The evolution of the lefty specialist

In 1962, something happened in MLB that had never happened before:  a pitcher appeared in at least 40 games, and finished the season with fewer innings pitched than games.  It was the Reds's Bill Henry, and he appeared in exactly 40 games, with only 37.1 IP.  To no one's surprise, he was a left handed pitcher.

The next season, the Los Angeles Angels's lefty Jack Spring duplicated Henry's feat, appearing in 45 games with just 38.1 IP.  And in 1967, the Astros's lefty Dan Schneider became the third player to accomplish this feat, bettering both Henry and Spring by appearing in 54 games for 52.2 IP.  Schneider would only appear in 6 more games in his career.  Lefty Al Jackson would do it too in 1969, playing for both the Mets and the Reds. He never pitched again.

In the 70s, three pitchers would join the club:  the Astros's Jack DiLauro in 1970, the Phillies's Eddie Watt in 1974, and the Rangers's Joe Hoerner in 1973 and 1976.  Only Watt was a righty.

Here is a breakdown in # of pitchers per year that did this, since 1980:
1980: 1
1981: 1 (strike season)
1982: 1
1983: 2
1984: 2
1985: 1
1986: 3
1987: 3
1988: 3
1989: 2
1990: 4
1991: 8
1992: 25!

Of these first 62 players to appear in 40 games with fewer IP than games, only 10 were righties.  Since 1992, the numbers have climbed steadily.  In 2012, 114 pitchers appeared in 40 games with fewer IP than games, but 76 of these pitchers were now righties!  What used to be almost exclusive to lefties is now dominated by righties.  The game changed a lot in the early 90s, that's for sure.  It's just hard to believe it happened so fast.

Here is the list of pitchers per year, since 1992:

Year ▴	#Matching
1992	25
1993	30
1994	20
1995	31
1996	31
1997	34
1998	40
1999	39
2000	42
2001	60
2002	49
2003	59
2004	58
2005	67
2006	66
2007	85
2008	85
2009	93
2010	100
2011	106
2012	114

Provided by Baseball-Reference.com: View Play Index Tool Used
Generated 6/6/2013.