A couple of days ago I was playing my nine trillionth game of Solitaire when I noticed that there's something odd about the eight of diamonds. For each rank of cards the pips match each other across suits, For example with the sixes there are two columns of three pips and this is the same for all four suits. The single exception is the eight of diamonds where the pip pattern doesn't match the other three suits. I asked a friend and he confirmed my startling discovery on his computer. So now I'm wondering whether this is unique to Microsoft Solitaire or if this is the common layour for playing cards.