Discussion hand 4: Bubble microstack

    • pzhon
      pzhon
      Bronze
      Joined: 17.06.2010 Posts: 1,151
      Here is another hand for discussion. Again, the goal is not to get the right answer, but to think about some interesting situations. Please feel free to post some ideas even if you might change your mind later.

      Medium stakes 50-30-20 SNG bubble, blinds 250/500

      CO (unknown): 4724
      BTN (seems conservative): 5752
      SB (unknown): 2446
      BB (dominant reg): 578, 78 chips after posting

      Note the very short stack in the big blind. The BTN has not been pushing aggressively despite his chip lead. The big blind is at the top of the SharkScope leader board for this level, and should be assumed to be an expert.

      Preflop:
      CO folds, BTN pushes 5752, SB calls 2196, BB folds.

      Questions:
      1) What range do you give the BTN for pushing?
      2) What range do you give the SB for calling in practice?
      3) With what range should the big blind overcall?
      4) How much equity does the small blind need against the BTN's range to call?
      5) Given your answers to 1 and 4, with what range should the SB call?
  • 8 replies
    • elhh82
      elhh82
      Bronze
      Joined: 03.09.2008 Posts: 6,838
      1. Even given that he is conservative, and that he most likely doesn't want to double up the BB with crap, he should push at least all pairs, Ax, broadways, most suited kings and the higher suited queens.

      I'd say anyway between 25-30%

      2. In practice, i think many (bad) unknowns will find it hard to fold their top 5%. Which is AQ+,99+. And i guess they will often assume the BB always calls too.

      3. KK+

      4. Something like 76% according to ICM Explorer

      5. QQ+
    • chenny8888
      chenny8888
      Bronze
      Joined: 03.10.2007 Posts: 19,324
      if SB's range is KK+, BB should only call AA ;) .
    • pzhon
      pzhon
      Bronze
      Joined: 17.06.2010 Posts: 1,151
      In this situation, I think there is a large difference between what people will actually do in the small blind and what they should do. In part, some players will assume that the big blind has to overcall due to pot odds, when in fact that would be a huge mistake with most hands. So, question 3 was which hands the big blind should play in practice, against typical imperfect opponents.
    • elhh82
      elhh82
      Bronze
      Joined: 03.09.2008 Posts: 6,838
      I think in this particular spot, not too many will make the "huge" mistake of calling with the raggier aces or the lower pairs, although calling with AQ/AK is in itself a big mistake.

      It's just too obvious that they have to fold here
    • elhh82
      elhh82
      Bronze
      Joined: 03.09.2008 Posts: 6,838
      I guess i should revise my analysis after this hand at the $6.50. Although you did say midstakes

      Grabbed by Holdem Manager
      NL Holdem $500(BB) Replayer
      SB ($4,141)
      BB ($1,300)
      Hero ($5,590)
      BTN ($2,469)

      Dealt to Hero Q:club: Q:spade:

      Hero raises to $5,590 (AI), fold, SB calls $3,891 (AI), fold

      FLOP ($8,782) 4:spade: 8:heart: 7:diamond:

      TURN ($8,782) 4:spade: 8:heart: 7:diamond: 4:club:

      RIVER ($8,782) 4:spade: 8:heart: 7:diamond: 4:club: 6:club:

      SB shows T:diamond: A:club:
      (Pre 29%, Flop 16.8%, Turn 6.8%)

      Hero shows Q:club: Q:spade:
      (Pre 71%, Flop 83.2%, Turn 93.2%)

      Hero wins $8,782

      Villain should know that i'm not pushing ATC here, i would have pushed ATC in the previous hand. I'm not here because i have no FEQ against the BB. I was however abusing the bubble pretty hard in this game.
    • hacacare
      hacacare
      Bronze
      Joined: 01.04.2009 Posts: 2,939
      1) What range do you give the BTN for pushing?

      Button should probably not push wider than 50%. If I am not wrong, the model based on ICM never suggests moves that cause loss in chips (or at least you told that once if I am not wrong). Since he has practically no fold equity on BB, he shouldn't push wider.

      2) What range do you give the SB for calling in practice?

      He should call only with KK+, but in practice there are some calls with hands like AK, JJ
      (Nash suggests JJ+ with 38% BU pushing range, but ICMExplorer says SB needs 75,6% equity to call? )

      3) With what range should the big blind overcall?

      aces

      4) How much equity does the small blind need against the BTN's range to call?

      75,6%

      5) Given your answers to 1 and 4, with what range should the SB call?

      KK+
    • pzhon
      pzhon
      Bronze
      Joined: 17.06.2010 Posts: 1,151
      Originally posted by elhh82
      Villain should know that i'm not pushing ATC here... I'm not here because i have no FEQ against the BB.
      Originally posted by hacacare
      the model based on ICM never suggests moves that cause loss in chips
      This is a very important observation to make. I see some calls which would be wrong against an ATC range, but also many calls which would only make sense if you put the big stack on ATC, which should not be the case here.

      The BTN is slightly risk-averse, and should pass up on some pushes with hands which would gain chips. Note that because the SB should rarely call, the 250 chip small blind is almost dead money, so pushing with less than 50% equity against a random hand may gain a few chips. However, in the Nash equilibrium, the BTN pushes only hands which have at least about 53.5% equity against a random hand.
    • pzhon
      pzhon
      Bronze
      Joined: 17.06.2010 Posts: 1,151
      Originally posted by elhh82
      4. Something like 76% according to ICM Explorer
      ICM Explorer was not designed to handle multiway situations. ICM Explorer assumes that the BB will never overcall, which is close enough to correct with expert play from the big blind. However, ICM Explorer also assumes that if the SB folds, then the BB will fold. However, if the SB folds, the BB will call.

      If the BB's calls hurts the SB, then ICM Explorer will overvalue folding, and will say that the SB needs too much equity to call. If the BB's calls help the SB, the reverse happens.

      In most SNG situations, you want to see your opponents collide. This is an exception, at least according to the ICM. The ICM says that if the BB folds and is crippled to 78 chips, this is almost as good for the SB as if the BB is eliminated. Since the SB would strongly prefer to see the BB eliminated over seeing the BB double up, it is bad for the SB that the BB will call, and this means the SB does not need as much equity to call as ICM Explorer says.

      In SNG Wizard, if you expand the winner in Analysis Details, you can get the ICM estimates for the outcomes, and SNG Wizard also reports the equity for folding. If you give the BTN a 30% range, then folding averages about 24.81% of the prize pool. Losing (with no overcall) is worth 0%. Calling and winning (with no overcall) is worth 35.3%. So, it appears that the SB only needs about 24.81/35.3 = 70.3% equity against the BTN's range to call. Against a top 30% range, QQ would be a close decision and JJ would be a clear fold. Against a top 50% range, JJ would have enough equity to call.

      In the actual hand, the SB called with a good hand which didn't have close to enough equity even against a random hand, which we have seen would not make sense for the BTN.