# Thread: Spanish 21 8-8 vs Ace Index Clarification

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## Spanish 21 8-8 vs Ace Index Clarification

In the Late Katarina Walker's book her index for 6deck H17 has
Against an Ace
8-8H/P: -2
And
Surrender:
8-8 -4

This doesn't make sense to me. Does this mean?

Hit -4>TC
Surrender -4<TC<-2
Split -2<TC.

Then to add to this confusion I will transcribe a paragraph (page 82), "Surrendering 8-8 versus Ace is a special case, when playing North American H17 and Pontoon. The NA H17 Index for surrender is -4, but when the true count reaches zero or above, splitting has a higher EV than surrendering, so we split. For Pontoon, the EV for surrendering decreases for the count, which causes a peculiar anomaly - although the surrender index is +2, we also surrender at TC=0."

New to AP.

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Originally Posted by JaviEngineer
Hit -4>TC
Surrender -4<TC<-2
Split -2<TC.
Not quite. The surrender index takes precedence over splitting. So if you can surrender at -2 and -1, then you do so, otherwise you split.
Originally Posted by JaviEngineer
Then to add to this confusion I will transcribe a paragraph (page 82), "Surrendering 8-8 versus Ace is a special case, when playing North American H17 and Pontoon. The NA H17 Index for surrender is -4, but when the true count reaches zero or above, splitting has a higher EV than surrendering, so we split.
At TC >= 0, this exception kicks in and you split.

There exists a similar situation for 17 vs A in 6D S17 LS blackjack using Hi-Lo where surrendering is correct across a range of true counts and the index for standing vs hitting falls within that range. I'm sure that Don and I are not the only ones to know this, but FWIW, detailed information will be released as part of our upcoming book on index play.

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Originally Posted by Gronbog
There exists a similar situation for 17 vs A in 6D S17 LS blackjack using Hi-Lo where surrendering is correct across a range of true counts and the index for standing vs hitting falls within that range. I'm sure that Don and I are not the only ones to know this, but FWIW, detailed information will be released as part of our upcoming book on index play.
Yes, that's correct! According to my CA, 4.5/6 pen I got the following:

Code:
```+------------+-----------------------+-----------------------+-----------------------+-----------------------+-----------------------+---+---+---+
|     TC     |      Probability      |        Standing       |        Hitting        |        Doubling       |        Insurance      | 1 | 2 | I |
+------------+-----------------------+-----------------------+-----------------------+-----------------------+-----------------------+---+---+---+
|          6 |   0.00780229775119936 |  -0.44324496600361474 |  -0.60667653225992479 |  -1.21335306451984959 |   0.07267761393993744 |   | S | I |
|          5 |   0.01062479094491303 |  -0.44812967552901944 |  -0.60013564249724149 |  -1.20027128499448299 |   0.05162259583762941 |   | S | I |
|          4 |   0.02352372474584670 |  -0.45337819034851601 |  -0.59291248605989666 |  -1.18582497211979332 |   0.02836567679086452 |   | S | I |
|          3 |   0.03324884909174893 |  -0.45855483566400823 |  -0.58588577792804275 |  -1.17177155585608550 |   0.00630936502963211 |   | S | I |
|          2 |   0.07049369173944747 |  -0.46386539184885150 |  -0.57852986491087433 |  -1.15705972982174865 |  -0.01669573180894030 |   | S |   |
|          1 |   0.10617007858083666 |  -0.46916944668791416 |  -0.57117221580351807 |  -1.14234443160703614 |  -0.03912267126929034 |   | S |   |
|          0 |   0.22514296072755205 |  -0.47449833083602072 |  -0.56365650447955562 |  -1.12731300895911124 |  -0.06189470271166969 |   | S |   |
|         -1 |   0.22293038916024879 |  -0.47939266993086088 |  -0.55705987357837849 |  -1.11411974715675699 |  -0.08260311602375962 |   | S |   |
|         -2 |   0.13759626345022322 |  -0.48491786195702674 |  -0.55019530948334083 |  -1.10039061896668167 |  -0.10620545853104899 |   | S |   |
|         -3 |   0.06357766031755364 |  -0.49062899866763587 |  -0.54297203570101538 |  -1.08594407140203075 |  -0.13032880551124487 |   | S |   |
|         -4 |   0.04297091153120088 |  -0.49591616050386922 |  -0.53614089215577110 |  -1.07228178431154220 |  -0.15295433796393768 |   | S |   |
|         -5 |   0.01945282425639147 |  -0.50160076459982961 |  -0.52876809178539863 |  -1.05753618357079726 |  -0.17670866656315418 | R | S |   |
|         -6 |   0.01392365468072426 |  -0.50654943660725005 |  -0.52219222065693760 |  -1.04438444131387520 |  -0.19778721782198558 | R | S |   |
|         -7 |   0.00592658233823324 |  -0.51223376871642601 |  -0.51468269322669535 |  -1.02936538645339071 |  -0.22124379925506166 | R | S |   |
|         -8 |   0.00442728480850521 |  -0.51670349850965880 |  -0.50858091504010561 |  -1.01716183008021122 |  -0.24023529720226194 | R | H |   |
|         -9 |   0.00171772002778351 |  -0.52240014793961786 |  -0.50094853768697178 |  -1.00189707537394357 |  -0.26347516068001614 | R | H |   |
|        -10 |   0.00134812839076431 |  -0.52635244838222217 |  -0.49538040052111026 |  -0.99076080104222053 |  -0.28028551280818065 |   | H |   |
|        -11 |   0.00046383214012266 |  -0.53204273788879020 |  -0.48766394847350736 |  -0.97532789694701472 |  -0.30331489957270180 |   | H |   |```
EDIT: So, we surrender when TC falls within [-9, -5] and we stand if TC >= -7 (if LSR is not allowed) or we stand if TC >= -4 (if LSR is allowed).

Sincerely,
Cac

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For what it's worth, I have verified Walker's index numbers for this hand and that my explanation above on how to play it is correct.

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