chances of flopping a straight with J9

#1 09-23-2005, 06:23 AM

just trying to sharpen my math skills here. i picked a random hand and wondered about the chances of flopping a straight with this hand. im sure i went wrong somewhere, but is 0.66% anywhere near close?

J9 can flop 3 straights, right? (using BOTH cards) 7-J, 8-Q, 9-K. the chances of flopping a straight using any of those boards is 0.32%, correct? this is purely for curiosity and would appreciate any replies *COUGH BruceZ COUGH*

BruceZ · #2 09-23-2005, 06:48 AM

[ QUOTE ]
just trying to sharpen my math skills here. i picked a random hand and wondered about the chances of flopping a straight with this hand. im sure i went wrong somewhere, but is 0.66% anywhere near close?

J9 can flop 3 straights, right? (using BOTH cards) 7-J, 8-Q, 9-K. the chances of flopping a straight using any of those boards is 0.32%, correct? this is purely for curiosity and would appreciate any replies *COUGH BruceZ COUGH*

[/ QUOTE ]

0.327% per straight is correct, times 3 possible straights gives about 1.0%, not 0.66%. That assumes you are including straight flushes if the J9 is suited. 4*4*4/C(50,3) = 64/19600 =~ 0.327%. Multiplying by 3 straights gives about 1.0%.

#3 09-23-2005, 06:54 AM

on mike caro's site he uses QJ as an example and has two boards where you can flop a straight. he came to 0.65%

wow, how'd i get 0.66% then.. bad addition, i guess. so how'd mike get that number for QJ? .327 + .327? if that's the case, then i should've had .98%, right?

BruceZ · #4 09-23-2005, 07:06 AM

[ QUOTE ]
on mike caro's site he uses QJ as an example and has two boards where you can flop a straight. he came to 0.65%

wow, how'd i get 0.66% then.. bad addition, i guess. so how'd mike get that number for QJ? .327 + .327? if that's the case, then i should've had .98%, right?

[/ QUOTE ]

Right, 0.98% for 3 straights. QJ can also flop 3 straights (89T, 9TK, TKA). If you only consider 2 of the straights, then it is 0.65%. KQ can only flop 2 straights. If you give a link to Mike's site, I'll take a look at it.

#5 09-23-2005, 07:26 AM

thanks for the replies, Bruce. i'd be lost without you if i had to do math on my own at 7 am EST hehe. sometimes it's just not clicking. on Caro's site, he does have .98% for any flop containing a straight using QJ, i just happened to be looking at a part where he was only using KT9 and T98 flops.

im a long time lurker, btw, and i like to browse this forum to improve my thinking when it comes to poker-related math (or math in general).

MickeyHoldem · #6 09-23-2005, 07:28 AM

I think the OP is refering to the following table...
Mike Caro's Link
If you look quickly at the notes column, it could be confusing...