Effective Odds demystified

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scubed

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I have been studying David Sklansky's Theory of Poker. Participate in my journey in this thread: https://www.cardschat.com/forum/learning-poker-57/back-books-theory-poker-sklansky-375355/ Chapter 06: Effective odds is giving me some problems, I *think* I understand Effective Odds in Fixed Limit - but struggling :banghead: to determine how/when to apply the calculations in No-Limit.

Would someone please share your thought process and the NL hand where you applied Effective Odds to make a decision on whether or not to call the flop?
 
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Effective Odds - Sklansky Fixed Limit Example

TL;DR: :) In Limit Hold'Em - 2 handed (with equal stacks, no one in danger of all-in) when Hero hits 4 to a flush on the flop and faces a bet from Villain calling is NOT correct mathematically UNLESS Hero believes that Villain will call a bet on the river when the flush comes.
Sklansky provides a Fixed Limit Example for us to think about Effective Odds. I'll use Sklansky's example to mock up a hand for review so that we can further discuss. Our hero (BB) is trying to determine if he should make a call ON THE FLOP when drawing to a flush. Our mission is to determine if Hero is getting the correct Effective Odds to make the call ON THE FLOP.

The Game:
Fixed Limit Hold'Em $10/$20 (this makes SB = $5 and BB = $10)
Pre-flop/Flop betting increment $10.
Turn/River betting increment $20
Player stacks are EQUAL, each has $500 (no-one will be all in this hand)

Pre-flop:

  • Action folds around to the SB (cards unknown) who completes.
  • BB has :8h4: :jh4: and checks option
  • This means that two players will see the flop (SB/BB)
  • Current Pot Size $20

Flop: :as4: :2h4: :7h4:

  • SB bets $10 on the flop
  • Current Pot Size $30
  • BB is deciding if he should call $10 to win $30 or 3-to-1 pot odds
  • BB has 9 outs to make his flush.
    • 19.6% to make the flush on the turn (1 card) in ratio form 4.1:1
    • 35% to make the flush on the river (2 cards) in ratio form 1.9:1

Comparing the pot odds to the immediate odds when Hero (BB) only plans to see the turn (1 card) we have 3-to-1 pot odds against 4:1 chance of improving. Our calculations indicate that calling the flop is NOT a good call.

Comparing the pot odds to the immediate odds when Hero (BB) plans to see the turn/river (2 cards) we have 3-to-1 pot odds against 1.9:1 chance of improving. This calculation looks to indicate a good call on the flop BUT - it is not a correct comparison (we've used immediate odds) UNLESS the 2nd card is free (i.e. a player is all-in). In our scenario there are no players all-in, so we can expect that we will be faced with a bet and decision on later rounds. Effective Odds will help our Hero (BB) determine if he should call the flop based on predictive thinking about the turn/river rounds.

Turn: Hypothetical - Hero (BB) is deciding if he should call the flop

  • SB will potentially bet $20
  • BB needs to think about what he will win or lose in the hand
    • $10 call on flop + $20 call on turn = possible loss -$30
    • $30 (current pot on flop) + $20 (opponents turn bet) = possible win $50
  • Effective Odds are $50 to $30 or in ratio form 1.66-to-1
  • Predicted pot size following turn action = $80
Comparing our Hero is getting 1.66 Effective (real) odds to against 1.9:1 chance (seeing 2 cards) of improving. Our calculations continue to indicate that calling the flop is NOT a good call.

River: Hypothetical - Hero (BB) is deciding if he should call the flop

  • The :3h4: hits the board giving our Hero (BB) a flush!
  • Hero believes he will get paid off, that SB will call a bet on the river
  • BB needs to think about what he will win
    • $30 (current pot on flop) + $20 (opponents turn bet) + $20 (opponent calls Hero's river bet) = possible win $70
  • Effective Odds are $70 to $30 or in ratio form 2.33-to-1
Comparing (remember, our opponent MUST call the river) our Hero is getting 2.33 Effective (real) odds to against 1.9:1 chance (seeing 2 cards) of improving. Our calculations indicate that calling the flop IS a GOOD call.

In summary: In this Fixed Limit Hold'Em example I believe that Sklansky's point is that a player is making a mistake when he only considers the immediate odds - the "right now" - when he needs to draw to improve his hand. A great player takes into account the $$ the TOTAL amount he might win or lose, to make a good decision to call (or not) in earlier rounds.

