Question Ill.18 / KO book

[Letangs]

Hello Peeps !

I was just going through the book of Kevin Blackwood - Play Blackjack Like The Pros and KO BJ in the meantime.

And something seemed really strange to me, or well, unclear to say the least.

Page 69 Blackwood gives a list of the illustrious 18 with Hi-Lo indexes.

You have roughly the same Page 85 of KO BJ.

While I understand with KO system a RC of +4 (Pivot Point) roughly equals a TC of +4 in HI-LO, and Key Count roughly equals a TC of somewhere between 0 and 1 in HI-LO, something looks not right somewhere.

Taking for exemple 16v9

HI-LO index is +5
KO index is Pivot Point (+4)

That looks ok to me. KO system is devised to be simple and only use 2 index values for 6 decks games, PP and KC. +4 or +5 doesn’t make a big difference.

Next one, 16v10

HI-LO : +1
KO : Key Count (somewhere between 0 and +1)

This is ok again,

Here comes the problems... !

9v2
HI-LO is +1

Yet ...

KO says Pivot Point (+4)
That makes quite a BIG difference !!
It should be Key Count, but never pivot point !

Is it a mistake in KOBJ book ? To me it looks like a mistake ....

Also, KOBJ says something about 8v5 and 8v6

Yet Blackwood doesn’t speak about it, why that ?
Did the KO book just try to replace the «*not to use*» indexes of 10/10 vs 5 and 10/10 v 6 by the two most important indexes following up being 8v5 and 8v6 ?

If someone can enlighten me on this, it would be great.

Thanks !

[CountinCanadian]

Hello Peeps !

I was just going through the book of Kevin Blackwood - Play Blackjack Like The Pros and KO BJ in the meantime.

And something seemed really strange to me, or well, unclear to say the least.

Page 69 Blackwood gives a list of the illustrious 18 with Hi-Lo indexes.

You have roughly the same Page 85 of KO BJ.

While I understand with KO system a RC of +4 (Pivot Point) roughly equals a TC of +4 in HI-LO, and Key Count roughly equals a TC of somewhere between 0 and 1 in HI-LO, something looks not right somewhere.

Taking for exemple 16v9

HI-LO index is +5
KO index is Pivot Point (+4)

That looks ok to me. KO system is devised to be simple and only use 2 index values for 6 decks games, PP and KC. +4 or +5 doesn’t make a big difference.

Next one, 16v10

HI-LO : +1
KO : Key Count (somewhere between 0 and +1)

This is ok again,

Here comes the problems... !

9v2
HI-LO is +1

Yet ...

KO says Pivot Point (+4)
That makes quite a BIG difference !!
It should be Key Count, but never pivot point !

Is it a mistake in KOBJ book ? To me it looks like a mistake ....

Also, KOBJ says something about 8v5 and 8v6

Yet Blackwood doesn’t speak about it, why that ?
Did the KO book just try to replace the «*not to use*» indexes of 10/10 vs 5 and 10/10 v 6 by the two most important indexes following up being 8v5 and 8v6 ?

If someone can enlighten me on this, it would be great.

Thanks !

Maybe, due to the higher imprecision of an unbalanced count, while hit/stand decisions will seem to be equivalent, double down decisions have to be more conservative as you're taking greater risk, almost "risk averse" indexes per se, to prevent doubling too early

[lij45o6]

You are looking at two different systems here!

While, yes, it may seem that the I18 *can* be used, it is ill-advised due to the unbalanced nature of the count.

Best bet is to compute them with CV or use the data in KOBJ by K&O.

[Letangs]

I know it’s a different counting method tho I can’t explain the difference of the advantage for 9v2 ..

+4 is close to 2%
+1 is just 0.5%

Doesn’t make sense to me

[Three]

I know it’s a different counting method tho I can’t explain the difference of the advantage for 9v2 ..

+4 is close to 2%
+1 is just 0.5%

Doesn’t make sense to me

Compared to a balanced count, an unbalanced system you will hit the strike point at different TC equivalences and different frequencies. It is always better to err on the side of a lower frequency of errors. Griffin discusses this for balanced counts in his book. To paraphrase, always using an index one TC early can be worse than always playing BS or at least will cost most the the EV for the matchup deviation. If you err on the one TC past the index you are only giving up the minimal EV gain at the index. Think about how that might apply to unbalanced index values where the RC's TC will depend on depth and the frequency of each depth at the RC is not evenly distributed between depth, depth at any RC represents the TC.

Also the cards added to the count in order to create the imbalance can affect the play. The seven is added to give you the imbalance. The 7 has the highest EoR for 9v2.

[DSchles]

Hello Peeps !

I was just going through the book of Kevin Blackwood - Play Blackjack Like The Pros and KO BJ in the meantime.

And something seemed really strange to me, or well, unclear to say the least.

Page 69 Blackwood gives a list of the illustrious 18 with Hi-Lo indexes.

You have roughly the same Page 85 of KO BJ.

While I understand with KO system a RC of +4 (Pivot Point) roughly equals a TC of +4 in HI-LO, and Key Count roughly equals a TC of somewhere between 0 and 1 in HI-LO, something looks not right somewhere.

Taking for exemple 16v9

HI-LO index is +5
KO index is Pivot Point (+4)

That looks ok to me. KO system is devised to be simple and only use 2 index values for 6 decks games, PP and KC. +4 or +5 doesn’t make a big difference.

Next one, 16v10

HI-LO : +1
KO : Key Count (somewhere between 0 and +1)

This is ok again,

Here comes the problems... !

9v2
HI-LO is +1

Yet ...

KO says Pivot Point (+4)
That makes quite a BIG difference !!
It should be Key Count, but never pivot point !

Is it a mistake in KOBJ book ? To me it looks like a mistake ....

Also, KOBJ says something about 8v5 and 8v6

Yet Blackwood doesn’t speak about it, why that ?
Did the KO book just try to replace the «*not to use*» indexes of 10/10 vs 5 and 10/10 v 6 by the two most important indexes following up being 8v5 and 8v6 ?

If someone can enlighten me on this, it would be great.

Thanks !

Simplest explanation: the earlier values you gave were for hit/stand, which don't involve risk aversion. The 9 v. 2 index, for doubling, is subject to risk aversion. That value is higher than the e.v.-maximizing index, and it may be the r-a index that the K-O book was providing.

Don

[Letangs]

Thank you everyone, that definitely makes sense !

I get that the RC must be «*higher*» than hi-lo index because as in KO the 7 are counted +1, and 7 can give you one of the shittiest hand (9+7 vs 2) it’s better to ensure that more 7s are out. Definitely makes sense !

May I ask you what’s your opinion regarding the 2nd part of my OP ?

«*Also, KOBJ says something about 8v5 and 8v6

Yet Blackwood doesn’t speak about it, why that ?
Did the KO book just try to replace the «*not to use*» indexes of 10/10 vs 5 and 10/10 v 6 by the two most important indexes following up being 8v5 and 8v6 ?*»

Thanks !

[Three]

I get that the RC must be «*higher*» than hi-lo index because as in KO the 7 are counted +1, and 7 can give you one of the shittiest hand (9+7 vs 2) it’s better to ensure that more 7s are out. Definitely makes sense !

The 7 is the same as any other low card for you with 9v2 doubling index (all give you a stiff to hope the dealer busts), but it makes the dealer a 9 to add cards to. That is not good for you.

[Letangs]

The 7 is the same as any other low card for you with 9v2 doubling index (all give you a stiff to hope the dealer busts), but it makes the dealer a 9 to add cards to. That is not good for you.

Okay, I get it.
Definitely makes more sense now.