Gadarene:
I’d heard that Soupy Sales caused a bit of an uproar when he made that joke. 
No, it still makes sense. Assume that pre-expansion, all players in the league are rated A to C, on some absolute scale. To add 50 players to the league for an expansion, you’re not going to find a trove of previously undiscovered A-C talent; you’re going to add “D” quality players. You would still have “C” hitters struggling against “A” pitchers, but you now have A-pitchers facing D-hitters, and A-hitters facing D-pitchers. The result of the latter face-off would be that an “A” hitter gets a boost in his individual stats–say, a new home run record. Which is exactly what happened in 1961.
As for the corollay: sure, A pitchers can get fat off D hitters. Maybe this explains Randy Johnson and Pedro Martinez.
Perhaps steroids could have something to do with it. These accusations of rampant steroid use (50-85%) coupled with the obvious advances in strength training offer an explanation that doesn’t require dilution of pitching, juiced ball, or corked bats. Stronger players = higher bat speed = longer drives = lots of home runs.
Considering that there are no rules governing steroid use in Baseball, it would not surprise me at all.
BUT, as was pointed out by Jorel above, the pool of players has dramatically increased. In addition to the growth in population in the United States, and the end of segregation in baseball, teams are identifying, signing, and bringing to the United States talent from all over the world. Expansion of the number of major league jobs has not occurred at a pace faster than expansion of the pool of people from which major league baseball players are drawn.
However, the home run rates for all PRE-expansion pitchers, as a group, has gone up. That cannot be explained by expansion; there is obviously a change in the conditions of the game.
And it’s easy to see what those changes are; players are much stronger - which may have something to do with steroids but is largely just a new acceptance of stength training, the umpire’s handling of the strike zone and batter’s box has swung in the hitter’s favour, and a number of homer-friendly ballparks have been built. There isn’t a lot of mystery here.
As Squooshed points out, expansion has been more than offset byu the expansion of the population, improvement and scope of scouting, and talent from other countries. The influx of Asian talent is already starting to have a significant impact on the quality of play in the major leagues, and the last 20 years has also seen a number of Australians making the big leagues. Caribbean players fill the majors. There’s no shortage of talent.
Were you disgusted when he had only hit 3 HR’s up to that point in the season?
And can you name me 1 150 lb shortstop???
Not to beat a dead horse…but…
I agree that there are numerous factors, including expansion, weight training, influx of foreign players/expanded talent pool, smaller parks, and steroids.
But I think it should be pointed out that the influx of Caribbean and Latin American players took place in the '50s and '60s–I think that wave has crested. And the “influx” of Asian talent can be counted on both hands–for position players, 1 hand.
I couldn’t find any 150 lb shortstops but I found around 11 infielders (too lazy to find out the position I guess) in the 159-166 lb range.
I’m just saying…
A 4 homer game is hardly the sacred domain of baseball’s greats. I mean, Mark Whiten did it.
I cannot say I am thrilled by the turn my sport has made made over the last ten years, including the fact that all of these “bigger, more powerful players” started first jacking 50, 60, 70+ homers regulary around the time of the '94 strike, when some of them had been in the game prior to then, and had not been able to do so. But, when looking at Green’s 4 HR night, keep in mind one thing: As much as I love 'em, the Brewers are a truly awful team, and they served up meatballs all night. I think the Brewer’s pitching, and not a juiced ball, is why Shawn got his 4 that day.
This has all been a nice interesting discussion, but I think the OP is based on fallacious logic–one statistical blip does not indicate a trend. The fact that 2 4-HR games occurred in the same season is not statistically meaningful.
Look at other blips in the past: Johnny Vandermeer pitched no-hitters in consecutive starts. The Giants and Cardinals threw no-hitters at each other on consecutive dates. Nobody got overly worked up about it.
JSC is right about the four HR game-for now. The telling stat that shows a trend in more multi-home run games is the three home run game:
http://sportsillustrated.cnn.com/statitudes/news/2001/04/05/three_homers/
This article is a bit old, and it doesn’t break the trend down as well as an article I read last week at either espn.com or sportingnews.com (sorry, I couldn’t find that article back), but it still shows that multi hr games have shot upward in the last ten years. That trend does support the statement in the OP.
Many of you have made valid posts. And I think there is more to it than a juiced ball. After reading the SI article, it seems the ball isn’t the only thing that’s juiced out there.
jsc makes an interesting point about statistics. Perhaps the anomoly of 2-4 home run games in a season isn’t nothing to get riled about.
And perhaps the phrase “integrity of baseball” is an oxymoron. Things do change, but not necessarily for the better. I don’t know the stats, but I’d be curious about the number of homers hit on average before the strike and how many homers were hit after. If owners want more homers (because home runs sell tickets), why not let each player cork their bat, take roids, use whatever means necessary to pop them over the fence. And remember… Roger Maris hit his 61 before the mound was lowered. That’s more impressive than the 73 hit by Bonds (who before this explosion, never hit 50. Yeah, I’m buying his story of offseason workouts.)
I think in a lot of ways, I just don’t relate to the sport any more, and it disappoints me. I can still name the players on the Big Red Machine and the great Oakland teams of the 70’s… Now, I can’t even name the starting 8 for my own team.
But something’s in the water. The last 150 lb shortstop I can remember is Mario Mendoza. (I’ll bet he could pop 15 homers today) OOOH! Don’t forget the forgettable Vic Davalillo