SD in BB/hand, rather than BB/100

gaming_mouse · #1 01-29-2005, 06:56 PM

Despite two of the juiciest tables ever, my last two sessions of live 6/12 have been -20/BB and -25/BB, a bad run.

I want to know the chance that a player with a win rate of +2 BB/100 loses 25 BB in a 150 hand session.

I cannot use the PT SD tho, because its unit is BB/100, and with a sample size of only 1.5, the central limit theorem does not apply. I could answer the question, tho, if I had my SD in BB/hand -- a number that will be quite a bit larger.

Has anyone written their own SQL query to calculate that number from a PT database?

TIA,
gm

gaming_mouse · #2 01-29-2005, 07:15 PM

Wait a second.

My SD per hand should just be 10x my SD in BB/100.

Which means it is about 160 BB/hand, right?

Which means that my SE for 150 hands is:

160/sqrt(150), about 13.

This means that the chance of a -25 BB downswing is less than 2%. Is this correct?

uuDevil · #3 01-30-2005, 02:36 AM

[ QUOTE ]
Wait a second.

My SD per hand should just be 10x my SD in BB/100.

Which means it is about 160 BB/hand, right?

[/ QUOTE ]
Shouldn't that be 1/10 x SD? If SD=160 BB/hand, doesn't that mean you lose more than 160 BB ~1/6 of the time in a single hand? But than cannot happen in limit poker.... SD=1.6 BB/hand sounds more like it.

However, your SD is likely different online vs. live. Don't you track your live play?

I think a typical live SD~10 BB/hour for a decent player. In 150/35= 4.3 hrs, SE~2.1*10=21 BB/hr, so your loss is only a little more than 1 SD and will happen ~1/6 of the time. This is consistent with my experience-- 25 BB is not an unusual amount to lose in a live session.

gaming_mouse · #4 01-30-2005, 09:04 AM

[ QUOTE ]
I think a typical live SD~10 BB/hour for a decent player. In 150/35= 4.3 hrs, SE~2.1*10=21 BB/hr, so your loss is only a little more than 1 SD and will happen ~1/6 of the time. This is consistent with my experience-- 25 BB is not an unusual amount to lose in a live session.

[/ QUOTE ]

Let me first say that something was definitely wrong w/ my reasoning. I lost, and then won back, another 25 BB tonight over the course of 10 hours. So surely 2% is not the correct number.

[ QUOTE ]
Shouldn't that be 1/10 x SD? If SD=160 BB/hand, doesn't that mean you lose more than 160 BB ~1/6 of the time in a single hand? But than cannot happen in limit poker.... SD=1.6 BB/hand sounds more like it.

[/ QUOTE ]

Yes. You are right. And then the SE for 150 hands is sqrt(150)*1.6=19.59 Now everything makes perfect sense. 25 BB is barely over 1 SE. My brain must have been taking a nap before.

[ QUOTE ]
However, your SD is likely different online vs. live. Don't you track your live play?

[/ QUOTE ]

I don't see why your SD/100 should be different live. Hourly yes, but not /100. Also, how do you track your live play? I want in on this.

gm

uuDevil · #5 01-30-2005, 04:33 PM

[ QUOTE ]
I don't see why your SD/100 should be different live. Hourly yes, but not /100. Also, how do you track your live play? I want in on this.

[/ QUOTE ]
Maybe you'll find the difference isn't significant, but it is a different game. The stakes may be different. Your relative skill level may be greater. Your opponents may play more loosely and passively. In response, maybe you also play more loosely. Stuff like that.

Mason's Essay on SD