My true ROI is ... (very low content)

[gasgod]

We see this statement so often on this forum, and I don't understand why so many people think it's a meaningful statement (or question).

The phrase "true ROI" presupposes two things, both of which are false.

First, it assumes that your game is static; you are neither improving nor getting worse. But the very fact that you post here is evidence that you are trying to improve.

Second, it assumes that the skill level of your average opponent is static. But the poker landscape is a work in progress. As long as the number of players is growing, the average skill level is probably going down. If the number of players reaches a plateau, then I'd guess the average skill level will start to go up. If the poker population starts to shrink, watch out. It's probably not the winners that are quitting.

Bottom line: You don't have a 'true ROI'. Your ROI at this moment is a function of your skill level compared to the skill level of your opponents. Both of these are changing, and by the time you play enough games to be statistically significant, the landscape will probably have changed significantly.

GG

[dfscott]

I agree 100%. I hate the posts saying "after you've played 1000 SNGs, you should have a good idea what your ROI is." Well, I've played almost 1000 SNGs and if my overall ROI of 6.2% is a true indication of my "real" ROI, I'd be done with SnGs. As it is, I'm certain that a lot of my stats are the result of poor play while I was learning (not to imply that I'm not learning now, but I think the early leaks are much more costly than the ones I have now).

This is why once I get 1000 SnGs (which I'm shooting to get by the end of the month), I'm going to wipe all my stats and start over. Not only do I think it'll be a more accurate respresentation of my playing abilities, I think it'll help my confidence as well.

[skipperbob]

As a prelude to the WSOP, Irieguy & McPherzen played 1000 $109 SnG's...They produced a 6% R.O.I.....I think they are as good as it gets; therefore 6% ROI may be the "real deal" [img]/images/graemlins/frown.gif[/img]

[gumpzilla]

[ QUOTE ]
As a prelude to the WSOP, Irieguy & McPherzen played 1000 $109 SnG's...They produced a 6% R.O.I.....I think they are as good as it gets; therefore 6% ROI may be the "real deal" [img]/images/graemlins/frown.gif[/img]

[/ QUOTE ]

Presumably it's a different story at the 33/55s, where I believe dfscott is playing these days.

Also, while it's a bit early to be conclusive, it looks like ZeeJustin is probably well on his way to a >6% ROI over 1000 games in the 215s.

[pooh74]

This has been discussed to death...(not to say it is worthless to still talk about).

Its like arguing about God or abortion...no one is changing their minds around here on this issue...but I agree with OP and scott...true ROI is meaningless. I have stopped keeping stats actually and just enjoy the extra income...my true ROI is fun+$.

[eastbay]

[ QUOTE ]
We see this statement so often on this forum, and I don't understand why so many people think it's a meaningful statement (or question).

The phrase "true ROI" presupposes two things, both of which are false.

First, it assumes that your game is static.

Second, it assumes that the skill level of your average opponent is static.

[/ QUOTE ]

I think this old "debate" is boring, and I think your objections are mostly academic and miss the point of what most "true ROI" discussions are getting at.

ROI has an expectation value. This is generally what people are referring to as "true ROI." This has a well-defined meaning.

How well you can "measure" the expectation value is open to some speculation. Maybe you will improve, maybe the player pool will improve. Then again, maybe neither will happen fast enough that an active player can get a sample over which the game conditions are effectively stationary. Do you really think ZeeJustin's game is going to change that much over the next 1k SnGs he's going to play this week, or do you really think the player pool is going to evolve in that week's time? No way. Those are infinitesimal deltas over that time frame. The stationarity assumption is a good one in that case, so sample size estimates based on a stationarity assumption are useful.

Now if you're talking about someone who started playing three months ago and they play 5 SnGs a week, yes, there is major non-stationarity in what he is trying to measure and him trying to measure his "true ROI" is silly. There's no way he can do it before it will move on him significantly.

Now, returning to what I think is the main problem with your objection is that estimates of sample sizes needed for knowing "true ROI" are generally used to support the position that a sample isn't high enough to draw a conclusion. The stationarity assumption that goes into those required sample sizes only makes them more optimistic than they would be for a non-stationary system. So the point remains. Non-stationarity only lengthens the sample needed to get an idea of expected ROI.

Bottom line: You do have a "true ROI" and anybody who thinks differently is wrong. However, it may not be possible to measure it, depending on how active you are, and how dynamic both your game and the player pool are. But we knew that was really hard to do in any case.

eastbay

[mosdef]

as usual, the "debate" itself usually boils down to the wide variety of different used of various words on the forum, and as a result both sides of the debate are right because both sides are talking about two different things.

it also has a lot to do with the questions people choose to ask about their data. For example, you can play, let's say, 1000 tournaments and observe an specific ROI over those tournaments. This is really just one outcome for a random variable that had a large range of possible outcomes. there are two questions you can ask.

1. what does this mean with regard to my expected ROI (actual ROI, if you will) over my next set of tournaments. this is subject to the non-constants mentioned by the OP (i.e. developing skill and non-static opponent pool)

2. what does this say about my expected actual ROI (expected ROI) over the 1000 tournaments that i just played? the ROI random variable over those tournaments just played is what it is, and is not subject to the variations in skill and opponent pool that worry the OP.

anyway, for the umpteenth time, failure to precisely define terms and scenarios so that there is no doubt about what you're talking about is what causes the debates; after both sides have interpretted a statement their own way, they can both be right.

[Slim Pickens]

The people who seek their "true ROI" as though it was some sort of statistical sacred artifact are probably the same people who go rabbit hunting. Look, the river card does not exist until it is turned face up. If everyone folds, the river card never existed. You can try to measure it, but all you are doing is collapsing the probability distribution to a single point. If you measured it again under the exact same conditions, you'd be measuring from the same probability distribution, but by no means assured the same answer for any subsequent measurement.

Try to measure your ROI and you'll get an answer. Try to measure it again and you'll get a different answer. They all come from the same probability distribution. We can say a lot about it based on the stochasitic nature of poker, but there's a lot of external factors we can't measure that influence the distribution as well. It all converges to an expected value, but it will never converge to a line, nor even a normal distribution determined by the internal statistics of poker.

Meh. I'm sick of this. I should have deleted the ROI cells on the spreadsheet and just left the bankroll plot.

SlimP

[the shadow]

[ QUOTE ]
Now if you're talking about someone who started playing three months ago and they play 5 SnGs a week, yes, there is major non-stationarity in what he is trying to measure and him trying to measure his "true ROI" is silly. There's no way he can do it before it will move on him significantly.


[/ QUOTE ]

Good point. Even though "true" ROI can move quickly, observed ROI sets a lower bound for "true" ROI for an improving player, just as it sets a upper bound for "true" ROI for a player to moves to higher SNGs. Both applications can be useful.

The Shadow