"simple" Math Question re youtube hand

#1 August 29th, 2018, 6:22 AM

Math confusion.
From youtube..

Ng- 7d 4d
Negreanu - Js 9s

Flop: 4h 3d jd

Equity calculator on screen shows about 50% for each player.

So lets say Ng has 9 diamonds plus 2x4s and 3x3s to make her hand.. 14 outs.

Thats 14/47 (about 30%) plus 14/46 (about 30%) giving about 60% in total.

Also, with Daniel on the turn he has 33/47 (about 70%) plus 32/46 (about 70%) on the river.

Why don't we add those two together like we did with Ng's hand?

Se calculate Ngs equity twice (two cards to come)

Why can't we count Daniels equity twice? Obviously we can't because it comes to 140%.

What am I not understanding here??

Adam

#2 August 29th, 2018, 6:36 AM

Because the the 2-4 rule is imperfect. And becomes less the perfect the more outs and streets we have.

For instance for 3 outs it�s works fine. For 13 it doesn�t. It�s just for quick at table calculations.

#3 August 29th, 2018, 7:36 AM

Originally Posted by gingang_76

Math confusion.
From youtube..

Ng- 7d 4d
Negreanu - Js 9s

Flop: 4h 3d jd

Equity calculator on screen shows about 50% for each player.

So lets say Ng has 9 diamonds plus 2x4s and 3x7s to make her hand.. 14 outs.

Thats 14/47 (about 30%) plus 14/46 (about 30%) giving about 60% in total.

Also, with Daniel on the turn he has 33/47 (about 70%) plus 33/46 (about 70%) on the river.

Why don't we add those two together like we did with Ng's hand?

We calculate Ngs equity twice (two cards to come)

Why can't we count Daniels equity twice? Obviously we can't because it comes to 140%.

What am I not understanding here??

Adam

The simple answer is because Negreanu is ahead. The rough odds calculation for the next two Streets represents Ng's chances of winning assuming that the Turn doesn't hit Negreanu. Your estimate covers that: 30% Ng + 70% Negreanu = 100%.

If you use the (flawed) 2/4 chances of Ng on either Street, it is 28/56. The rough estimate of the outs misses by quite a bit.

CC's calculator says that Ng has a 51% chance, and Negreanu has a 49% chance - not 56% to 44% like 2/4 tells you (or 60% like your out count estimate). This is because the Calculator doesn't assume a card on the Turn that doesn't help Negreanu, it considers all possibilities.

#4 August 29th, 2018, 7:49 AM

The really interesting question) by the Way also noticed this sometimes, but did not elaborate. We will wait for a sensible answer))

#5 August 31st, 2018, 4:51 AM

The cards Daniel can get on the turn don't beat a flush for one thing, only a smaller two pair. A blank on the turn is absolutely zero help to him in any way.

#6 September 3rd, 2018, 2:38 PM

Probability Negreanu has best hand on the turn 33/47 and the river 32/46 = 33/47*32/46 = 49%

Probability Ng has best hand on the turn 14/47 or the river 14/46 = 14/47 + 14/46 = 60% (or by rule of 4x = 4*14 = 56%

So Ng is given two street opportunity to out match Negreanu, while Negreanu has to hold both streets without possibility to improve to more nutted hand than Ng so in essence Ng�s outs are pure outs for 2 streets.

Imo (not sure at all) we can get better approximation by disregarding 7 as an out, because it�s just as likely that Negreanu will get 9 for 2pairs, thus 9 and 7 are cancelling each other away, giving Ng 11 outs = 44% => 11/47+11/46 = 47%

This is obviously just guessing around without any kind of deep knowledge.

Also not sure about divider, we know 7 cards, thus we have not seen 45 cards, so 11/45 + 11/44 = 49%

"simple" Math Question re youtube hand

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