Variance

[PartyGirlUK]

There aer some very good posts in this thread. I guess you could say I belong to the 'aba' school of thinking. Imo people underestimate the impact of skill on swings.

Consider a marginal winner goes on a terrible run over 15k hands. He loses 500bb. He makes a couple of posts in BBV and they do indeed consider a number of sick, sick beats, hands where any good player would have lost the same amount. In fact, every single on of the bad beat hands was played perfectly by him. A number of experts chime in to say this. I think it might be easy for him to consider it proof that 500bb hands happen. Lets say he is .5bb long term winner. Someone else is 2bb/100. If the latter had gone on the same run of sick sick beats over 15k hands, he would 'only' be down 275bb.

Thinking about the 4 high profile limit posters that immediately spring to mind that went on long (>100k) breakeven or worse stretches, with the exception of JoshW they all play a ludicrous number of tables (6 to 8). I can't help but thinking that they were table selecting bad + playing too sessions in order to get unstuck. They also going to have a smaller edge playing that many tables. Someone 8 tabling at 1bb/100 is gonna make twice the hourly of someone 2 tabling at 2bb/100, but is gonna have way bigger downswings. Which isnt to criticise people who do this - I'm in awe of anyone able to play 6+ tables of sh limit successfully, but they will have longer (in terms of hands) breakeven stretches.

It's extremely difficult to play well when you are running really bad. Every single person Ive played lots with plays better when running well. Almost everyone I know plays more when stuck than after a nice score. I am more guilty than most of these sins. Because of this, I remain incredibly skeptical of claims such as 'I lost 450BB and played me A++ game throughout'. If the player in question wants to send me his hand histories for the stretch in question I would be happy to look through them btw. Also, I dont want people to think Im preaching/claiming to be superior. It's possible I've never been on a prolonged run of lack as bad as some of these guys, and if I did, my game may well go to bits without me knowing it.

I'm more risk averse than the clear majority of 2p2ers, and one really useful thing from this thread is that Im gonna keep focusing hard on game selection. For me, it's not worth playing in a game where my edge is only 1bb/100, even if I am super duper comfortably rolled for the level. Just too much variance, I hate losing for a long time, and the best way to avoid long breakeven stretches is to play in games where your edge is big. Maybe I'll just be content grinding it out at 30/60 and playing higher when the games are really juicy?

fsuplayer mentioned something about me running well in NL. I made a stat post in MSNL a month or so ago where I openly admitted this. I do stand by the statement that most people at 3/6 NL blow though. I also still believe that 2bb/100 is doable in the 100/200 stars limit game with minimal table selection, but Im definitely not good enough to achieve that rate.

[PartyGirlUK]

Should add, most of my work is based around analysing poker stuff in stata, so Im not totally clueless, and am aware that anything is possible. It *could* be that BK lost 1200bb while playing 1bb+/100 poker. It's possible. It's possible aba will go on a 60 buyin downswing while playing his A game. Anything is possible. But using bayes theorem leads me to the conclusions I make about how likely it is that most people who go on these massive downswings are deluding themselves.

Dean

[Hobbs.]

Dean,

Something I've been thinking a decent amount over the last couple of days is the idea that winrates in limit hold'em are normally distributed. I think it's pretty clear that winrate is not, but I'm stuck on how much this will have an effect on the things like bankroll requirements and downswing frequencies. I don't play nearly enough poker to have a large enough database to start looking at some of these things, but my best guess is that a lot of individual hands are going to have winrate distributions that have fairly fat tails. AA will likely have a fat tail on the negative side due to times you lose with it it is usually more than a couple of bbs, while 78s will a fat tail on the positive side (occasionally smash flushes, but fold early in hands otherwise). I'd further guess, but could be way off here, is that if ones winrate distribution has a fairly fat tail on the negative side the severity of downswings is likely going to be higher than common thought.

Anybody done any work on this or have any useful links?

