The reference manual indicates that decks have a Map-level property called <name>_numCards. After many frustrating failed attempts at getting this to work, I checked out the source code and discovered that the property is actually called <name>_numPieces. (Seems like a better name anyhow, because decks are not restricted to holding cards)
Just thought I'd post a note for anyone else searching for the answer. (I'm sure the docs will get updated in the future ;) ) Cheers -Tim
