Why does it always rain on me?

Well this post should have been titled Game 31 at Fenway, but a combination of poor-health, and the change in game time meant that I stayed home and watched on NESN. And having watched the game, I have to say that I am not too disappointed - it would have been nice to see Wade Miller's pitching debut - 5 nice innings, with a truly knee buckling curve ball thrown for strikes... it would have been nice to see Cla Meredith's pitching debut (called up after only one game at AAA, and having become only the second player from the 2004 draft to the majors) - well it would have been nice if Francona hadn't called on him at a strange time to make his debut, but at least Meredith made his debut "memorable"... it would have been nice to see David Ortiz appear to get back on track with several big hits... but it really would have been very, very wet!

Are there any hard and fast rules on when a game gets called for rain?

When the players are wiping the bill of their batting helmets between pitches.... is that not a sign?

When the grounds crew have to work on the mound between batters... is that not a sign?

When small children appear to be drowning in the stands... is that not a sign?

And of course what it all boils down to, is that the Sox lost the second half of a day / night doubleheader - which seems kind of inevitable...

In trying to find some sort of statistical evidence to support that view (that most doubleheaders result in a split) I was looking through a lot of the information at Retrosheet, and while not finding a doubleheader database, in the same vein (that is, evidence v memory), I did enjoy David W Smith's article, debunking many of the classic memory over matter stories from 'yore'. If anyone can point me in the direction of a doubleheader database, use the comments!