Yeah, that's how I do it.

And I got absolutely smoked by the guy who skipped that step.

(Now I need to remember to time myself next time.)

I think I might try the "spread 52 and go" method. Higher variance I'll bet, but I like to gamboooooooooool.

Oh, btw, while getting a set-up the other night, I crossed the two decks to hand them off to the floor who had just dropped off the new set-up. When doing this, I always make sure the bottom card on these decks is not the A, for obv reasons (or maybe it's not that obv, because the floors routinely tell me that they've never seen anyone else do that).

Any way, this time, there was the A on the bottom of BOTH decks! What are the odds?

Which reminds me of an old sucker bet: give your mark a deck of cards, and ask him to shuffle it, while you shuffle a second deck of cards. Pick up your deck like you're going to deal, and ask him to do the same. Turn the top card face up on the table, and ask him to do the same. Let's say you turn up the 3 and he turns up the 7.

"What I'm trying to do is turn up the exact same card that you do," you explain. Let's try it again." You turn up the Q, he turns up the Q, and you each place them on your respective face-up piles.

"No, that's not a match, they have to be the same suit, too. I'll betcha I can do it before we reach the bottom of the deck."

Then hope he takes the bet, because you're a huge favorite here. If you don't believe me, grab two decks and run it a few times.

51! / 52! = 1/52 chance that you won't get a match.

He is a great guy. That is the same way I suit a deck.

The bolded tilted me. That should be routine/automatic. This actually goes back to hand shuffling; the deck can't go in the well with an ace of spades on the bottom so the dealer following will know if it is has been used.

I do the same except i also rank the suits in hand, cards never touch the table. Ill have to time myself, still don't think Im close to 40 seconds though but i can do it just about as quickly as the standard method that most use.

The setup talk reminded me of a story years ago on a riverboat.
Just had a "card-party", i recall it was at least 10 setups, the dealers were filtering away from the table, supervisor called surveillance to let them know they were taking the setups back to the lockup.
They picked up all 10 boxes took a few steps towards the cage, and stumbled.

"1040 card pick-up", the re-setup party took a lot longer.

THAT reminds me of the time i dropped a rack of backs chips when doing a fill. It was actually on the counter and by suit sleeve button caught it and pulled if off the counter)

Luckily i was inside the (small two window) cage in the poker room when i did it.
took me 4 hours to find all the chips, the bounded and rolled beside and behind the most unlikely places.

Personally I've always thought staff should have to wear short sleeves. Makes it harder to slip cards or chips up your sleeve when the sleeve begins above your elbow. Woulda prevented the Bellagio poker dealer from using his custom hardware doohickey to pilfer $1000 chips from the big games. And as a side effect, it's just more convenient to have no sleeves to get in the way.

I don't disagree, As a dealer i prefer short sleeves for ease of motion. I was wearing a suit then as required by company policy because i was running the shift and the poker cage, i would have preferred short sleeves then as well.

Sahara used to let the poker room supervisor go suitless. None of them ever put on a tie. They'd just wear nice pants and a nice shirt and that was that. Worked just fine. I never noticed any breakdown in order within Sahara caused by a supervisor not wearing a suit. 'Course, Sahara closed. Maybe this is why.

I used to be a big believer in suits. I often wore a suit when on the floor when it wasn't required. I am 40 with years odd experience, so I don't need a suit; when I was in my 20s and needed to maintain order with older school players, it helped convey the message that I was serious business.

Well there is a happy medium where you can dress less formal than a suit and still dress with an air authority.

Actually, I think it's 51/52 each time, or 51/52 to the 52nd power = about 36% not to happen at least once as you go through the decks.
(Each event is 51/52, since the card you need may already have come out; e.g., when you get down to the ends of the decks, last attempted match is still 51/52 not to match, not 1 out of 2).

This is correct.

They're not independent events.

Hmm. I'm not sure. There are known cards, but they're not always helpful, so... I'm not sure what it ends up being, honestly. You could be right.

I think that's close, but not exact. A good approximation at least since you can probably get a payoff of 1:1 for that and if you're 64/36 or 65/35 or 66/34 it doesn't really matter all that much.

Heck, just to see let's do it with three cards. I'll assume that the cards on one deck come out as 1, 2, 3 (rename them so they do, it doesn't matter).

Then the other deck can come out one of six ways:

123 match
132 match
213 match
231 no match
312 no match
321 match

So that's 4/6 winners for us or 66.66%. The 1 - (2/3)^3 method gives 70.37%. I think as the deck gets larger the numbers (actual and the approximate method's results) will get closer to each other.

The answer is !52 / 52! = 36.78% for no match.

does the following part of this matter
So by the time he makes the bet here both decks are reduced to 50 cards and each deck contains 2 cards that have no match in the remaining deck.......

It doesn't make a significant difference.

Since we're talking suits, another sportsbook story:

The backroom at the IP sportsbook, where the supervisors spent most of their day, was TINY. If four of us were back there, it felt a little crowded. Five was definitely crowded, and six was standing-room-only. In this tiny, tiny room, we had three computers, three old giant-tube computer monitors, five 19" tvs, and close to a dozen 9" tvs. All this equipment put out a lot of heat, trapped in this tiny room, filled with grown men.

They let us wear polo shirts. I told them more than once that as much as I loved my job, I'd have to quit if they made us wear suits in that environment.

I'm a computer guy. When the stats get fuzzy, I start simulating, and this isn't a hard simulation to write. Dunno if I got the code right, but my simulated results match this pretty closely. After 100K deals it matched 63245 times. 63.25% matched, 36.76% no match.

And WTF is the prefix exclamation?

edit: I looked it up, the prefix ! means subfactorial. This problem is derangements divided by permutations. Factorials are the number of possible permutations of a sequence, and subfactorials are derangements: the number of possible permutations in which no single item in the sequence is in its original ordinal spot. This simulates decks without matching card pairs in the entire run.

Its right even if you use a deck stripped down to a dozen cards. It converges to 1/e and gets really close once the deck size gets about that big. So if you want to "see for yourself" you can do it accurately with stripped decks.

I don't know how to modify the formula to re-calculate the odds after n cards have been flipped out of the 52 and still no match exists. Would be interesting to know.