On confidence intervals

[elindauer]

Hi pfkaok,

You make some great points, and you're dead on. Confidence interval calculations certainly have merit. It's just that this math has been used as a claim that you can't know that you're winning unless you have a half million hands in your database, and that's just not true.

I particularly like your points that confidence interval calculations can be very surprising for noobies, and that it is easy for players with limited experience to misevaluate their opponents' mistakes. You got it. I think good advice here is that you should not consider players being too TIGHT, too AGGRESSIVE, or too PREDICTABLE to be making mistakes in your first year at least. Loose mistakes and passive mistakes are the ones you should count, until you're playing, say, 30-60 on a daily basis. I honestly still haven't figured out what mistakes a so-called "weak-tight" player is making if he isn't playing tight-passive. I suspect it's possible in a very tough high limit game and means a player who doesn't, for example, ever 3-bet light preflop or make similar moves with very weak cards in late position (see any mikel post for non-weak-tight play in a high limit game).

Of course, evaluating your own game requires a kind of brutal self-honesty that perhaps is hard to find. If you have any doubts and really want to know, get someone you respect to look at your hands and tell you how good you are. You'll find this much faster and almost as accurate as playing a million hands and looking at the results.


Good luck.
Eric

[elindauer]

Nice point Tommy. Even after you play the million hands, the confidence interval calculation only tells you your win rate, but doesn't give any insight into what you are doing right or wrong. A simple hand review after a few thousand hands tells you all of this. Forget confidence intervals. Study the hands.

Good luck.
Eric

[skp]

[ QUOTE ]
I've never seen anyone bother to debunk it, so I'm going to try to do it now

[/ QUOTE ]

What you said sounds like good debunking to me. It also lends credence to the adage "if you can't spot the sucker in 15 minutes, you are it".

This may sound like I am tooting my own horn, but there was a time when I used to play B&M and a bunch of us were sitting around having dinner and discussing probable win rates. I had everyone's hourly win rate pegged down pretty tight. And this was just based on observation for a few months while playing part time. What I was probably doing was gauaging what I thought everyone should be winnning based on thier poker actions. The fact that their actual results matched my guesses (or so they said) was probably a bit fluky but I think it illustrates the point you were making.

Incidentally, on losing players, I never have any idea how much they should theoretically lose. To me, that's just impossible to gauge properly.

[Dreamer]

You don`t need 25 million hands to know if a player is any good.
I wrote a spreadsheet which you can download for free http://dreamer5.topcities.com/index5.html

With say 100K hands and a 2BB/100 winrate, There is a 99% chance that the true winrate is between +0.481 BB/100 and +3.519 BB/100.

Even after 100K hands it would be HIGHLY UNLIKELY that this player has no skill. (he is beating the rake also!)
And a high probability that his true winrate is much closer to 2BB/100.

You certainly do NOT need 25 million hands to tell if anyone is a winning player unless their play is extremely marginal.

D.

[pfkaok]

[ QUOTE ]
I honestly still haven't figured out what mistakes a so-called "weak-tight" player is making if he isn't playing tight-passive.

[/ QUOTE ]

Well, I would consider a weak-tight player to be somebody who is at least a little bit too passive, and also gives up on hands that he should at least take to showdown. His biggest mistake might be folding too much on the turn and river. Like maybe he always fold to turn raises unless he has an absolute monster or soemthing. Folding too much can be a huge mistake if you're playing against overly aggressive players, like many of the LAGs I've come accross at party 15/30. Also, it seems that even the tighter, solid players in that game make lots of bluff and semibluff raises, so if your main mistake in that game was folding too much then you'd have a very tough time beating that game.

Your suggestion for having somebody else to look over some hands to evaluate is a very good idea, and I think its probably the best way to find leaks... especially if you can't find any obvious leaks in your pokertracker stats.

[elindauer]

[ QUOTE ]
I honestly still haven't figured out what mistakes a so-called "weak-tight" player is making if he isn't playing tight-passive.

[ QUOTE ]
Well, I would consider a weak-tight player to be somebody who is at least a little bit too passive, and also gives up on hands that he should at least take to showdown.

[/ QUOTE ]

[/ QUOTE ]


So... a weak tight player is someone who's too tight and too passive? Sounds a lot like tight-passive to me.

