Rule of 4 and 2.

I was watching a poker show on tv and it was on odds and outs. There was a segment thats really cool and gives you your precent to win the hand post flop and post turn. You take your outs post flop and times by 4. That gives you your percent to make a hand with the turn and river cards. After the turn take your odds and times by 2. That gives your your odds to make a hand on the river. Ive tried it in my ring games on pacific latley and its really helped me know when to fold and when to call try it and tell me what you think.

The true odds are going to be up to a couple of percent out from that, but it's a rule of thumb that's good enough for all but the most marginal decisions. It was posted in a poker magazine as well, if I remember correctly. The version that's been posted on here is slightly revised from that very simple rule (to try to get a slightly higher accuracy), but for new players just sticking with the 4x outs for odds after the flop and 2x outs for odds after the turn is easy to apply and much better than not having a good idea of your odds. After this point there's probably more value in learning to spot when your likely outs are reduced (e.g. flush cards removing a possible straight card from being an out worth considering), as this is probably more valuable than 1-2% deviation from the true odds.
Once you're very comfortable with that, then perhaps consider memorising the true outs, so you know values accurate to the nearest percent, rather than approximations.

The rule of 4 and 2 is pretty good. I use it myself when I play. The only thing you have to factor in is for the rule of 4 add 2-4% onto that number and for the rule of 2 take 2-4% off that number you came up with. I found out about this little trick from Phil Gordons "Little Green Book". In this book he has a complete chart on this with exact %. I will try to post it on this thread after I get off work around 5pm.

Although the "rule" as such is close enough, the bigger mistakes are usually made in overcounting your outs, not in figuring out how much each of them are worth.

E.g, K-Qo on a board of 10-9-4, rainbow, two other players in pot. Preflop, you raised in middle position, button 3-bet and the big blind cold called, and you called. After the flop, the blind and yourself checked, button bet, blind called and it's back to you. What's your chance of winning?

about 7 clean outs. so 30%ish. ---RE. F Paulson's question above.

I take:

Flop: (#outs x 4) - 1
Turn: (#outs x 2) + 1

margin of error about +/- 1%

Sorry I havnt put the actual list on yet. Very busy with the NHL finals last night. Will try today as best as possible.