For years, I have been searching for the 'real meaning' of the phrase 'he has his dauber down...', seen in sportwriters columns about baseball and the America's cup race, and heard over the radio from baseball play-by-play announcers.

I can imagine that its meaning is something akin to 'lower lip stuck out', but so far, no dictionary I've found has such a meaning listed.

Just the other day, a friend used the phrase in a non-sports context, but with similar meaning. When I smiled and asked him exactly what he meant, he was at a loss for an exact meaning...

Help! From where does this phrase come?