[El Diablo]

Dean,

People who run better than average underestimate how much variance there is. People who run worse than average overestimate how much variance there is.

[PartyGirlUK]

Diablo that's a great (and true) aphorism.

[ggbman]

Dean, not going to really open this can of worms again, but what diablo said is pretty much correct. Also, pretty much every single limit and NL player i have talked to said that Aba's post in this thread is correct in the sense that having a positive attitude and focusing on your game as opposed to how you are running is correct, but understates how much variance can affect reults by a loooong shot.

Again seriously, i'm tired of saying this, BUUUT while you are correct that for most players, bad play and table selection etc... contribute to their downswings, but again, it is a mathamatical fact that some players will not make these erros and suffer huge downswings anyway. (Over 1000 BB at limit and maybe 25-30+ buyins at NL)

Just remember, the people who are the biggest winners in any game are NEVER running the worst or even below average on the whole. If they were, it would not be possible for them to be the biggest winners. Period. Sp while they could be the best players, they are also running the best, and their percpetion of how much their skill impacts their results will pretty much always be skewed. It's great to focus on your results and play and not how you run, but nieve to think that doing so will or should exempt you from some of the downswings discussed in this thread.

[DpR]

Does anyone have poker simulation software ? Get it cranking! Simulate 1000, 5M hand samples for a 1BB winner with 18BB SD (that should somewhat reasonably predict 1000 lifetimes of poker).

My guess is <5% would experience 1000BB downswings. Of course that means there are perhaps 50 who will.

[ggbman]

This was done earlier in the thread. Also, a SD of 18 BB/100 is only reasonable if you don't play HU or 3-4 handed a decent amount, which is not common if you play higher limits frequently.

[DpR]

[ QUOTE ]
This was done earlier in the thread. Also, a SD of 18 BB/100 is only reasonable if you don't play HU or 3-4 handed a decent amount, which is not common if you play higher limits frequently.

[/ QUOTE ]



This was NOT done earlier in the thread (this is not ROR).

Variance is not always equal among players, even though most here like to assume it is. I do NOT play HU or 2-3 handed (3 handed very occasionally), but in a exclusively 4-6 handed sample I have S.D results statistically 95% sure to be <17BB with a win rate 90% sure to be greater than 1BB ($30/50/100 - 25%/60/15).

These figures do not dispute what you are saying specifically, and high stakes gets higher and higher every month it seems (I guess $50 is mid-stakes now). I just think that variance is not as uncontrollable as many like to think it is (i.e. can be controlled more than given credit for w/o a reduction in win rate).

Also, I do not disagee with the general position you have presented in this thread. Although, I do think you (and Dean) have exagerrated both sides a touch (in opposite directions). The people with a real undertanding of statistics can take these statistical figures and meaningfully interpret them for practical use. Most people however have a very weak understanding and want the figures to tell them something concrete and certain - which statistics will never do.

IMO, the bottom line is, given a large winning player not playing <4 handed, I would not expect that player to ever go on a 1000BB downswing. Given a large group of such players, there were certainly be several that do experience it. Now, people just need to decide if they want to plan to be unlucky in the bankroll management or not.

I would just say that I do not believe that a significantly winning high (or med high) stakes player (not playing super short) should expect, or even be somewhat likely, to have a 1000BB downswing over a million hand sample (I would not include <1BB/100 winners in this statement, which is perhaps where some of the disagreements come from since games are shorter and win rates lower the higher you go, so me talking about 50/100 vs you talking about 200/400 can lead to many misunderstandings - and your points in this thread are precisely the reason I do not play 2/4 online).

[Abbaddabba]

I dont see how a small winner (0.5BB/100 or less) with a standard deviation of 25+ can really even KNOW that they're winners.

And yet at the same time, it seems unfathomable that anyone is a really big winner at those games. 2BB/100 at 200/400 3 or 4 handed seems absurd, unless you are extremely selective about who you play (ie: wait for nemo). Is that a fair statement?