spanish 21 follow up

Played my stint in the northwest on spanish 21. My play was not that strong- not enough time reviewing basic strategy and casinos would not allow use of basic strategy chart. varied bet with count but not very good on play varations.

Couple questions. CBJN indicates house advantage is 0.40% for H17 with redouble. Does that take into account that player is allowed to keep hitting split aces? I did not think that was typical Spanish 21.

And any idea how much benefit is added when you can redouble for less. Example- double 11 vs 10 on $200 bet. Player gets 2 for a 13. for 1$, you can get another hit. Intuitively I would think this adds a decent benefit over the base Spanish game, but no idea how much. Any guess on much this benefits player?

Blackjack rules allow doubling for less. Not true of Spanish 21.

only drawback. After doubling for less, you could only take late surrender for the "double for less amount".
Ex: $200 bet. Double on 11 vs 10, get a 2 for a 13. Double for less with 1$ and get a 3 for 16. Can take surrender after double but only get 1$ back. At least those were the rules for me.

If the two casinos allowed you to double for less, they clearly violated the game's rules. It is a non-standard practice/procedure. I've personally never encountered it.

played 4 casinos. 2 in the area did not allow double for less. two allowed it multiple times from multiple dealers.
I would suggest you take a closer look if you are in the area.
Pretty sure pit boss observed several times and had no issue.
First letter of casino name = S.

How many times to double? Two or three?

I played sp 21 at four sites. I believe they were all consistent in allowing double, redouble, and a second redouble. I only remember wanting to redouble (must have been 3rd redouble) and they said "no mas". Limit on a redouble was table limit - $300. So $300 bet, place $300 for double, then the redouble was limited to $300.

I'm not clear about the redouble. Do you double and then allowed redouble for less?

Always double for the full amount on the first double. If they'll let you, and you can double for a small enough amount, then double for less can be the correct play for the subsequent redouble(s).

The critical threshold which makes doubling for less the right play is different for every total vs every dealer up card.

I should add that doubling for less on re-doubles can be the correct play, even when the the rule for rescuing a double for less makes rescue impractical. For example, when you keep only the re-doubled amount.

You double A2v6 for the max and receive a 2 which is redoubled for $300 instead of $600, then redouble for another $300 instead of $1200. You've now arrived at the unhappy state of losing 50% of your E.V. because of the capping rule. This means that soft doubling basic strategy needs to be tweaked in order to avoid the redoubling barrier.
You're going to redouble for less on 14vT but only get back half the redouble if you rescue while losing all of the main bet? I would prefer surrendering the original bet.

As I said, even if the rescue rules are such that you would never rescue, re-double for less can still be the right play. The closer to zero you can re-double for, the more it resembles hitting.

On many hands, double for $1 is the obvious play. And intuitively, it sounds like a decent benefit.

any time you have doubled and sitting on 12, 13, or 14 vs dealer 7,8,9,10, or Ace, it should be a gret benefit to hit vs surrender or do nothing. Less benefit on the player 15 and 16 as I would guess the expectation gained vs surrender is not that great.

But I am interested if anyone can try to put a ballpark estimate as to how much benefit added to player. My guess would be around a 0.5%.

Can't give a single number. Depends on how little they will let you re-double for vs money already in play.

It's ratio of the redouble amount to the money already in play that determines the benefit. For a $25 original bet, and allowing 2 redoubles (for a total of 3 doubles) for as little as $1, I have a strategy that yields a 0.66% PLAYER advantage off the top.

my avg bet was probably 25 or 50- so 0.6 or 0.7% sounds reasonable.
it is significant because it makes the house advantage negative.
if you are in the area and don't know which two casinos I observed this, let me know and I can let you know.

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