Knock-Out Key Count

[stunshots]

How is the key count calculated?

Based on the description of the key count on page 47, the table on page 75 doesn't make sense to me. Where the numbers came from isn't explained.

In 1 deck there are 4 more low cards than high cards. With a IRC of -4, the RC would need to be 0 to have an equal number of low and high cards. It would seem that the key count would then be +1. That's when we have an advantage with more high cards in the deck.

Am I missing something?

 

[zengrifter]

I need someone to answer this who is conversant with KO. I don't have a copy handy! zg

Ps - While we wait for the answer, if you look in theforums carefully you will find several viable methods for further streamling KO without loss of EV.

 

[Canceler]

Disclaimer: I don't have the book either, and I don't know how the key counts were derived.

What I do know is that an IRC of -4 implies double deck, and the key count is +1.

 

[Mikeaber]

Hmmm....I believe the page you make reference to is talking about an example of "counting" an equal number of black and white balls. In Blackjack application, there is not an equal number. IRC for Single deck is +0 and the Key Count is +2. When the count is SD is +2, you first have a slight advantage. Move on to page 75 for further discussion on the way the count is explained in more detail when used with a deck of cards.

 

[stunshots]

Ooops! Im my original post, I mixed values from single deck and two deck backs. Sorry.

To restate it correctly for single deck. Using the concept of the gumball analogy, there are four more low cards than high cards in a single deck. With an initial count of 0, the count would have to be +4 to be at the pivot point and + 5 to have the advantage with more high cards in the deck.

Later in the book, it is mentioned that penetration effects the key count. I don't have the book in front of me, so I can't state the page. It's one that is referenced in the index. I don't understand why in does have an effect.

The pivot point and key count values stated are consistent everywhere I've seen them used (book and web), so I trust that they are the correct values and use them. Obviously, the actual pivot point and key count are calculated with more complicated criteria not mentioned in the book.

I'm just courious as to what the factors are that effect the key count and why.

 

[Gregory]

What's most telling is the graph on page 98 which shows your expectation as a function of the running count. Based on simulations, anything below a running count of +2 with a single deck has a negative expectation for you.

 

[stunshots]

Let me ask another way. How do I calculate expectation (%) for a given key count as plotted in figure 6 on page 98?

 

[zengrifter]

Let me ask another way. How do I calculate expectation (%) for a given key count as plotted in figure 6 on page 98?

I think you mean RC. Your expectation is always the same for KC regardless of where you are in the deck... more or less. zg

 

[stunshots]

Yes, I should have written RC.

It now appears to me that the key counts were established emperically through simulation of expectation using various factors such as RC and penetration.

The statement that penetration effects the key count that I mentioned earlier is on page 166.

Although I didn't get a direct answer to my questions, your responses were helpful. Thanks.