Quote:
Originally Posted by Nichlemn
This seems wrong for the reasons browni listed. Sure, the majority of Kx hands aren't profitable, but the majority of random hands aren't profitable either. Kx has a ~14% chance of turning into the solidly profitable hands KK or AK, whereas random cards have a much lower probability of turning into a premium hand (~2.5% for QQ+, AK).
I had a rethink about the strategy after posting and realised I was being way too nitty, due to my horrible understanding of basic probability. Hopefully my schoolboy maths will fare better in this reply, or I'll have to give up poker.
If we completely ignore the EV of specific hands and just look for playability (e.g. we consider AA and JTs to be equally playable, even though they are, in fact, massively different in value), then we can formulate a discard strategy based on the probability of getting a playable hand from a 'standard' range, as touched upon by whosnext in post #8.
e.g. Suppose hero is UTG at 6-max, and his arbitrary/standard playable range is 66+,A2s+,K9s+,QTs+,J9s+,T9s,AJo+,KJo+ (just under 15%).
Obviously, the chance of hero being dealt a playable hand in that seat is 14.93%, so after looking at the first card, hero should calculate the probability of getting another "useful" card if he keeps it, and compare that with the probability of getting a playable hand if he discards the first one and takes two at random (which we already know is 15%).
All aces are obviously kept, since almost 50% of the desired range contains an ace, so you're halfway to having something playable when your first card is an ace. A nearly 50% chance of having a playable hand (instead of the 15% chance with two random cards) makes an ace a clear keeper.
For other cards, I arbitrarily decided to use hearts as the suit of the first card, in order to make counting playable combos easier.
If hero is dealt the king of hearts, what is the probability that the second card will make his holecards playable? His "outs", as it were, are 4 aces (to make AK), 3 kings (KK), 4 queens (KQo/KQs), 4 jacks (KJo/KJs), plus the ten of hearts (KThh) and nine of hearts (K9hh). These outs total 4+3+4+4+1+1 = 17 out of the 51 cards left in the deck. In short, when hero is dealt a random king in this spot, he has a 17/51 = 33.33% chance of his second card making the hand playable.
Since this 33.33% figure is higher than the 15% chance of getting a playable hand from two random cards, the strategy with a king UTG would be to keep it, not discard.
How about Qh? The outs are 4 aces (AQo/AQs), 4 kings (KQo/KQs), 3 queens (QQ), plus Jh, Th (QJhh, QThh) = 13/51 = 25%, so a queen should also be kept, not discarded.
Jh? 4 aces, 4 kings, 3 jacks, Qh, Th, 9h = 14/51 = 27% => keep a jack too.
Th? There were no offsuit combos containing a ten in the arbitrary range, so the outs are 3 tens, Ah, Kh, Qh, Jh, 9h = 8/51 = 15.7%.
Amazingly,
when dealt the ten of hearts UTG, we'd still be better off keeping it (15.7% chance of getting a playable hand) instead of discarding and having two at random (just under 15%).
The 9h would have 3 nines, Ah, Kh, Jh, Th = 7 outs, so this would be discarded as 7/51 = 13.7%.
You could do similar simple probabilistic calcs with the wider ranges for other positions. It would be quite interesting to look at, say, a 40% range for the BTN. Taking card removal effects at this juncture would be going a bit too far imo.
Note: I may have made some stupid combo-counting errors (it's late and I'm tired) but I think you get the point.
Quote:
Originally Posted by Nichlemn
For what you're saying to be true, the overwhelming majority of your winnings would have to come from AA and that's not the case.
I might address this (the actual EV of specific hands) at a later date, because it's actually kinda frightening just how profitable AA is in comparison to other playable hands.