If someone will confirm that I've understood and articulated this example from Sklansky's Theory of Poker (chapter 6) correctly - I'll attempt to perform the same kind of analysis on a No Limit hand OR even better - if someone else could try to demystify Effective Odds I'd love to learn from you! Anyone? :)
 
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Ok, I can't help you, but this definitively helped me. It clarifies things for me, and it makes sense.

To adapt this to no limit, you would need to guess what your opponent is likely to do on the next street. It makes it harder, but I feel like you can have a general idea of what's going to happen. Like if someone is betting on the flop, I would assume that person would make a bet of around the same proportion on the turn, and probably on the river too.


Does Sklansky say something about this in NLHE ?
 
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Does Sklansky say something about this in NLHE ?

Unfortunately, Sklansky did not give a detailed example with NLHE. I have also struggled to find one in internet searches.

I am thinking about trying to apply the same hand story but change the math to NLHE with the following profiles

  • TAG betting 1/2 on flop 3/4 on turn
  • LAG betting 3/4 on flop 3/4 on turn
  • TP betting 1/2 on flop 1/2 on turn
  • LP betting 1/4 on flop 1/4 on turn
  • NUT betting 3/4 on flop POT on turn
What do you think about the scenarios? Do they cover enough to teach us something?
 
polote21

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TL;DR: :) In Limit Hold'Em - 2 handed (with equal stacks, no one in danger of all-in) when Hero hits 4 to a flush on the flop and faces a bet from Villain calling is NOT correct mathematically UNLESS Hero believes that Villain will call a bet on the river when the flush comes.
Sklansky provides a Fixed Limit Example for us to think about Effective Odds. I'll use Sklansky's example to mock up a hand for review so that we can further discuss. Our hero (BB) is trying to determine if he should make a call ON THE FLOP when drawing to a flush. Our mission is to determine if Hero is getting the correct Effective Odds to make the call ON THE FLOP.

The Game:
Fixed Limit Hold'Em $10/$20 (this makes SB = $5 and BB = $10)
Pre-flop/Flop betting increment $10.
Turn/River betting increment $20
Player stacks are EQUAL, each has $500 (no-one will be all in this hand)

Pre-flop:

  • Action folds around to the SB (cards unknown) who completes.
  • BB has :8h4: :jh4: and checks option
  • This means that two players will see the flop (SB/BB)
  • Current Pot Size $20

Flop: :as4: :2h4: :7h4:

  • SB bets $10 on the flop
  • Current Pot Size $30
  • BB is deciding if he should call $10 to win $30 or 3-to-1 pot odds
  • BB has 9 outs to make his flush.
    • 19.6% to make the flush on the turn (1 card) in ratio form 4.1:1
    • 35% to make the flush on the river (2 cards) in ratio form 1.9:1

Comparing the pot odds to the immediate odds when Hero (BB) only plans to see the turn (1 card) we have 3-to-1 pot odds against 4:1 chance of improving. Our calculations indicate that calling the flop is NOT a good call.

Comparing the pot odds to the immediate odds when Hero (BB) plans to see the turn/river (2 cards) we have 3-to-1 pot odds against 1.9:1 chance of improving. This calculation looks to indicate a good call on the flop BUT - it is not a correct comparison (we've used immediate odds) UNLESS the 2nd card is free (i.e. a player is all-in). In our scenario there are no players all-in, so we can expect that we will be faced with a bet and decision on later rounds. Effective Odds will help our Hero (BB) determine if he should call the flop based on predictive thinking about the turn/river rounds.

Turn: Hypothetical - Hero (BB) is deciding if he should call the flop

  • SB will potentially bet $20
  • BB needs to think about what he will win or lose in the hand
    • $10 call on flop + $20 call on turn = possible loss -$30
    • $30 (current pot on flop) + $20 (opponents turn bet) = possible win $50
  • Effective Odds are $50 to $30 or in ratio form 1.66-to-1
  • Predicted pot size following turn action = $80
Comparing our Hero is getting 1.66 Effective (real) odds to against 1.9:1 chance (seeing 2 cards) of improving. Our calculations continue to indicate that calling the flop is NOT a good call.

River: Hypothetical - Hero (BB) is deciding if he should call the flop

  • The :3h4: hits the board giving our Hero (BB) a flush!
  • Hero believes he will get paid off, that SB will call a bet on the river
  • BB needs to think about what he will win
    • $30 (current pot on flop) + $20 (opponents turn bet) + $20 (opponent calls Hero's river bet) = possible win $70
  • Effective Odds are $70 to $30 or in ratio form 2.33-to-1
Comparing (remember, our opponent MUST call the river) our Hero is getting 2.33 Effective (real) odds to against 1.9:1 chance (seeing 2 cards) of improving. Our calculations indicate that calling the flop IS a GOOD call.

