Here on cardschat website, thay have a lot of content about odds and stuff. But what I consider using with certain frequency on the tables is the rule of 2, that is, you count your outs and multiply them for 2 and you get your percentage of winning a hand. It's very wasy to aply and it's the simplified formula of the missing outs, which is an advanced calculum used for more experienced players. This calculum is based not on your chances of winning, but on your chances of losing a hand, and its like:
1 - (missing odds on turn x missing odds on river)
I'll give you and example:
you
fold an
and the flop comes
, so you've got a nut flush draw here.
...did you mean to write 'hold' here? Not sure how you can be on any type of draw without a hand. Anyway, you are not on a nut flush draw. You are on just a flush draw + gutshot draw. A heart can improve your hand, but it can also improve other better flushes as well. You also have 3 Qs you can draw to give you a straight as well. So, you have 12 outs here.
The odds of the missing cards in the turn are 38 of the 47 unseen left, and in the river, if you dont hit a heart on turn, is, 38 of the 46 unseen left. Putting these values on the formula will give you something like
1 - (38/47 x 38/46) witch will turn into something like
1 - (0,8 x 0,82)
1 - (0,656) = 0,344 or about 35% for easy math.
...This is correct, you have a ~35% chance to hit on the turn or river with 9 outs. You essentially get the same results whether or not you figure out the odds of you hitting or you missing. So, it really depends on which is easier for you as a player.
And using the rule of 2 it's like, we have the turn and river yet, and in each one of these community cards we have 9 outs (the other hearts), 9 on turn and 9 on the river, so we have a total of 18. Using the rule of 2: 18x2=36, which turns to be a percentage, so, 36%.
...not exactly. You have 12 outs (as shown above), but your outs don't double on the turn and river. You have 12 outs to hit on the turn, 12 outs to hit on the river if you miss the turn.
We only use the rule of 2 if we are looking at each individual street. A basic and easy rule to follow is: Is there the possibility of betting on the next street? If the answer is yes, then we use the rule of 2. With 12 outs on the flop, 12 x 2 = 24, which means we have a ~24% of hitting an out on the turn. If we want to get a little more precise, it's x 2, +1. So, 12 x 2 + 1 = ~25%
If the turn bricks and we are facing another bet, the same rule of 2 applies which gives us ~25% chance to hit our out on the turn-to-river card.
Now, if there is no possibility of future bets-for example, your opponent is all in on the flop, then we are guaranteed to see both the turn and river. Now we follow the rule of 4. 12 x 4 = ~48% chance to win on either the turn or river. It's actually lower at ~45%, but for quick math, it's close enough.
Whether we're calling on the bets depends on the hand odds vs pot odds. We can use either the ratio method or the percentage method.
If using the percentage method, then if our hand odds equity > pot odds percentage, it's a profitable call. So, if we're looking at 25% equity to hit one of our 12 outs on the turn, our pot odds needs to be <25% in order to call.
If using the ratio method, then the pot odds > card odds for it to be a profitable call. So, if we have 12 outs on the flop, there are 47 unseen cards, 12 help us, 35 dont. So, our ratio is: 35:12 = ~3:1 odds we hit. So, we need our pot odds to be greater than 3:1 in order to make a profitable call.
Hope i have helped you cause i use this a lot and it have already helped me a lot on many cases.
Good luck on tables man
