Given the historic and unprecedented rise in strikeout frequency in Major League Baseball, On-Base Percentage is diminishing. During the Home Run Era, league average OBP never went below .330. In 2010, it went down to .325 and slipped below the .320 threshold last year (2012 – .319). This year, league average OBP is down to .317.
Some of this decline in league average OBP is connected to a reduction in the number of walks. Again it appears that pitchers are doing a generally better job – they are walking fewer batters and striking out more batters than ever.
Major League Baseball started tracking Intentional Bases on Balls (IBB) in 1955, and 2013 is shaping up to be the year with the lowest frequency of IBB per team per game (.20). The next lowest year is a tie – 2012 and 1998 at .22.
Someone who wants to reduce everything to home-runs would say that intentional walks are going down because pitchers are no longer afraid of batters who are not on steroids, and thus less of a threat to hit a home-run. But that ignores a couple simple facts.
First, IBB were never that common during the Home Run Era. Only twice (1996 and 2002) did seasons in the Home Run Era see an IBB rate reach .30. In 2001, when everyone was intentionally walking Barry Bonds, the IBB rate per team per game was .28.
Second, home-runs never really went away. They are far more frequent now than any time before the Home Run Era, and not that much lower than they were during several years of the Home Run Era. But intentional walks continue to disappear.
There was an era when IBB were common. The 10 seasons with the highest frequencies of IBB were all recorded between 1965 and 1975 (ranging between .34 – .40 IBB per teams per game). During this time, the frequency of home-runs was about average for the post-war history of baseball, fluctuating between .61 – .88 home-runs per team per game.
There just doesn’t appear to be much correlation between the frequency of home-runs and IBB.