This graph plots, for each season from 1901 through 2007, the average absolute value of the deviation of team W-L records from the league's overall record. For example, a W-L record of .400 and a W-L record of .600 both deviate by .100 from a league W-L record of .500. (The AL''s overall record was, of necessity, .500 in each year through 1996, when there was no interleague play during the regular season. Since the advent of interleague play after 1996, the overall W-L record of the AL has ranged from a low of .495 in 1997 to a high of .512 in 2006.)
It seems indisputable that baseball, represented here by the AL, has become more competitive since the advent of expansion and the establishment of free agency. (The "blip" around 2002 seems to be an anomaly caused by the confluence of several unusually abysmal and outstanding seasons.)
Why? I suggest the following:
- Expansion has not "diluted" the quality of baseball, for two reasons. First, the U.S. population of males aged 20-44 has more than tripled since 1901, while the number of teams in the two major leagues (30) is still less than double the number that existed in 1901 (16). Moreover, given the additional competition for talent since expansion, teams have become more willing to recruit players from among the black and Hispanic populations of the U.S. and Latin America. That is to say, teams have come to draw more heavily on sources of talent that they had (to a large extent) neglected before expansion. (True, it takes time for a new franchise to become competitive, but -- with the possible exception of the Devil Rays -- new franchises have become competitive, for a while, at least.)
- Free agency has made baseball more competitive by enabling less successful teams to attract high-quality players by offering them more money than other, more successful, teams. Money can, in some (many?) cases, compensate a player for the loss of psychic satisfaction of playing on a team that, on its record, is likely to be successful.
- The competitive ramifications of expansion and free agency have been reinforced by the limited size of team rosters (e.g., each team may carry only 25 players from May through August). No matter how much money an owner has, the limit on the size of his team's roster constrains his ability to sign all (even a small fraction) of the best players.