Two Plus Two Poker Forums SNGs: Confused why the caller of a shove must ALWAYS have a tighter range than the shover
 Register FAQ Search Today's Posts Mark Forums Read Video Directory TwoPlusTwo.com

 Notices

 STT Strategy Discussion about the play of single table tournaments.

 07-03-2017, 06:58 AM #1 bdc enthusiast   Join Date: Aug 2008 Posts: 60 SNGs: Confused why the caller of a shove must ALWAYS have a tighter range than the shover I thought I knew ICM quite well, having read all of Moshman, Shaw & "Kill Everyone". If all players have equal stacks then the Bubble Factor is identical for each of two players engaged in an all-in. The same for two identical stacked players going all-in when the other stacks have differing stack sizes (but both all-in players need >> 50% breakeven-equity due to ICM leakage to the other players). BUT these books imply in ALL cases the caller must play much tighter than the shover even when they both have equal stacks. Are the books utilizing the Gap Concept and Fold equity to require the caller to play much tighter than the shover when the two all-in participants have equal stacks? (but this has nothing to do with ICM) The exact same question for short-stack 'GTO Equilibrium Play'. I quess I'm missing something very fundamental. Can anyone clarify this? Thanks.
 07-03-2017, 07:32 AM #2 Gamblino newbie   Join Date: May 2017 Posts: 36 Re: SNGs: Confused why the caller of a shove must ALWAYS have a tighter range than the shover Not sure if I can explain this correctly, this are just my thoughts about it: In very simple words: Lets say opponent shoves 50%. You call with 50%. So about half of the time you will be ahead, and half of the time you will not be ahead. The propability of being behind with the bottom of your range like T8o is very high. So you exclude this hand from your calling range. You keep doing this with every possible hand vs the 50% range. You exclude every hand that has below 50% equity. After doing so, you got your smaller calling range. If the opponent shoves 50% of all possible hands, the worst hands go out of the range. Now only 50% is left. Your new range now goes with 50% best hands OUT OF THE 50% that are left to be breakeven. I know the numbers are not perfectly correct. Gesendet von meinem ONE A2003 mit Tapatalk
 07-03-2017, 09:07 AM #3 Zamadhi centurion     Join Date: Jun 2017 Location: halloween Posts: 198 Re: SNGs: Confused why the caller of a shove must ALWAYS have a tighter range than the shover Example: * Prize pool: \$100 * Prize structure: 50/30/20 * Players left: 4 * Everyone has a stacksize of 2500 Everyones ICM is now \$25 (\$100/4) If I call an all-in and win I will eliminate a player, burst the bubble and double my stack. According to icmcalculator the ICM EV is now: \$38,33 for me and the other two remaining players' stacks have a \$30,83 ICM EV each. If I lose the all-in my ICM is \$0 and I am eliminated. Notice that the other two players gained \$5,83 ICM EV without having to risk a single chip! So I risk \$25 to gain \$13,33. \$25/\$38,33 = I must be a 65% favorite to call the all-in. The other player can push relatively wide on the bubble because he knows I must call relatively tight. Even if I hold AT and he moves all-in and show me KQ I should fold in this simplified example. Having the best hand is not enough! Why? Because the chips one gains are not worth as much as the chips one lose. Of course, the reality of blinds and ante make it so we should call wider, depending on how big those blinds and antes are. Last edited by Zamadhi; 07-03-2017 at 09:19 AM.
 07-03-2017, 10:15 AM #4 recondite7 old hand   Join Date: Jul 2005 Location: Austin Texas Posts: 1,875 Re: SNGs: Confused why the caller of a shove must ALWAYS have a tighter range than the shover When you call an all in you are guaranteed to have to go to showdown. In a cash game this is simple decision because your edge needs to be anything with positive chip equity. In a sng, icm requires that this edge be much greater so a caller will adjust his range to be very tight. This can be dramatically different. The person who is considering shoving knows that anyone he shoves into should be tight and can therefore shove very wide because he is unlikely to see a showdown. Even if a caller knows that he is being shoved on with 100% of hands, there is no way to profitably exploit this as a caller in many instances. Remember that in sngs there are many situations where both the shove and the call can be negative \$ev. The players who are not in the hand are the ones that gain the \$ev.
 07-03-2017, 08:01 PM #5 danielj centurion   Join Date: Nov 2012 Posts: 141 Re: SNGs: Confused why the caller of a shove must ALWAYS have a tighter range than the shover It's not always tighter, for example blind vs blind 3BB can have 70-80% range for SB and any two for BB. The EV of shoving takes into account how often you pick up the dead money, how often your opponents will call, and what equity you have against their calling range. As a caller it's most important to have good enough equity. Some other factors such as how much players behind will overcall etc at play too. All of this is true with or without ICM. With ICM you'll just have a more complex situation with more factors at play.
07-03-2017, 08:27 PM   #6
jukofyork
Carpal \'Tunnel