In summary: In this Fixed Limit Hold'Em example I believe that Sklansky's point is that a player is making a mistake when he only considers the immediate odds - the "right now" - when he needs to draw to improve his hand. A great player takes into account the $$ the TOTAL amount he might win or lose, to make a good decision to call (or not) in earlier rounds.

If someone will confirm that I've understood and articulated this example from Sklansky's Theory of Poker (chapter 6) correctly - I'll attempt to perform the same kind of analysis on a No Limit hand OR even better - if someone else could try to demystify Effective Odds I'd love to learn from you! Anyone? :)

thanks I had a similar situation a few days ago, with this information on what to do.
 
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thanks I had a similar situation a few days ago, with this information on what to do.

Hi -

Would you be so kind to explain the hand that you had a few days ago? Assuming the game was NLHE, was it tournament or cash? What position were you in? What position was your opponent in? What were the hold cards you had? What was the pre-flop action? What was the flop? What did your opponent do on the flop?

With this information we can attempt to work out the Effective Odds to see if your play was correct mathematically.
 
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FailX21

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Unfortunately, Sklansky did not give a detailed example with NLHE. I have also struggled to find one in internet searches.

I am thinking about trying to apply the same hand story but change the math to NLHE with the following profiles

  • TAG betting 1/2 on flop 3/4 on turn
  • LAG betting 3/4 on flop 3/4 on turn
  • TP betting 1/2 on flop 1/2 on turn
  • LP betting 1/4 on flop 1/4 on turn
  • NUT betting 3/4 on flop POT on turn
What do you think about the scenarios? Do they cover enough to teach us something?

Don't really know, but classifying people could be a good idea yeah, although you could make some adjustments in certain situations.
 
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AlexTheOwl

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What do you think about the scenarios? Do they cover enough to teach us something?


Yes, I think it is useful to work out how profitable it is to call flop bets with draws in various scenarios.

In NLHE, in practice:
- Your opponent can bet, or check, on any street
- His bets can be of any size (assuming both players are deep stacked)
- You also have the option to bet, or raise, on any street. This will often be the most profitable choice.
- Your bets or raises can be of any size
- Your opponent can fold, call, or re-raise in response to any bet you make.

That's a lot of variables.

If you know your opponent, or know the way typical opponents play in your game, you can estimate what actions he is likely to take, and how likely he is to take those actions.

I don't find it practical to work out a mathematical effective odds figure at the table. But working out the math for scenarios in advance helps make decisions on the table easier.

My actual thinking at the table regarding effective odds for the example hand in NLHE is more like:

This player completed from the SB. He didn't raise, although he raises unopened pots in late position about 40% of the time. So he probably doesn't have an Ace, a pair, or suited connectors, although maybe he is being sneaky.
He bet half pot on the flop. He's pretty tight and passive post-flop, so his bet on the flop probably represents a real hand - maybe a 7, a 2, or a flush draw, although occasionally he will bluff.
If I call, he'll probably check the turn if his hand does not improve, although occasionally he will bluff. If his hand does improve on the turn, he'll probably bet half-pot or more, and I'll need to fold.
He's not a calling station post-flop. So I can probably get to the river at no additional cost, but I probably won't win a large pot if I hit my flush. If I make my flush on either street, he'll probably pay off one half-pot bet about half the time.
Since his hand is probably weak, and he is not a calling station, I think he will fold about half the time if I bet 3/4 pot on the turn (if he checks the turn).
Sometimes I'll win 4 BB by betting the turn, sometimes I'll win 4 BB by making my flush, sometimes I'll win 6 BB by making my flush, and sometimes I'll lose 1 BB, sometimes I'll lose 6 or more BB if I make my flush and my opponent makes a better flush or a full house. I can't assign an exact probability to any of those outcomes. But I think the price is low enough, and the chances of winning are high enough, that I should call this flop.

You can see that there are many things we can change about the opponent that might change the effective odds.
The opponent might bet bigger on the flop. He might be passive pre-flop, increasing the chances that he has an A or another good hand that would pay off a bigger bet post-flop.
He might be more aggressive post-flop, or a calling station. He might raise pre-flop, and his usual range for raising might be wide or narrow, etc.

TL;DR, it's not practical to come up with an exact estimate at the table, and there are many factors to consider, but it is helpful to run some numbers away from the table.
 
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