waddayasay: what percentile am I on??

[waddayasay]

I am a casual green chip basic strategy blackjack player in Caesar's Atlantic City and Bellagio Las Vegas. I keep precise notes of my play: I am up 3000 dollars in 60 hours of play. I estimate I played 4000 hands, at a 0,5% disadvantage. According to these figures I should be down 500 dollars. Can anyone help me calculate what percentile am I on?

[Don Schlesinger]

> I am a casual green chip basic strategy blackjack
> player in Caesars Atlantic City and Bellagio Las
> Vegas.

Do you flat bet $25? I'll have to assume that for the calculation, although it probably isn't the case. If your average bet is higher, then we'd have to know what it is.

> I keep precise notes of my play: I am up 3000
> dollars in 60 hours of play.

Lucky you! :-)

> I estimate I played 4000
> hands, at a 0,5% disadvantage.

It's not quite 0.50% disadvanatge for the two games you mention; it's more like 0.44% -- assuming you don't play the best 0.26% game at Bellagio.

> According to these
> figures I should be down 500 dollars.

OK, so I see you used $25 bets. That helps.

>Can anyone help me calculate what percentile am I on?

Sure. 4,000 hands of play at $25 is $100,000 worth of action. At house edge of 0.44%, your loss should be $440.
Standard deviation for one hand of BS play is, roughly, 1.15 times bet size, or $28.75. As s.d. is a square-root function, the square root of 4,000 is 63.25, so one s.d. is 63.25 x $25, or $1,581.25.

Your $3,000 win is $3,440 above your $440 expected loss. So that represents a 3,440/1,581.25 = 2.18-s.d. win. Probability for such a departure from the mean is 1.5%, or, roughly, once in every 67 tries.

So, if 67 people went out and played exactly as you did, only one of them would be as lucky as you. :-)

Be happy you were the one, but ... don't expect it to continue! :-)

Don

[ShoelessD]

How many comp points did you get for your play?

[Norm Wattenberger]

Where you stand on the curve:



The ninth calculator (Actual) on the CVCX Online site can calculate this for you. Entering 140 units Won, -.44 win rate for 100 hands, 11.5 standard deviation for 100 hands and 4,000 hands, the calculator returns 1.51%.


CVCX Online