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View Full Version : Re: Odds on Flopping Open-End Draw on Flop

imashyboi
05-05-2005, 07:16 PM
Hi, I just have a question which I can't calculate. Anyone knows the odds of flopping an open-ended straight draw on the flop when holding connectors? (AK, KQ, QJ, JT, T9, 87, etc...)

How about flopping an open-ended straight draw with flush draw when holding suited connectors?

I know the odds of flopping a four flush on the flop is about 6.5-1. Let me know some insight on this, I'm sure some players would like to know as well. Thanks

BruceZ
05-06-2005, 02:38 AM
[ QUOTE ]
Hi, I just have a question which I can't calculate. Anyone knows the odds of flopping an open-ended straight draw on the flop when holding connectors? (AK, KQ, QJ, JT, T9, 87, etc...)

[/ QUOTE ]

We can answer this by starting with the numbers in this post (http://archiveserver.twoplustwo.com/showthreaded.php?Cat=&amp;Number=355216&amp;page=&amp;view=&amp;sb =5&amp;o=&amp;vc=1). Although this calculation is tricky, the numbers in that post are absolutely correct, as they have been derived several different ways by a number of different people. For a suited connector that makes the maximum number of straights, like JTs, we know the following:

1. Flopping 8-out straight draw, including the 8-out double gutshots, (but no flush or straight), 9.60%.

2. Flopping a flush draw or 8-out straight draw, (no flush or straight), 19.1%.

3. Flopping an 8-out flush draw AND straight draw (no flush or straight), 1.2%.

4. Flopping double gutshot, 0.56%.

Now for an offsuit JT, you will flop a straight draw slightly more often than the 9.60% above because you do not have to worry about flopping a flush; however, I will use the 9.60% or 9.4-1 for the following calculations assuming you will be playing suited cards most of the time. This will be the same for all connectors from JT down to 54.

QJ and 43 flop 2/3 as many straight draws as JT, and there are half as many double gutshots, so they flop an 8-out straight draw (2/3)*(9.6% - 0.56%) + 0.56%/2 =~ 6.3% or 14.9-1.

KQ and 32 flop 1/3 as many straight draws as JT, and no double gutshots, so they flop an 8-out straight draw (1/3)*(9.6% - 0.56%) =~ 3.0% or 32.2-1.

AK and A2 cannot flop an 8-out straight draw.

[ QUOTE ]
How about flopping an open-ended straight draw with flush draw when holding suited connectors?

[/ QUOTE ]

1.2% from above.

[ QUOTE ]
I know the odds of flopping a four flush on the flop is about 6.5-1. Let me know some insight on this, I'm sure some players would like to know as well. Thanks

[/ QUOTE ]

It's actually only 8.1-1.

C(11,2)*39/C(50,3) =~ 10.94% or 8.1-1.

binions
05-06-2005, 01:15 PM
[ QUOTE ]
Hi, I just have a question which I can't calculate. Anyone knows the odds of flopping an open-ended straight draw on the flop when holding connectors? (AK, KQ, QJ, JT, T9, 87, etc...)

How about flopping an open-ended straight draw with flush draw when holding suited connectors?

I know the odds of flopping a four flush on the flop is about 6.5-1. Let me know some insight on this, I'm sure some players would like to know as well. Thanks

[/ QUOTE ]

I'd suggest picking up a copy of Mike Petriv's "Holdems Odd Book"

BruceZ
05-06-2005, 01:24 PM
[ QUOTE ]
I'd suggest picking up a copy of Mike Petriv's "Holdems Odd Book"

[/ QUOTE ]

That book has some errors in this area in particular. They don't make a huge difference numerically, but it doesn't count cases where the board pairs correctly.

binions
05-06-2005, 01:39 PM
[ QUOTE ]
[ QUOTE ]
I'd suggest picking up a copy of Mike Petriv's "Holdems Odd Book"

[/ QUOTE ]

That book has some errors in this area in particular. They don't make a huge difference numerically, but it doesn't count cases where the board pairs correctly.

[/ QUOTE ]

I know there are some double counting errors in Petriv's book, but by and large it is an excellent book for beginner.

Here is what I have come up with in terms of flop odds:

Unsuited Max Stretch Connector (JT-54)
1.22% flop a straight w/o a 3 flush board
1.31% flop any straight
1.91% flop 2 pair w/o a 3 flush board
2.02% flop any 2 pair
1.45% flop trips or full house or 4 of a kind
8.51% flop clean 8 out straight draw (open ended or DBB with no paired/no 3-flush flop)
9.71% flop any 8 out straight draw (open ended or DBB)
13.09% flop a hand worth playing
6.64 to 1 against

Unsuited Max Stretch 1-gap (QT-53)
0.92% flop straight on non-3 flush board
0.96% flop any straight
1.91% to flop 2 pair on non-3 flush board
2.02% flop any 2 pair
1.45% flop trips or full house
6.18% flop clean 8 out straight draw (open ended or DBB)
7.02% to flop any 8 out straight draw
10.46% to flop a hand worth playing
8.56 to 1 against

Suited Max Stretch Connector (JT-54)
0.84% flop a flush
1.22% flop straight w/o 3-flush board
1.30% flop any straight
10.94% flop a four flush
7.21% to flop clean 8-out straight draw (unpaired board, no 3 flush against, no 4 flush for)
1.85% flop clean 2 pair (no 3 flush board)
2.02% flop any 2 pair
1.45% flop trips or full house or 4 of a kind
23.51% to flop a hand worth playing
3.25 to 1 against

Suited Max Stretch 1-Gap (QT-53)
0.84% flop a flush
0.92% flop straight w/o 3 flush board
10.94% flop 4 flush
5.29% flop clean 8 out straight draw
1.85% flop clean 2 pair
1.45% flop trips or full house or 4 of a kind
21.29% to flop a hand worth playing
3.70 to 1 against

Suited Max Stretch 2-gap (KT-52)
0.84% flop a flush
0.61% flop a straight w/o 3 flush board
10.94% flop a four flush
2.79% flop 8 out straight draw
1.85% flop clean 2 pair
1.45% flop trips or full house or 4 of a kind
18.48% to flop a hand worth playing
4.41 to 1 against

Suited Cards w/no nut straight potential
0.84% flop a flush
10.94% flop a four flush
1.85% flop clean 2 pair (no 3 flush board)
1.45% flop trips or full house or 4 of a kind
15.08% flop a hand worth playing
5.63 to 1 against

Small to Mid Pairs
11.8% to flop a set or better
1% to flop a four straight (not idiot end)
12.8% to flop a hand worth playing - 6.8 to 1 against

imashyboi
05-10-2005, 09:15 AM
Hey BruceZ, do you happen to have AIM? Its probably easier if I just message you online. Let me know since I have other questions regarding some stats as well. Thanks

Evan Evans
05-21-2005, 03:49 AM
Actually the pot equity based on the odds should be discounted to take into account MAKING your flushes and straights by the river. So a suited connector really is only worth 12.8% approx preflop to play.