Along the lines of a similar thread asking why the glut of home run records in baseball, I ask why the post-1994 glut of record setting winning percentages in baseball, especially in the American League. Since 1994 the 1995 Indians posted at 100-44 record, winning percentage of .694 in a strike-shortened season, the 1998 Yankees went 114-48, winning percentage of .704, and through 10/3/01 the Mariners are 112-45, with a winning percentage of .713. Historically speaking, these are extremely high winning percentages. What gives?
All AL teams since 1995 have gotten to play the post-1995
Baltimore Orioles, boosting all totals by a few wins per team.
Seriously, I don’t have time to look this up, but what are
records for interleague play, which began in '95? Does the
AL have a statistical advantage?
Between 1901 and 1995 (inclusive), twenty MLB teams had winning percentages of .682 or better. Six of these occurred in the first decade of the century, three in the second decade, two in the 1920s, three in the 1930s, three in the 1940s (the 1942-1944 St. Louis Cardinals), and two in the 1950s. None occurred in the 1960s, 1970s, or 1980s, and only the Indians’ 1995 season in the 1990s. Since then there’ve been two more, as mentioned in the OP (NY 1998, and Seattle this year). So it happened 18 times in 50 years, then happened twice in the next decade, and then didn’t happen at all for forty years (1954 to 1995). Finally, it happens three times in seven seasons (95, 98, 2001).
My inclination is to say that the rise of the farm system and the institution of the amateur free agent draft narrowed the talent discrepancy between the best and worst teams in the 1955-1995 years, and that over the last decade or so the resource gap between the richest (and most successful) teams and the poorest (and weakest) teams has been widening. I don’t know of any objective way to measure either of these factors, and the temporal correlation between full implementation of farm systems through the sport and the beginning of the era of relative parity is tenuous at best. I will point out that the distribution of the twenty worst MLB seasons by winning percentage (again, for the years 1901-1995) is distributed through the decades in a way similar to the twenty best. I’m too tired to figure out whether we’ve seen the same sort of increase in really bad (sub .300 winning percentage) teams recently, but my impression is that we have.
That doesn’t go a long way towards explaining the 2001 Seattle Mariners, a team so rich that they have been forced to allow their three best players to go elsewhere in a span of three years - Johnson, Griffey, and Rodriguez.
I have a suspicion that the sudden appearance of the '95 Indians, '98 Yankees and '01 Mariners is a sheer fluke. In 2000, there was no team over .600 or below .400 - an unprecedented occurrence. I think we’re just lucky that we’ve seen some really good teams recently. I also suspect that the '95 Indians, '98 Yankees and '01 MAriners are all a little lucky, too - they all won substantially more games than would be expected by their rusns cored and allowed, while, for isntance, the 1975 Reds (108-54, missing the .682 cutoff) were lucky by one game at most, and really were every bit as good as the recent great teams.
You’re probably right (if not, it’d be one of the very few times I can think of that you’ve been wrong about a baseball matter). As I meant to say, there’s not a lot of evidence to support any conclusion I can come up with about the data.
Speaking of my data, it was substantially wrong. I won’t go into the details (I’ll simply plead fatigue and and some invalid asssumptions), but I will provide better information.
Only 13 teams have had a regular season winning percentage of .682 or better (not twenty as I claimed last night). The top twenty winning percentages between 1900-1999 are all .673 or better. These are distributed as follows:
1900-1909: 6 (before the Yankee's 1998 season, it would have been 7:
in 1909 the Cubs' 104-49 record was second to the Pirates' 110-42 in the NL)
1910-1919: 3
1920-1929: 2
1930-1939: 3
1940-1949: 1
1950-1959: 2
1960-1969: 1 (the 69 Orioles)
1970-1979: 0
1980-1989: 0
1990-1999: 2
Perhaps more to the point, these seasons do seem to cluster; there was a .673+ season posted in eight out of eleven years from 1902 through 1912, none for six seasons until 1919, another gap of seven years until 1927, then another burst of four within six seasons from 1927 through 1932, a six year gap, two in the next four seasons (1939 and 1942), none for over a decade until the Dodgers and Indians consecutively in 1953 and 1954, a fourteen-season gap until the 1969 Orioles, a sixteen season gap until the 1995 Indians, and then the 1998 Yankees and 2001 Mariners.
If you broaden the sample somewhat to include all teams above an arbitrary percentage, instead of an arbitrary number of teams, you find that 43 teams have posted winning percentages of .650 or better (106 wins in a full 162-game season, 101 in a 154-game season). The distribution is as follows:
1900-1909: 7
1910-1919: 7
1920-1929: 3
1930-1939: 8
1940-1949: 6
1950-1959: 4
1960-1969: 2
1970-1979: 2 (including the Big Red Machine)
1980-1989: 1 (the '86 Mets)
1990-1999: 3 (adding the 1998 Braves' .654 to the '95 Indians and '98 Yankees)
Obviously, .650+ seasons haven’t happened as often in the last fifty years as they did in the half-century before (12 times, excluding this year’s Mariners, as opposed to 21 times). But if you take the final forty years of the 20th century (1960-1999), it happened an average of twice per decade, so it’s not that far from the average that it happened three times in the 1990s, and you can’t conclude anything from the Mariners performance this year about what’ll happen over the next eight years. Given that the best seasons have historically come in clusters, it perhaps shouldn’t surprise us that we’ve seen several in recent years.
(The data above comes primarily from the electronic version of Macmillan’s Baseball Encyclopedia, which covers 1876-1996. For post-1996 information, I’ve relied on other online sources, including the Baseball-Reference.com site.)
Poking around in the data from rackensack’s research, it is interesting, and cautionery for Seattle fans, that even in pre-wild card baseball having an extremely high winning percentage is no guarantee of winning the World Series. I note that the '95 Indians, '98 Braves, '69 Orioles, '54 Indians and '53 Dodgers, as well as the 1906 Cubbies, all lost the series.