A few random questions

If you can please give me your thoughts on any of the following, I'd appreciate it:

1) What do you think is the worst double-down play dictated by Basic Strategy (e.g. A,7 vs 3)?

2) Which of the following do you think are good covers for a counter:

a) Speaking your plays (e.g. saying "Hit") instead of using hand signals

b) Attempting to hand your money directly to the dealer rather than placing it on the table when requesting chips

c) Doubling-down for less (e.g. with a $25 bet, double-down for $20)

d) When playing 2 spots, bet different amounts on each

3) Is it preferable to dress better or worse? (I don't mean wearing a tuxedo vs wearing a tank-top and shorts, but more like wearing a shirt that you'd wear to the office vs wearing a T-shirt more appropriate for shopping at Home Depot.)

4) Does playing 2 spots (without halving your bet) double your risk-of-ruin?

Thanks!

I think many of the soft doubles, especially like A2 vs5, also doubles like 9 vs 3 give little edge.

Looking like a novice when you first sit down may give the first impression that you want to give and first impressions are valuable. It might disappear though because of your not making dumb novice plays.

I tend to dress to blend into the type of crowd. Two years ago during rodeo week in Vegas, this native of The Bronx bought himself his first cowboy hat since he was 6 years old or so. The accent needs work though.

I am not sure what you mean by "worst" soft doubles. Certain soft doubles give relatively little added EV (vs hitting or standing) and increase variance a fair amount. If this is the criteria for "worst", then I could take a guess,but you would be better off relying on the math as this can be easily quantified.

As for cover, your appearence and mannerisms at the table should fit into an overall image that you are trying to portray. Typically, you should try to make it easy for the pit to stereotype you into a category of player that they do not fear, such as the following:

High roller
Drunk, clueless kid
Compulsive gambler
Stupid tourist
etc

Once you have selected an appropriate image, then dress and act accordingly. You should take the venue into account when selecting an image.

Also, if you are a low roller for a particular casino, then limit your camo to appearance and behaviour. There is no reason to give up EV with playing/betting/drinking camo since you will likely be ignored anyway.

1) What do you think is the worst double-down play dictated by Basic Strategy (e.g. A,7 vs 3)?

You'd have to define "worst" but I'd say the ones with indices closest to zero (A2v5 and A4v4, for example). 10v10 (not basic strategy) could be considered a "bad" double unless you are well above the (EV-maximising) index.

2) Which of the following do you think are good covers for a counter:

a) Speaking your plays (e.g. saying "Hit") instead of using hand signals
b) Attempting to hand your money directly to the dealer rather than placing it on the table when requesting chips

Might be good for short sessions where you play infrequently but quickly lose their value if you show yourself to be a good player.

c) Doubling-down for less (e.g. with a $25 bet, double-down for $20)
d) When playing 2 spots, bet different amounts on each

I don't like cover that sacrifices EV.

3) Is it preferable to dress better or worse? (I don't mean wearing a tuxedo vs wearing a tank-top and shorts, but more like wearing a shirt that you'd wear to the office vs wearing a T-shirt more appropriate for shopping at Home Depot.)

They say that the prototypical counter under-dresses rather than over-dresses, so all other things being equal I'd say dress better. It depends on a lot of other things though.

4) Does playing 2 spots (without halving your bet) double your risk-of-ruin?

No, less than double due to covariance. Conventional wisdom is that you should keep ROR at a level you are comfortable with and adjust other factors accordingly.

I am not sure what was meant by the question:

�What do you think is the worst double-down play dictated by Basic Strategy (e.g. A,7 vs 3)? �

I don�t know what �worst� it. However A8 v 6 has some interesting qualifications for this honor.

Although it is BS in H17 games, it will bring heat! Getting heat from a BS play is bad from a card-counters point of view.

Griffin notes that A8v6 in SD, S17 games is a double, but it is a very close play. I once did a little study that showed, if your had a card, then not doubling was a better choice for the BS player.
With Risk-Aversion, this probably isn�t even BS. That is, a card counter who is spreading but get A8v6 off the top of the deck possibly should still stand. I would have to run some numbers before I could say for sure.

A similar play is A2 v 5. This is NOT a double in infinite decks, but it is in 8 decks. However, in 8 decks, and mybe even 6, the gain is so small that RA strategy would usually have you not double off the top of the deck.

Regarding your question on Risk of Ruin: Does playing 2 spots (without halving your bet) double your risk-of-ruin?
RoR is not linear Doubling your bet does not double your RoR.

However, something you could ask about is the �Bank Needed�. That is, I may want to compute what size Bank I need to maintain some given RoR, like 5%. Then doubling your bet on one spot does double the required bank; doubling ti on two spots does not.