I'd put forth the following definition: a "weak tight" player is somebody who plays tight and aggressive poker, but plays in an ABC way where you can peg his range of hands very easily. He isn't easy to play against by any means, but he'll never 3-bet you with 55, he'll never check-call-check-raise on a total steal, etc. As such, you can get slightly better reads and make a few more marginal folds against this player than you could against the perfect TAG. In most games with loose and passive opposition, the weak tight players looks just like the tough TAG. The differences only show up when these players face off with other tight players.

Of course, with this definition, "weak" is misleading.

-Eric

[kem]

[ QUOTE ]
Mike just dropped a monster post in which he says, to sum up, that limit poker is a joke because you have to play 25 million hands to know whether or not you're any good. He uses this argument to imply that the luck factor in limit hold 'em is very high.

I have now seen statements like this many times in many forms, and I've never seen anyone bother to debunk it, so I'm going to try to do it now. Here's the deal:

Let's say we look only at a player's results, and we attempt to determine if this player is a winning player. Fine. We check out his EV, we look at his standard dev, and we calculate a confidence interval. As Mike points out, correctly, we have to have a huge number of hands to determine somewhat conclusively that this player is a winner. Of course, this calculation uses no knowledge of poker whatsoever.

In real life though, we have much more information. Namely, we can look at the actual hands that were played, both by the player and by the opponents, to aid us in our estimate of how much money this player is making.

For example, if I see a player call 3 cold with A8, I don't need 2 million hands to tell me he's a losing player. I can do it in one. And if I'm playing with this guy, and he's losing money, then I'm winning it. Now I just look around the table, and look at all my opponents this way. If I can identify lots of obvious leaks, then I must be winning. It's that simple.

I've played about 30K hands of 15/30. Using confidence intervals, I can barely prove that I'm a break even player. But I know I'm a substantial winner. I know I'm not just on a two standard dev hot streak. I know this, because I ignore the mathematics of confidence intervals and use the much faster converging mathematics of poker. I know that calling 3 cold with A8 is making a hugely losing play, one that I don't make. I know that playing any 2 suited is a losing proposition. And I know a lot of things more subtle than that. I can see the poker mistakes that my opponents make, and I know that I am winning money from them.

This confidence interval stuff has been blown way out of proportion.

[/ QUOTE ]

It might be a stretch to go from "some players at my table are playing some hands sub-optimally" to "i'm a winning player".. you're missing a few important steps, like showing the money is going to you and not 1800gambler who's sitting to your left, and also quantifying their mistakes to the point where it overcomes the rake.

[pfkaok]

well, you might be right about the aggresssion part, but to me, I still think that the weak part means that he'll fold too much. I don't know if thats the accepted definition, but from descriptions I hear about "weak/tight" players thats what i've gathered.

[roy_miami]

[ QUOTE ]
I honestly still haven't figured out what mistakes a so-called "weak-tight" player is making if he isn't playing tight-passive

[/ QUOTE ]

You'll never know with any certainty when a player makes a weak-tight mistake as opposed to a loose passive mistake for instance.

Loose passive mistakes are often witnessed at showdown, like a guy catching a set of 2's vs a preflop raisor on a AKQ-5-2 board in a small pot.

The only time you'll have evidence of a weak-tight mistake is if a) you're the one who made it or b) he shows his AA before he mucks on a board of Q94-T to a raise.

I would guess the most common weak-tight mistakes are folding drawing hands when the pot is laying you proper odds to continue. For example, folding 99 on a 8JQ board in a big pot for 1 bet on the flop. This players thoughts would go along the lines of-- My 9 outs may be dead to QQ and my ten outs may be dead to AK so rather than risk hitting my card and still lose a bunch of bets, I'll just go ahead and fold now.

I'm sure most of us are guilty of making margional weak-tight mistakes (I know I am) but as with everything in poker, so long as you're making fewer and more margional mistakes than your opponents, you should come out ahead.

[helpmeout]

If only it was that simple, the reason why people make mistakes is because they dont know any better.

I might think I am a good player but a world class player may look at my game and see heaps of mistakes that I dont know about.

As Tommy says you may tilt more often than others or play tired not play your "A" game.

Your "A" game may not even be that good but you think it is because you read 2+2 and think that this somehow makes you a good player.

Common sense tells me whether I am at least a winning player after 50k to 100k hands.