Join Date: Sep 2004
Location: Glastonbury Grove
Posts: 11,275
Re: SNGs: Confused why the caller of a shove must ALWAYS have a tighter range than the shover

Quote:
 Originally Posted by bdc BUT these books imply in ALL cases the caller must play much tighter than the shover even when they both have equal stacks. Are the books utilizing the Gap Concept and Fold equity to require the caller to play much tighter than the shover when the two all-in participants have equal stacks? (but this has nothing to do with ICM) The exact same question for short-stack 'GTO Equilibrium Play'. I quess I'm missing something very fundamental. Can anyone clarify this? Thanks.
Long time since I've thought about poker so hopefully this makes sense

Consider this simple game:

Two players get dealt a real value between 0 and 1.

Player 1 shoves all-in with Q% of his range.

Player 2 can now either fold (and win/lose nothing) or call, in which case he wins \$1 if his value is greater than player 1's, else he loses \$1 if his value is less than player 1's.

What range, P%, should player 2 call with?

With the help of wolfram alpha, here's the solution:

Player 1's range: "UniformDistribution[{1-p, 1}]".
Player 2's range: "UniformDistribution[{1-q, 1}]".

PDF[UniformDistribution[{1-p, 1}], x] = 1/p
CDF[UniformDistribution[{1-q, 1}], x] = (q+x-1)/q

P(player 1 wins) = Integrate[PDF[UniformDistribution[{1-p, 1}], x] * CDF[UniformDistribution[{1-q, 1}], x], {x, 1-p, 1}] = Integrate[1/p * (q+x-1)/q, {x, 1-p, 1}] = 1-p/(2*q)

EV = p * ( P(player 1 wins)*(+1) + (1-P(player 1 wins))*(-1) ) + (1-p) * (0) = p*(P(player 1 wins)*1 - (1-P(player 1 wins)) = p*((1-p/(2 q))-(1-(1-p/(2 q)))) = p*(1-p/q)

So now to find the p that maximizes EV:

d/dp p*(1-p/q) = 1-(2*p)/q

1-(2*p)/q=0 ---> p=q/2

So player 2 maximizes his EV when he calls with exactly half the range player 1 shoves with - this is Sklansky's "Gap Concept".

--------------------

If you want then you can quite easily change the EV formula above to account for blinds or ICM equities.

If you don't get how this works then try redoing the steps with player 1 shoving 100% of his range... You should see then that the EV formula is a balancing act between how much you fold and how good a hand you have when you call; with the two extremes being folding every hand and calling every hand (both of which are obviously 0EV)... It turns out that your EV is maximized when 50% of the time you fold and 50% of the time you call (and win 75% of the times you call). You can see it's 75% of the time without any need for the PDF/CDF integral too: 50% of the time player 1 will have a worse hand than player 2 (and lose 100% of the time), and the other 50% of the time it will be a coinflip (and player 2 will lose 50% of the time).

Juk

Last edited by jukofyork; 07-03-2017 at 08:44 PM.

 07-03-2017, 11:13 PM #7 bdc enthusiast   Join Date: Aug 2008 Posts: 60 Re: SNGs: Confused why the caller of a shove must ALWAYS have a tighter range than the shover Thanks for the replies. jukofyork I understand your great explanation. I already had a gut feeling that the "Gap Concept" was not explicitly integrated with the ICM discussion in all three books (to simplify things), but it's a big omission. I think this is also omitted from "GTO Equilubrium Play (Shove & Call Charts)". I guess I should have bought Chen & Ankenman's book for some rigour (I'm a mathematicion too).
 07-04-2017, 11:20 AM #8 LeaksSuck old hand     Join Date: Sep 2012 Posts: 1,838 Re: SNGs: Confused why the caller of a shove must ALWAYS have a tighter range than the shover No need to be confused cause it's not true
 07-05-2017, 02:17 PM #9 Rusemandingo Carpal \'Tunnel     Join Date: Oct 2008 Location: Playas de Rosarito Posts: 13,994 Re: SNGs: Confused why the caller of a shove must ALWAYS have a tighter range than the shover Yeah if pot odds overcome ICM tax, caller can be on wider range than shover.
 07-06-2017, 06:40 AM #10 LeaksSuck old hand     Join Date: Sep 2012 Posts: 1,838 Re: SNGs: Confused why the caller of a shove must ALWAYS have a tighter range than the shover And there are games where this isn't even a necessary condition. E.G. if u have a much bigger stack than your opponent(s) in a game with high relative bounty value, your opt. calling range might be bigger than jammers range at all of his stack depth. Most of this is common sense combined with a feeling for how ICM/FGS works in certain spots. Some results look pretty counterintuitive at first glance tho, try overcalling spots in high rel. bounty games

