Thirteen cards can be divided into four groups to form just 39 different patterns, but of those patterns only 13 come up more than 1% of the time. Usually specifying a hand shape of, say, 4-4-3-2 or 4432 does not imply any order of the suits, but a shape of 4=4=3=2 specifies exactly four spades, four hearts, three diamonds and two clubs.
Here are the most common shapes grouped by the longest suit, and colour coded by category:
(48% of hands)
Since bridge players need to count up to thirteen a lot—the shape of each opponents' hand, and the division of the cards in each suit—learning these basic patterns by rote will give you precious time to think about other things in the hand.
You can practise your hand shapes below...