eBay Wins #63

I've been hunting for penny cards again, and this time I came up with 6 1989 Donruss commons.

1989 Donruss
#296 Walt Terrell
#302 Mike Brumley
#308 Ron Robinson
#314 John Shelby
#320 John Farrell
#325 Kevin Bass

I wasn't sure I could even get out a full sentence about these 6 cards. None of them were ever Cardinals, and everyone's in pretty standard late-80s uniforms, except maybe Mike Brumley up there in a brown Padres (presumably batting practice) jersey. Then I noticed that, by simply lining up these 6 non-consecutively numbered cards in order, the left-to-right gradient colors matched up perfectly. If I hadn't already sleeved and filed these away, I would have re-scanned in one long strip, because the Robinson and Shelby would even match up.

I wonder what the odds are of that happening.

When I start wondering about numbers, I can't help myself; I have to try to calculate the answer. To make it straighforward, assume 6 random different cards, and put them in a fixed order. There are 660 cards in 1989 Donruss, and 5 color patterns - Red-Yellow, Yellow-Green, Green-Blue, Blue-Purple, Purple-Red. Assume that exactly 1/5 of cards - or 132 - have each pattern. The color of the first card won't matter. The next card has a 132/659 chance of matching the border. It would be 132 in 660, or 1 in 5, but the first card has been removed from the pool. Assuming that works, the next card has a 132/658 chance of aligning, the fourth card's is 132/657, the fifth's is 132/656, and the sixth should match the first card, so there are 131 of 655 remaining cards that can finish it off.

By my count, that's just a 0.03% chance of this lineup happening. That's enough to make me want to go play the state lottery tonight.

Of course, these cards aren't randomized, they're sorted by number, and Donruss doesn't seem to follow a pattern of colors, so I'd have to enter all of the cards into a table by color and check each possible collection of 6 cards for the gradient match to get the true odds for this set. I'll stick that on my to-do list, somewhere after re-staining my deck, but before solving the world's energy crisis.

eBay Bargain Tracker
Total Cards Bought	2115
Total Spent	$40.02
Per Card	1.892 cents