 Thread Tools Display Modes Linear Mode

 Posting Rules You may not post new threads You may not post replies You may not post attachments You may not edit your posts BB code is On Smilies are On [IMG] code is On HTML code is Off Forum Rules
 Forum Jump User Control Panel Private Messages Subscriptions Who's Online Search Forums Forums Home Links to Popular Forums     News, Views, and Gossip     Beginners Questions     Marketplace & Staking     Casino & Cardroom Poker     Internet Poker     NL Strategy Forums     Poker Goals & Challenges     Las Vegas Lifestyle     Sporting Events     Politics     Other Other Topics Two Plus Two     About the Forums     Two Plus Two Magazine Forum     The Two Plus Two Bonus Program     Two Plus Two Pokercast     The Best of Two Plus Two Marketplace & Staking     Commercial Marketplace     General Marketplace     Staking - Offering Stakes     Staking         Staking - Offering Stakes         Staking - Seeking Stakes         Staking - Selling Shares - Online         Staking - Selling Shares - Live         Staking Rails         Transaction Feedback & Disputes     Transaction Feedback & Disputes Coaching & Training     Coaching Advice     Cash Game Poker Coach Listings     Tournament/SNG Poker Coach Listings Poker News & Discussion     News, Views, and Gossip     Poker Goals & Challenges     Poker Beats, Brags, and Variance     That's What She Said!     Poker Legislation & PPA Discussion hosted by Rich Muny     Twitch - Watch and Discuss Live Online Poker     Televised Poker     Two Plus Two Videos General Poker Strategy     Beginners Questions     Books and Publications     Poker Tells/Behavior, hosted by: Zachary Elwood     Poker Theory     Psychology No Limit Hold'em Strategy     Medium-High Stakes PL/NL     Micro-Small Stakes PL/NL     Medium-High Stakes Full Ring     Micro-Small Stakes Full Ring     Heads Up NL     Live Low-stakes NL Limit Texas Hold'em Strategy     Mid-High Stakes Limit     Micro-Small Stakes Limit Tournament Poker Strategy     STT Strategy     Heads Up SNG and Spin and Gos     Mid-High Stakes MTT     Small Stakes MTT     MTT Community     Tournament Events Other Poker Strategy     High Stakes PL Omaha     Small Stakes PL Omaha     Omaha/8     Stud     Draw and Other Poker Live Poker     Casino & Cardroom Poker         Venues & Communities         Regional Communities     Venues & Communities     Tournament Events         WPT.com     Home Poker     Cash Strategy     Tournament Strategy Internet Poker     Internet Poker         Winning Poker Network         nj.partypoker.com         Global Poker     Commercial Software     Software         Commercial Software         Free Software General Gambling     Backgammon Forum hosted by Bill Robertie.     Probability     Sports Betting     Other Gambling Games 2+2 Communities     Other Other Topics         OOTV         Game of Thrones     The Lounge: Discussion+Review     EDF     Las Vegas Lifestyle     BBV4Life         omg omg omg     House of Blogs Sports and Games     Sporting Events         Single-Team Season Threads         Fantasy Sports     Fantasy Sports         Sporting Events     Wrestling     Golf     Chess and Other Board Games     Video Games         League of Legends         Hearthstone     Puzzles and Other Games Other Topics     Politics     History     Business, Finance, and Investing     Science, Math, and Philosophy     Religion, God, and Theology     Travel     Health and Fitness     Laughs or Links!     Computer Technical Help     Programming International Forums     Deutsch         BBV [German]     Français     Two Plus Two en Espańol

All times are GMT -4. The time now is 09:05 PM.

 Contact Us - Two Plus Two Publishing LLC - Privacy Statement - Top