If home-run frequency last year was not that far below some years of the Home-Run era, why are players no longer hitting 60-70+ home-runs per year?
To make a direct comparison, in 1998 the league hit 1.04 home-runs per team per game, and McGwire led the league with 70 home-runs. In 2009, the league hit 1.04 home-runs per game and Pujols led the league with 47 home runs. In 1998, 5 players hit 49+ home-runs. In 2009, O (zero) players hit 49+ home-runs. But the league overall hit basically the same number of home-runs in BOTH years.
Here’s another example: the league hit 1.12 home-runs per team per game in both 2001 and 2004. In 2001, Bonds led the league with 73 home-runs but by 2004 Adrian Beltre led the league with 48 home runs.
Since Bonds hit 73 in 2001, only three players hit more than 50 home-runs in a season, and none more than 54 homers.
What does it mean? And why does the passage of time show home-run frequency remaining well above the historic average, while individual players no longer post monster home-run seasons?
Here’s my hypotheses: Pitchers are, right now, just better – top to bottom – than they were 10-15 years ago, and batters are as good as they have ever been.
The argument would go like this: 1993 and 1998 saw the expansion of MLB to 2 and then 4 new cities. This meant by 1998, 4 new MLB rosters had to be filled, requiring that teams reach into the minor leagues and promote players who would otherwise not have qualified for a major league roster pre-1993/98.
The quality of pitching, especially, would have been diluted.
There would have been more pitchers who would give up a lot of home-runs. These weaker pitchers would have been feasted-upon by truly talented power hitters like McGwire and Bonds. The best would post record numbers.
Over time, the worst pitchers would be squeezed out by truly superior competition as they worked their way up and aged in to their baseball primes. The batters would be possibly the best in the history of baseball, but they would now be facing pitchers of a similar pedigree.
Home-runs would continue to fly out of major league stadiums at a historically high frequency – because really strong batters occasionally hit balls thrown by really strong pitchers – but even the best batters would find there were fewer weak links in opposing rotations and bullpens against whom they could pad their home-run totals.
Strike-outs would probably go up, and on-base percentage would probably go down, as these top-flight pitchers went about their business of getting batters out.
The smallest mistake pitch would still be deposited in the outfield seats, at rates higher than at any time in baseball history except the very core of the Home-Run Era, but these pitchers would make fewer overall mistakes.
That’s the hypothesis, at least. (With a tip of the hat to Stephen Jay Gould and his “spread of excellence” hypothesis on the disappearance of .400 hitters.)