Odds Methods DEATHMATCH: Percentages v. Ratios v. Fractions

[Crooked Paul]

Hey, can anyone explain to me why so many pro players and commentators use ratios to call odds, rather than fractions or percentages? I myself prefer precentages because comparing them is so easy.

When I hear someone on ESPN say, <font color="blue">He's 2:1 to hit the flush and facing pot odds of 3.5:2</font>, my head hurts. What's the advantage here?


Crooked Paul

P.S. I added a poll question to this so we can see how everyone's preferences break down...

[gaming_mouse]

Paul,

It depends on the situation.

Odds are useful, for example, when you trying to figure out if you have an overlay to make a call. Most players on this site know that when you have, say, 6 outs, you need 7:1 to call. Now when it's one bet to them, all they need to do is look at the pot and see if there are 7 or more bets in it.

Percentages are more natural in other situations.

gm

[Crooked Paul]

It seems like you're saying that ratios are more useful if you've already memorized certain information about how your number of outs relates to your chances of hitting one. Is this accurate?

I suppose this is true of using percentages, too. I have a little trick I use where (outs x 2) is the rough percentage of hitting an out on the next card, while (outs x 4) is the rough percentage of hitting an out with two cards to come (like if you're deciding to go all-in after the flop, and you know you won't face a decision on the turn or river). Knowing these rough percentages, it makes sense to figure pot odds as a percentage as well for easier comparison.

For example, suppose you have a draw on the nut flush on the flop and your opponent puts you all in (if you call). You have 9 outs. The shortcut gives you rough odds of 36% to hit your flush, so if you're being asked to put in 35% or less of the pot's value once you call, you should.

Your actual chances are 9/47 to make the flush on the turn plus the chance you'll miss on the turn but hit on the river, which is (38/47)*(9/46), which works out:

9/47 + (38/47)*(9/46)
= .19 + .81*.20
= .19 + .16
= .35
= 35%

I just went through all that to verify my shortcut for y'all. In practice, it's super-easy to count up your outs and do a simple multiplication to get your hand odds.

Is there some information I'm missing about ratios that makes it even easier than this? Thanks for taking the time to educate me.


Crooked

[d10]

I used percentages when I mostly played online. That's because I could use a calculator and I knew how much was in the pot in terms of total dollar amount at any given time, so it was easy to multiply the % of hitting my draw by the $ amount in the pot and get a figure of the most I can profitably call.

Playing live is different because there's no number floating above the pot that tells you how much is in there. The only easy way to keep track is by counting small bets as they're made, then /2 on the turn and continuing to count in big bets. When you do this there is no calculating, you of course know immediately what kind of draw you're on and what odds you need from the pot to profitably chase, so if your bet count is higher than the necessary odds you can call 1 bet without much thought (and of course it's not too difficult to divide by 2 or 3 if you're up against a raise). I think percentages would be difficult and unnecessary in this situation. It's probably also the way to go online if you're counting bets instead of relying on the $ in pot number, but I'm too lazy to do that.

[Paul2432]

[ QUOTE ]
Is there some information I'm missing about ratios that makes it even easier than this? Thanks for taking the time to educate me.


Crooked

[/ QUOTE ]

Suppose there is $100 in the pot and its $25 to call. Let's say you have a 25% chance of winning the pot which means you need 3:1 odds.

I think in this situation it is immediately obvious that your pot odds are 4:1 which is greater than 3:1 so you can call.

If you were using percentages you would need to figure your percentage as 25/(100+25) = 20%. In this case 20% is less than 33% so you can call.

I think most people find the first method far simpler.

Paul

[topspin]

[ QUOTE ]
Let's say you have a 25% chance of winning the pot

[/ QUOTE ]

[ QUOTE ]
I think in this situation it is immediately obvious that your pot odds are 4:1 which is greater than 3:1 so you can call.

[/ QUOTE ]

Except how did you know that you need 3:1 to call if your winning chance is 25%? Why, you did (100-25):25 = 75:25 = 3:1. This is no more or less odious than figuring 25/(100+25) = 20%.

It ultimately boils down to which form of arithmetic you're most familiar and comfortable with. OP should just go with whatever he feels comfortable with, and not worry about what using the same math as the "in crowd" [img]/images/graemlins/wink.gif[/img]

[Crooked Paul]

d10's comments make a lot of sense to me. I mostly play no-limit games online, where the pot and any bet can have arbitrary (but precisely known) values, so it's easier for me to use percentages. I can easily see that playing a limit game, especially live, ratios make more sense because the pot and any bet are very likely to be whole-number multiples of the BB.

Thanks, d10! By the way, does your name refer to a ten-sided die used for pen-and-paper RPGs? (Yes, I am a nerd.)


Crooked

[d10]

[ QUOTE ]
Thanks, d10! By the way, does your name refer to a ten-sided die used for pen-and-paper RPGs? (Yes, I am a nerd.)

[/ QUOTE ]

Nope, although you're not the first who's asked me that.