Consider the following ...
• There have been 14 unassisted triple plays in baseball's history.
• Six of them happened between 1920 and 1927.
• There were no triple plays between 1876-1909 and 1927-1968.
• Ron Hansen (who was coincidentally at Monday's game, working as a scout) turned an UA triple play for the Washington Senators in 1968, but another drought of 24 years followed.
• Since 1992, six unassisted triple play have occurred, starting wth Mickey Morandini in '92 and going through John Valentin ('94), Randy Velarde ('00), Rafael Furcal ('03), Troy Tulowitzki ('07) before ending with Cabrera's in '08. In 16 years, the total of UA triple plays almost doubled itself.
Nick has a number of theories for the increase, ranging from line-drive percentages to more teams equaling more innings and opportunities to the fact that the two triple-play packed periods also coincided with the "Lively Ball Era" (1920s) and the "Juiced Ball Era" (1990-???)
In all likelihood, it's probably a combination of all of the above and even more.
Anyone else out there have other theories for the explosion?
UPDATE: This is interesting and I really have no idea what it means (if anything), but I just noticed that since 1968, teams that turn the unassisted triple play are 2-5.