The anatomy of a flop

Note: Not at the old Poker1 site. A version of this entry was originally published (2008) in Casino Player.

Usually, we concentrate on strategic poker concepts and player-versus-player psychology. Recently, though, we took a look at hold ’em odds. I showed you how to do basic calculations, but I stressed that you really don’t need to learn that skill.

Instead, you should just let me and other obsessed poker researchers do the analysis for you. Then you can simply memorize the published results.

Fine. Let’s go a step further. Many hold ’em players seem to have a poor expectation regarding what will happen on the flop. This time, I’m not going to provide detail on the math. But I am going to do something more valuable. I’m going to give you the anatomy of a flop, so you know what to expect from the possible 22,100 ones that might appear.

Here it is, quick and simple…

A selective table of flop odds

 Flop event Odds against Likelihood Comment You hold a pair, and at least one more of your rank flops 7.5 to 1 11.8% This is why small pairs often are unprofitable. Usually, you’ll either need to connect on the flop or surrender. You begin with K♣ Q♦ (or any non-pair), and you flop at least one pairing rank 2.1 to 1 32.4% You’ll be successful in pairing almost a third of the time. You begin with suited cards and either flop a flush or two more of your suit 7.5 to 1 11.8% Most players expect this to happen more often. The odds are actually about the same as flopping trips or better when you begin with a pair. It’s much more likely that you’ll see two, not three, of your suit flop and have only a flush draw. It’s 118 to 1 against flopping a complete flush. You hold an ace and flop an ace 4.8 to 1 17.3% The more resistance you meet before the flop, the less likely an ace is to flop, because the chance is increased that an opponent also holds an ace.

More winning stats

The reason that’s called “a table of partial odds” is because there are many more interesting and important things that could go into a complete flop anatomy. For instance, here’s the likelihood of suited cards appearing on the flop, assuming you have no knowledge of anything anyone holds, including yourself: Three different suits, 39.8%; exactly two cards of the same suit, 55.1% ; all three cards suited, 5.2%  (odds are 18 to 1 against a suited flop); at least two cards suited, 60.2%.

And what about paired flops? This is the breakdown, again assuming you have no knowledge of any cards in individual hands: Three different ranks, 82.8%; exactly one pair 16.9%; three-of-a-kind, 0.24%  rounded (or precisely 424 to 1 against); at least one pair, 17.2% (or about 4.8 to 1 against).

Even though we could go on listing probabilities, what you’ve just learned constitutes a decent anatomy that helps you better predict your fate on your next hold ’em flop.— MC

Mike Caro

Known as the “Mad Genius of Poker,” Mike Caro is generally regarded as today's foremost authority on poker strategy, psychology, and statistics. He is the founder of Mike Caro University of Poker, Gaming, and Life Strategy (MCU). See full bio → HERE.

6 thoughts on “The anatomy of a flop”

1. Anonymous says:

In your lesson there is about K ¨ Q§ – May you please xplain those signs ¨ §
Never saw them anywhere before.
Why these responses to this lesson seems to have so little to do with the subject ??,
I’m along with the responses wherever or why they come from
Had 50€ left on my overdraft 3 days ago – Back on 5.000 + today :-)
Scared money, I learn to play poker where I can and it’s online mainly freerolls
!
Why in the last 2 weeks each time I reach final table,
Have to restart my computer ?
Now that my last? cartige of the year is shot and would love to get to play for real Is playing on live secure?

Ok I just wanted to talk a bit

but about the § and ¨ ?

2. bk says:

LOL @ the comments!!! (I know they are old) “Just today I have lost so many hands when I was totally ahead on the flop, and on the turn!” <–well, then it MUST be rigged because one day of you playing is a 100% acceptable sample size!

You ever notice players don't claim things are rigged when they are winning?

bksportsblog.com

3. Anonymous says:

Can you post for connectors. Suited and not?

4. WYZ says:

yes it is a problem with PokerStars, and I have the same problem here no matter odds, it matters only to have the best hand on the Floop and if possible to complete the turn and river

5. Luke M. says:

Daniel, I have to agree 100%! I have played on PokerStars for over 1.5 years, and the odds spoken about and predicted/proven on here are totally null on PokerStars… Just today I have lost so many hands when I was totally ahead on the flop, and on the turn! I would flop a set, someone would runner runner a straight/flush on me, I would make a straight on the turn, they would river a fullhouse! All these odds calculations do not exist in online poker — only in live card games. I believe 100% that online poker is rigged because of the software. It has proven time and time again to me, software always plays against someone who plays solid poker.

6. Daniel M says:

Mike, since you seem to be a man of odds why don’t you along with Doyle do a story on how Poker Stars in there freeroll tourneys and regional tourneys go completly and consistantly against all the odds you have ever spoke of when it comes to their cards whether it’s the flop, turn or river. Yes, I do know why this is… it’s called business.