Questions about Burn Cards

[emk211]

Okay, I was just watching a game on youtube and a question popped into my head about the way cards are dealt in real games versus online and I wonder if someone knows the answer...

When they deal at a real table they always burn cards before they turn and this changes the odds because the card is turned down without anyone seeing it, then they flop and before the turn, they burn another card, then on the river they burn another card, essentially removing 3 cards from the deck that affected the outcome of the hand being played....First why do they burn cards? It becomes a 49 card deck instead of 52.

Online they never show you if they are burning a card and my ultimate question is...Do the computer algorithms allow for the burning of 3 cards for any games or all games or no games? This 3 card difference changes things doesn't it? Or am I just crazy for thinking it does?

Inquiring Minds

 

[neart13]

It doesn't change the odds! The reason they burn cars is basically superstition turned into tradition! They thought by burning a card it would be harder for someone to rig the deck! So if they could put five cards in a row and they'd have to be able to rig it to include the burnt cards!
It doesn't effect the odds or change the size of the deck because the odds calculations are based on what's on the table and in your hands ie the known cards! Yes it could have burnt a card you need but also an opponent may have folded a card you need! So it's the same thing!
If we played a game with a 52 card deck but you threw away 20 cards at random and then we played with the remaining 32 cards, I'd still have to do calculations based on 52 cards unless we both knew what the 32 cards were, then we'd know what wouldn't come up!
I forget which one (possibly 888) but I remember one poker site did say that they do burn cards and another one said that they deal to the players then burn 3 in a row then deal the flop! I forget which online rooms these were!

 

[vinnie]

Burning is not done for superstition or tradition! Burn cards have a very specific anti-cheating purpose, a similar purpose to a cut-card when playing live. The burn card helps conceal information if the deck is not perfect or cards are marked. As a side benefit, the burn card and the cut card both make it more difficult for a crooked dealer to manipulate the deck while physically dealing the cards.

If a card is marked in such a way that a player can tell what it is, that could totally change the game. Say you have a pair of 6s and miss the flop. But, one of the sixes in the deck has a smudge on the back of it. You see that the card on top of the stub has that smudge. Now, if they aren't burning cards, you will always play for any size bet because you know you're going to hit your set on the turn. If they're burning cards, you'll probably fold because you know one of your sixes will never show up. In both cases, you know where a card is. But, knowing a card is out of play is less useful than knowing it will definitely be in play.

This information is more or less valuable depending on the game. In a shared card game, like hold'em, it is extremely powerful if you know the turn or river card before anyone else. But, even in stud and draw knowing that an opponent will get a card is valuable.

The purpose of burning a card is to conceal the value of the turn card from players who noticed deck irregularities or marked a card. There's no need to burn a card online to conceal that information, so a card room doesn't need to burn any cards. They can, and may, just because that's how the game is dealt. But, they don't need to. I have read that pokerstars does not use burn cards. Other rooms, I haven't seen specific information from them.

It does not change the odds. This can be proven mathematically. Say you have 4d-4h and the flop is Ah-Jc-7d. You know where 5 cards are, and there are 47 unknown cards. Your odds of hitting a 4 on the turn is is, 2/47 or ~= 4.3% (92/2196 using the same denominator as below). Now, if they burn a card, 2/47 times it will be a 4. And 45/47 times it will be a non-4. So, you can combine these probabilities, you will see that you end up with the same odds.

(2/47 * 1/46) + (45/47 * 2/46) => (2/2196) + (90/2196) => 92/2196 or ~= 4.3%

Burning cards does not change the odds. Odds are based only on the number of cards we know and the number of cards we don't know.

 

[perrypip]

It doesn't change the odds because you don't see them just like you don't see everyone's hole cards, which have also already be removed from the deck. When the turn card is dealt there are 47 cards you haven't seen in either case.

It's used in live games because the cards may be flawed or marked and someone may be able to recognize what it is. By burning it they will still know an ace is removed from the deck but that's much better than them knowing and ace is the next card coming.

It would serve no purpose online.

 

[rigor mortis]

Basically burning cards it to stop any possibility of cheating by card marking or the dealer manipulating the deck. The odds are unaffected by burning these three cards because you still don't know the other 50 cards from your pocket pair.

 

[Phoenix Wright]

Yes, as many have noted: burn cards have the effect of making it harder to potentially cheat and doesn't change the odds at all.

Of course, that doesn't mean someone talented with handling cards still won't find ways to cheat, but this is another debate

 

[scubed]

Nice thread! I had never considered why we have burn cards! Thanks for teaching me!

 

[vittopio]

I think this is done offline to combat fraud. And online, we must trust the integrity of the NHS.

 

[theRaven68]

Burning cards is anticheating activity and I think that result may be affected, in parallel we dont know anything about burning cards in online games

 

[Theiman2000]

The theory ive heard most is it came around with the wild wild west mostly when people were cheating like crazy