## Sit-and-go calculations and edge

December 2, 2008 | 8:50 pm | Derk

When you play sit-and-gos, one of the key things to understand is the math behind your decisions. Even bad players have a general idea about what is good and what isn’t. Doing calculations using ICM and opponent modeling is an important way to verify your play and improve it. The remainder of this post is meant for people who are already familiar with ICM. If you’re not, check out the following:

Once you’ve got a good grasp of ICM, when you encounter a situation you should frequently be able to say “J8o?  I’d push this if it was suited, but since it’s offsuit I’ll fold” and be correct.  Being on the right or wrong side slightly is not a huge deal though.  I don’t get angry with myself if I shove in a -0.1% situation, or fold in a +0.1% situation.

One key thing to understand, though, is how much of an edge you need at different points in a SNG.  In a program like SNGWiz it sets the default edge higher when the stacks are larger relative to the blinds, and when there are more players left to act.  Here is a graph from their website:

So, even if you make a good decision that wins you 0.7% of the prize pool in the long run, doing so very early may be deemed incorrect by ICM calculators.  The reasons for the edge include:

• The high variance nature of making marginal plays
• Losing folding equity from players seeing you make a marginal play
• Future potential for better +EV situations
• The number of players and distribution of cards (see below)

Aside from just the pushing/calling ranges of your opponents, the stack sizes, and your cards, ICM calculators often need to be adjusted in the following ways:

• If you’re UTG and the blinds hit you next hand, you may need to make a slightly worse play than normal.  Say the edge needed is +0.2%, you may want to go ahead and make a +0.1% play.  I believe SNGWiz recently incorporated this into their program with “future game simulation” but I haven’t used it yet.
• Consider if it’s folded to you in the SB and you have a very marginal play.  You presume your opponent will call 20% making your shove barely +EV however this presumes that he’s equally likely to have any hand.  If it’s 9 handed and 7 players have folded you can bet that they didn’t fold good aces or high pocket pairs, slightly shifting the deck more towards the range they would call with — even more so if you are holding bad cards — thus turning marginally +EV situations into folds.  In this case, even SNGWiz doesn’t alter the edge.  9-handed SB shoving vs BB with everyone having 10 big blinds has the same edge as 2-handed SB shoving vs BB with 10 big blinds each.
• Calculations presume your opponents are all of equal skill.  In situations with very loose opponents, marginally +EV situations may be passed up, whereas with opponents who are better than you, marginally +EV situations may be needed to be taken more often.  This still doesn’t disregard the need for some edge at every point, just that it can be made smaller or larger.

Overall, the edge needed is a critical component.  You can analyze a hand in a vacuum and get the EV for that situation but by applying a minimum edge it allows you to look beyond the results of that hand and make better decisions for the long run.

Being aware of these factors that most people don’t usually think about will help you develop as a player and improve your sit-and-go game.

### 4 Responses to “Sit-and-go calculations and edge”

• December 3, 2008 at 2:46 pm

#### DonXris said:

That was a surprisingly succinct and easy to read ICM post.

Can I get a further explanation on the following statement:

“Losing folding equity from players seeing you make a marginal play”

I’m fairly sure I understand this point but could use a little further elaboration to make sure I am reading this correctly. Thanks Derk!

• December 3, 2008 at 3:07 pm

#### FDSaussure said:

@donXris: He means that when you make marginal plays with weak looking hole cards then other players may notice and loosen up their calling range against you. This means that a breakeven play may result in reducing your edge in other plays because of how the other players have adapted.

• December 3, 2008 at 4:13 pm

#### DonXris said:

Thus needing a larger edge after showing down a marginal hand. Ok I did get it.

• December 3, 2008 at 4:42 pm

#### Derk said:

Wow I didn’t even get here fast enough to reply to a comment Damn you LOTL. But yeah, it’s just like a cash game and image. When you play really loose in a cash game you have to switch gears and play tighter as your opponents adapt. The same thing goes for SNGs, most notably when you’re playing with a lot of regulars over and over again.