upper deck

NOUN
10 LETTERS · STARTS WITH U

upper deck is a valid 10-letter word worth 20 points in Scrabble and 24 points in Words with Friends.

SCRABBLE WORDS WITH FRIENDS
U1P3P3E1R1D2E1C3K5
1 + 3 + 3 + 1 + 1 + 0 + 2 + 1 + 3 + 5 =20 PTS
DOUBLE WORD → 40TRIPLE WORD → 60
MEANING

What does upper deck mean?