HU play: nash vs sng wizard

    • outspan
      outspan
      Bronze
      Joined: 07.02.2010 Posts: 1,196
      Hey all!

      I just made gold status so I'm browsing around the new articles and vids :) .
      I use SNG wizard, and I noticed that the program wants me to push looser than Nash in a HU situation - almost any two with around 12-13bb. Isn't that too loose? And also, should I set the edge in sng wiz to 0 at all times?

      thanks!
  • 7 replies
    • pzhon
      pzhon
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      Joined: 17.06.2010 Posts: 1,151
      You should have a specific reason any time you set the edge to something nonzero. One particular reason might be that you want to account for the cost of hitting the blinds next hand, which means folding is overvalued by the ICM (and so is doubling up, but not proportionally).

      Whenever you use SNG Wizard, you must consider adjusting the default ranges. SNG Wizard's default ranges are very far from accurate, and if you don't adjust them to something more reasonable then the recommendations may damage your game and cost you money. SNG Wizard often assumes that players will push and call way too tightly in blind-versus-blind situations. This means SNG Wizard recommends calling very tightly, and pushing ATC against an opponent who matches the default ranges. Enter your estimates of your opponents' ranges instead.
    • shAdOwArt
      shAdOwArt
      Bronze
      Joined: 14.07.2009 Posts: 363
      Beware of push/fold strategies while in the final two against a somewhat aware opponents. Every single push/fold strategy has a negative expected value against the Nash calling range while the effective stack is above 8bb. Professional HuSnG players use a lot of minraises at these stack depths, both against fish and against each other.
    • pzhon
      pzhon
      Bronze
      Joined: 17.06.2010 Posts: 1,151
      I disagree with the idea that a push/fold strategy is wrong just because it loses chips. When you are heads up, the BB acts second preflop. This means the BB has position preflop. When the stacks are large enough, this positional disadvantage preflop outweighs the advantage of posting a smaller blind, so the SB loses chips. However, this doesn't mean you will do better by making a small raise which comes close to committing you. If the effective stack depth is 8 bb, the BB can reraise with a few more hands he would call an 8bb push, and that means he doesn't have a positional disadvantage postflop. That pushing range is so wide that it doesn't gain much if anything to raise/fold, so in theory minraising can't be much better than playing push/fold at 8bb. Minraising can't gain many chips in theory. It could be ok as an exploitive strategy.

      It is natural to make a small raise, perhaps a minimum raise, when the stacks are about 12-20 bb. This small raise does not leave you committed for 12 bb, and many players will not push often and will defend some of the time by calling, granting you a positional advantage postflop. Because postflop matters, you might also adopt a strategy which pushes some hands, makes a small raise with some, and which folds some of the time. You might tend to push hands which are harder to play postflop in case you get called, but which have decent hot and cold equity. Even if you simply minraise if you raise, this should be better than playing push/fold when the stacks are over 12 bb.
    • VBZg
      VBZg
      Bronze
      Joined: 06.12.2009 Posts: 572
      Originally posted by pzhon
      One particular reason might be that you want to account for the cost of hitting the blinds next hand, which means folding is overvalued by the ICM (and so is doubling up, but not proportionally).
      Where can i find video/post on disadvantage's of sngwiz and how to adjust? Or what are the most often situations to take into account of shortcomings of sngwiz? Thx
    • pzhon
      pzhon
      Bronze
      Joined: 17.06.2010 Posts: 1,151
      The biggest shortcomings of SNG Wizard are not related to what you quoted, the cost of hitting the blinds next hand. That's a very small issue. The biggest issue is that SNG Wizard does not have a good opponent model, so its default ranges are unrealistic which makes both the automatic analysis of entire tournaments (or the parts where you have up to 10 bb) and the quizzes close to useless.

      SNG Wizard only lets you play push/fold, and it assumes that after you act, your opponents will play push/fold. So, it is very hard to analyze whether to call a resteal using SNG Wizard, even though this is a simple ICM calculation. Use my program ICM Explorer for that. You also can't model getting flat-called, which is common if you push with a very short stack while your opponents have large stacks.

      A more minor issue is that SNG Wizard uses the Sklansky-Chubukov hand ranking, which overvalues hands which are ahead in 2-card poker. This is not so bad for calling, but it leads to strange pushing ranges. I push 76s in many situations where J6o is not a push, but in order to put 76s in a pushing range you have to include even worse hands like J4o.

      Another minor issue is that SNG Wizard assumes there are no ties. If you have AKo and run into AKo, SNG Wizard assumes that you lose 50% of the time instead of splitting the pot about 95% of the time. This can make a significant difference if you are considering calling with Ax while you are risk-averse, since Ax often ties against other Ax hands even if the kickers are not equal. It doesn't make much of a difference if you are considering calling with a pair.

      Nevertheless, the main shortcoming is that you constantly have to do a lot of work setting ranges for your opponents, sometimes including the overcalls or the pushes and calls after you fold. So it is very hard to analyze some early position pushes because you have to make many assumptions for others' ranges, perhaps coming up with push/fold ranges which are somehow equivalent to the way your opponents play when they do not play push/fold.
    • VBZg
      VBZg
      Bronze
      Joined: 06.12.2009 Posts: 572
      Thx a lot Pzhon. Just one more thing, what about bubble and when blinds get high, as for example when all players are below 10bb, what about then, should we take some considirations about sngwiz calculation (shortcomings)?
    • pzhon
      pzhon
      Bronze
      Joined: 17.06.2010 Posts: 1,151
      You still have to enter ranges for your opponents since the default ranges are often bad. You might want to analyze the cost of hitting the blinds, and use a slightly negative edge when you are UTG according to the analysis, and perhaps a slightly positive edge when you are in the SB to make up for the free hands you will miss if you get knocked out.