# Ready To Move Up Levels? SNG Sample Size, Confidence Intervals and ROI

Personally I have lost count of the number of poker forum posts that start along the lines of; "I have an ROI of 54% in \$15+1 SNGs over 130 games should I move up?". While there is nothing wrong with asking this type of question it does highlight some common misunderstandings about the nature of both Bankroll Management and ROI (return on investment) Potential in Sit and Goes.

This article looks at the question of how confident a player can be that their current profit margins are a result of skill and not the natural swings in the game. It is designed to compliment our article which looks at the Difference Between Buy-In Levels In SNG Tournaments in terms of the opponents you will face.

### How Many SNGs Make A Good Sample Size For Determining Your True Return On Investment

Let us start with the SNG sample size question. As discussed in this article introducing ROI for SNGs there is a danger in inferring success (or otherwise) from a small sample of SNGs.

The question is what kind of sample size do you need to have a good feel for your 'true' Return on Investment at any given level. Fortunately the math behind this has been done for us - by that same group of SNG Pros from 2+2 who came up with the original ROI expectations chart.

The chart below shows the statistical likelihood of a given sample of SNGs being a true indication of your ROI, these numbers are known as 'confidence intervals' as they show how confident we can be about each sample being a 'true' reflection.

100 games: ~23%

300 games: ~40%

1000 games: ~66%

2000 games: ~82%

What this tells us is that a 100 SNG sample only has a 23% chance of being an accurate reflection of your ability. The fact that running your Kings into Aces just once at the bubble can have a large effect on your ROI should make this easy to understand. What is more suprising for me is the fact that even a 2000 game sample would only be 82% accurate. If nothing else this should give us food for thought about managing our SNG bankrolls properly.

1. Do I have a large enough bankroll to withstand variance at the next level? (50 buy-ins being the rule of thumb)
2. Am I disciplined enough to move back down should the initial results go against me??

Question 2 is critical to advising anyone to move up SNG Levels - winning in SNGs, as with all poker - requires not only skills at the table but good bankroll management, patience and discipline.

### Planet Mark’s Rec:The Easiest Sit and Goes Online are Over at America’s Cardroom!

You can use them to grow a bankroll, qualify for online tournaments, or even to help you win a seat in the World Series.

Instead of tables full of ‘regulars’ who know the math, bubble strategy and hand ranges, ACR Poker is recreational. Compare the fields to the bigger sites, and you will quickly see how soft they are for yourself.

You can get your bankroll off to a flying start with a 100% matched bonus using referral code: SNGPLANET

Check out the latest promos and tournament events for yourself now, over at www.americascardroom.eu!