converting percentages to odds

[trenhes]

This is killing me. How do you convert say 40% to odds?
What would the math look like?
I've tried to figure it out using easy numbers such as 10%, but when I get to odd numbers such as 17% or 28% I have no idea. I'm sure one of you math gurus can show me.
In Ken Warren's book he says "When your hole cards are not suited, you will flop a four-flush 2.245% of the time. Odds: 43.54 to 1.
How does he arrive at this?
I find the math as fascinating as the cards.

Thanks in advance for any replies.

[DASH7]

The way I usually do it is 100 divided by your percentage minus 1 to get your odds. Example:
40% chance
100 divided by 40=2.5
2.5-1=1.5
odds are 1.5 to 1

2.245% chance
100 divided by 2.245=44.54
44.54-1=43.54
odds are 43.54 to 1

hope this helps

[HalfSugar]

I think you are wrong Dash I'm afraid

The quickest and best way to do this is to say 'How many times will the percentage divide into 100'. 40% will divide into 100 2.5 times so the odds are 2.5:1.

This works for ALL precentages, a harder example would be say 37%, which will divide into 100 2.702702 times. Obviously this is not practical to do in ur head so if u remember that 33% goes in 3 times, u can see that anything slightly above this will make odds slightly below 3:1. To be honest, could u calculate a 37% odd while sat in a game? Probably not, as long as u know a rough percentage, u can divide it into 100 and get ur odds.

Further examples if needed:
10% - 10:1
20% - 5:1
50% - 2:1
90% - 1.1:1

That is the 100% correct method

- Geno

[Adamm]

Also, just in case ya didn't know...
Changing a % to a probability or vice versa: you just move the decimal over two spots.
50% = .5 probability
4% = .04 probability

[trenhes]

Thanks guys, but when you think about it a 10% chance isn't 10-1 odds it's a 1 in 10 chance of an event happening.
Wouldn't a 50% chance of something happening be 1-1 odds. 50% of the time your coin would be heads, 50% of the time tails.

If you figure Nash's way it comes out to what Warren's book says.

33% chance would then be 2-1 odds. There's 3 things that could happen,
the 66% would be 2 and the other 1 would be the 33%.

I think. LOL

Thanks for the replies and any additional.

[HalfSugar]

No, were talking odds here rather than how many times u r gonna get a 'good' outcome. Yes, 50% does mean it's 1 good, 1 bad outcome so the odds are 2:1 not 1:1. 1:1 implies that it happens 1 in every 1 time, so EVERY time (or 100%).

I guess it's up to u how u think of it, I wouldn't get confused with the other method tho, ur best to stick to wot Adam & I suggest otherwise u could find urself making decisions based on incorrect odds.

Anyway, I'm pretty sure u even talk urself out of the dodgy method:

but when you think about it a 10% chance isn't 10-1 odds it's a 1 in 10 chance of an event happening.
Wouldn't a 50% chance of something happening be 1-1 odds. 50% of the time your coin would be heads, 50% of the time tails.

So ur 10%, under the dodgy method, would in fact be 1 in 9 but u call it 1 in 10..... Think about it, the truth is that 1 out of every 10 times u get a 'good' result so it's 1:10.

I hope this clears it up 4u, remember that u can do things however u want in the end but this is perhaps the clearest way to do it.....

- Geno

[trenhes]

Thanks. If I knew for sure I wouldn't have posted. I'm probably getting mixed up in terminology. There is so much to learn. I don't try to play strictly by the numbers because I don't know the numbers that well, and as you said if I'm playing them wrong that's no good. Thanks again.

[DASH7]

Sorry Genocidal, I got to disagree with you. Trenches is right about a 50% chance being 1:1 odds or in other words paying off $1 for every $1 bet(still getting your original dollar back-for example a payoff in blackjack is 1:1.). If you think a 50% chance pays off at 2:1 odds, I would love to wager you with flipping a coin, if you pay me 2:1 odds or $2 every time I hit heads and I pay you a $1 each time I hit tails. In the long run I'll make money. That is how Vegas makes their money. They pay lower odds than what the actual chance of something happening is. Craps is a prime example.
Unfortuneately, I'm at work now but I have some books at home that explain this better. I'll look some up over the weekend and hopefully I can explain better.

[HalfSugar]

As much as I appreciate ur preaching, my way is the way 99% of poker players would work out the odds while sat at a table. When I denote 2:1 I am not saying it pays $2 for a $1 bet, I'm saying it happens 1 in every 2 times. If u read my posts properly u'd know this

It's all semantics anyway at the end of the day, do woteva u feel is comfortable if it comes out correct 8)

[DASH7]

Believe me, I'm not preaching. I am just stating what I know about odds and I am still pretty new at this poker thing and am more than willing to learn. Most of what I know about odds are from Las Vegas, and horse racing. You are right-it is probably just semantics. Hope to see ya at the freeroll tourney on Saturday. :D

[HalfSugar]

I do apologise for saying that, it sounded very assholey. There's nothing to say I'm 100% right so I'll concede that we both are

I will be at the freeroll..........it'll be my first poker game since September

[dave0044]

When I play poker I like to think of odds in my in the 1 out of X chance of happening format. I think it works easier that way, especially when considering pot odds and such. I know other games in the casino will give payout rates, or you'll find the payout rates for a particular game somewhere online. This is where the other format, the 1 : 1.X would be useful, so you'll know how much money you stand to lose. Also some types of sports betting, particularly baseball, will use a similar format. They give a number for the underdog team, and you can think of that as the amount that they will pay out for a $100 bet. For the favorite team it is the opposite; a bet of the listed number will pay out $100. Its a good format for many types of betting, but poker is a game where math skills are important during the game, so I think the 1 out of X format is easier for for figuring out odds in my head. I usually convert fractions to percentages in my head though, so it doesn't even matter.

[sceadu]

I've always thought ratios were like:
#against:#for

And to go to a percent it's like:
#for/(#for + #against) -- it gets flipped.

So, 1:4, to be a percentage, would be:
1/(1+4) = 20%.

That's how I do it, anyway. It's easier to work with in my head, when counting up outs and with pot odds.. all I have to do is count up the cards or chips, and divide with a good ol' whole number, not trying to shove numbers into and out of 100.