I18 thresholds

I know this may seem silly, but am I correct in assuming that the indices in the I18 are thresholds? For example, #2 says hit a 12 v. 4 when TC = 0. I also assume that this index is in play with any negative count, i.e., anything <0.

And as a side note, does anyone know why Schlesinger ordered them the way he did? Does it has something to do with how much difference it makes in the EV? For learning them, I've reordered them according to the count. So now when I'm practicing at home and the TC reaches, say, +2, I think to myself, "What indices are now in play?" My rationale is that I'm much more likely encounter to play with a TC of -1 or +1 count than +3 (take insurance, #1 on the list) or +5 (split 10s v. 5, #4 on the list).

Quote: theoriemeister

I know this may seem silly, but am I correct in assuming that the indices in the I18 are thresholds? For example, #2 says hit a 12 v. 4 when TC = 0. I also assume that this index is in play with any negative count, i.e., anything <0...

It is easier for me to think in terms of standing rather than hitting. So, TC=0 is the threshold for standing with 12 v. 4. Stand on 12 v. 4 when the TC is greater or equal to 0, and hit otherwise.

Thanks, Chester. Yeah, I probably should have phrased it in terms of basic strategy, "stand unless the TC <0."

Quote: theoriemeister

I know this may seem silly, but am I correct in assuming that the indices in the I18 are thresholds? For example, #2 says hit a 12 v. 4 when TC = 0. I also assume that this index is in play with any negative count, i.e., anything <0.

And as a side note, does anyone know why Schlesinger ordered them the way he did? Does it has something to do with how much difference it makes in the EV? For learning them, I've reordered them according to the count. So now when I'm practicing at home and the TC reaches, say, +2, I think to myself, "What indices are now in play?" My rationale is that I'm much more likely encounter to play with a TC of -1 or +1 count than +3 (take insurance, #1 on the list) or +5 (split 10s v. 5, #4 on the list).

You are correct. They are the thresholds for when to change strategy. Think of the ways to make a 12... 10-2, 9-3, 8-4, 7-5, 6-6... All of these ways are even or positive. Then with the dealers up card of a 4, this will always be positive, which is why you won't ever use this index on the first hand. If the first hand of a shoe is 12v4, then you are at worst a RC +1, which means the TC is 'slightly' above 0. The only time the TC is 0 is when the RC is 0. For this index (12v4), I essentially sum it up in my brain as "Whenever the RC is negative, the TC is to 'some' extent negative, thus 12 should hit to a 4 since 0 is the threshold." Hit your 12v4 in any negative count.

I'm not sure why Schlesinger ordered them the way he did, but most of the time when you see the I18 they are not in order by the count because yes they are in order of most valuable to least (why insurance is at the top, because that is most of your EV from deviations). I just checked on the Wizard's Hi/Low Intro Page and yes, even he says they're in order of value: "The lists are given in order of value."

Quote: theoriemeister

Thanks, Chester. Yeah, I probably should have phrased it in terms of basic strategy, "stand unless the TC <0."

A picture is worth a thousand words. Tom squeezes in the i18 onto the BS chart. Tom's chart makes it easier to understand, then learn and memorize the i18.

Thanks, Artemis.

Quote: Artemis

A picture is worth a thousand words. Tom squeezes in the i18 onto the BS chart. Tom's chart makes it easier to understand, then learn and memorize the i18...

There are also encoded, and unencoded basic strategy cards for sale on BlackjackInfo.com that has the I18 on the basic strategy card boxes as well.

Since 55 is never split wouldn't the same indices (i.e. hit vs. double) that apply to other hands of 10 apply there as well?

Quote: Kellynbnf

Since 55 is never split wouldn't the same indices (i.e. hit vs. double) that apply to other hands of 10 apply there as well?

No. @ true count of >=5 against a dealer's 5 or 6 (see Tom's chart below), an AP splits 10s because he's likely to receive more monkeys, and he'll likely to make 2 hands of 20s. On the other hand, if he splits 5s, he'll likely to receive 2 hands of 15s. It's all in the math, i.e., No SPLITTING of 5s at all per the computer simulation of 1,000,000,000 of blackjack hands:-)




Edit: Opps...Wizard has already answered your question...

Quote: Wizard

[on October 22nd, 2011 at 4:59:40 PM] See my blackjack appendix 9.

What I meant is that you'd use the same indices that you'd use for regular hands totaling 10 for a pair of fives as well, not that you'd ever split them.