Why it is Difficult to Compare Baseball Players of Different Eras

Over the years, there have been changes to the rules of the game of baseball to enhance run productivity and to address other conditions within the game. There have been new teams and new ballparks added to the mix. We're all familiar with the hints, allegations, and things left unsaid surrounding chemical enhancement of players. Baseball has integrated, and indeed expanded its recruiting scope outside the US. Descriptive statistics of the game have been altered and in some cases newly created. It is clear that baseball in the 21^st Century looks very different from the game played at the turn of the 20^th Century. What often gets overlooked is the structure of the game itself when comparing statistics across the ages.

For about 70 years, baseball featured a championship of the two teams that finished atop their league with the best record. In 1969, Major League Baseball reorganized it's expanding leagues into two divisions each and created a league championship between the champions of each division. The winner of each League Championship won the right to represent the league in the World Series. In 1994, baseball further realigned it's leagues into three divisions and created a second tier of playoffs.

Baseball, under threat of the creation of a third major league, expanded for the first time by adding teams in 1960 (the LA Angels and Washington Senators) and again in 1962 (Houston Colt .45s and New York Mets). With this expansion, came the expansion of the number of games comprising a "season" - from 154 to 162.

So from 1904 until 1961, the champion of the league was the best of 8 teams which played 22 games against each of its 7 opponents. There was on exception, of course. In 1919, due to World War I, the season was contracted to 140 games, with only 20 games played between opponents. In 1961, the 162 game season was put into effect in the American League and the National League in 1962, thus increasing the number of games in a season by more than 5%. The expansion of the regular season with the expansion of the number of teams meant that each team would face each other 18 times during the course of the season.

In 1969, with the realignment into divisions, the format of those 162 games changed as well to 18 games with the 5 opponents in the same division and 12 games each with the teams in the opposite division. As each league expanded, the format changed accordingly until 1993 for the 1994 season (a season cancelled mid-way through due to a player strike) and again in 1997 when "inter league" play was introduced, ending a 90+ year practice of keeping the leagues separate until the World Series.

The first effect felt from these changes happened in the first year changes were made - 1961 - when Roger Maris hit 61 home runs in a season, the sixty first coming in the 162 game of the season. While there was never an asterisk associated with this feat officially, in the lore of the game the mark was represented as "61*."

When placed in context, then, there is more baseball being played now in the major leagues than there ever was, allowing more players a greater opportunity to achieve the statistical anomaly that is a Major League Record. There are more opportunities to achieve a rarity - if an event is repeated multiple times, the likelihood of a statistically rare occurrence increases (i.e. if an event could be expected to occur 1 of 1000 times, with double the teams now in existence as there were in 1901 and 8 more games played by each team, one could reasonably expect a more frequent occurrence of the rare event). Of the 17 perfect games in major league history, only 6 occurred prior to the 162 game schedule and to expansion.

While this doesn't diminish the historical records of the game, it does make their comparison sketchy. Over the years efforts to control extraneous variables between players of different eras have been made, but ultimately what is left on the field is the official record.

The champion of the American League and of the National League, no longer has to be the best in their respective league, they have to be the best in their division. Baseball statistics are based on a seasons worth of work, but because they're aggregated numbers, it is difficult to project what performance might look like in the playoffs. In the 2006 World Series, the St. Louis Cardinals won the championship of the world despite only having won 83 games - the worst record ever for a world champion. There were four teams in the National League with better records that year, meaning in the original Championship format, the Cardinals would have been watching from a far. To wit, The Philadelphia Phillies had a better record than the Cardinals, but because the Cards won the Central division, they got a playoff spot; the Philies won more than the Cards, but less than the Wild Card winner Dodgers, so they sat out the tournament.

While it sounds like an amazing achievement for an organization well over 100 years old, the fact Red Sox manager Terry Francona is the first person in his position to take the team to four post seasons isn't as impressive as it might sound - there have been 5 managers of the Red Sox since 1995, two of whom served 1 year or less during this time frame and 1 who served 2 years. This means, he is one of two people (Jimy Williams) who had the possibility of reaching the playoffs with a wild card - which Francona's Red Sox have done each time he's reached the playoffs.

What would Babe Ruth have been able to do with the bat had he 8 more games a season to play over the course of his 20+ year career? This would be almost an entire season more (160 games) with which to increase his totals. What would have been the effect of the Wild Card in 1978, when the Red Sox and Yankees were forced to play a playoff game to determine the Champion of the American League East? What would have been the effect of the unbalanced schedule currently in effect - created out of the three division alignment - on that race?

Much like the difference between a 1903 Ford "Model T" to a 2007 Ford Taurus, the game of baseball has evolved into something resembling the original game in essence, but not in actual execution. Without statistical manipulation - and arguably even with it - the differences in the game are wide ranging, making any meaningful comparison exceedingly difficult, unintuitive and , frankly, unlikely.

WEB RESOURCES

MLB Team Records by Season, URL: http://sports.espn.go.com/mlbhist/alltime/season

Wikipedia Major Leage Baseball Season, URL: http://en.wikipedia.org/wiki/Major_League_Baseball_season

Dan Schlossberg, "MLB Expansion", URL: http://baseballguru.com/dschlossberg/analysisdschlossberg10.html

Wikipedia Major League Baseball, URL: http://en.wikipedia.org/wiki/Major_League_Baseball

Baseball History, URL: http://www.mlb-players.com/history.php

Allen Barra, "Let Steroid Use be One for the Record Books," URL:http://www.opinionjournal.com/la/?id=110004791