01-17-22 OE Monday - got euchred

[Dlan]

https://worldofcardgames.com/#!replayer ... %3A1%7D%5D

[LeftyK]

1st mistake - if you call s2r2 never EVER not trump in on first trick if you can. period. how the rest pans out is up for debate. I would lead my singleton red after winning 1st trick. but if you led the doubleton and third doesn't hit hard with left then you make the bid anyways. but you cannot let the 1st trick slide by; not on a second round bid from second chair.

[Wes (aka the legend)]

https://worldofcardgames.com/#!replayer ... %3A1%7D%5D

S1 played this hand poorly. He can't pass-pass with that holding. Holding 3 trump in the first round with no where to go in the 2nd round, S1 must grit his teeth and make that call. We have lots of good data on this spot showing that calling in the first round has a higher expected outcome than pass-pass or pass-call next with nothing. I've done some work on this spot and so has Ray. This spot is no longer debatable. S1 has to make that marginal 1st rd call. Yes that play probably has a negative expected outcome but passing has a worse negative expected outcome. This is like spliting 88s vs a T at blackjack. It's a losing play but it loses less than hitting or standing pat on your 16, so you have to do it.

S2: Standard 2nd round call. I have no problem with him playing off on the first lead. I do it all the time in that spot. It's possible that trumping in right away and leading the turned down suit (QC) on 2nd street is better. But until proven otherwise, I see nothing wrong with S2 playing off on 1st street. S2 most likely needs his P to take a trick somewhere. Playing off on 1st street and giving his P a chance to take that trick is fine play to me. Might as well give his P a chance right away as S2 is vulnerable to getting overtrumped on the first lead given that he doesn't close the action.

S2's big mistake is he panics on 3rd street and leads the Right for no good reason. Tricks are tied 1-1, and S2 holds the Right with no off aces to promote. With effectively only needing one more trick to scratch out a point, this is a classic "go fishing" spot for S2. S2 should lead his garbage hoping his P can pick up a trick. And even if his P doesn't win that trick all is not lost. If instead S3 takes the trick S2 could achieve a successful endplay with a some kitty help or some card luck.

[raydog]

Responding to Wes's response:

1) The first thing I also noticed is that S1 should not have passed, R1. I ran a simulation which bore this out: not a great result when calling trump, but still better than when passing [another way of thinking about this: when S1 passes R1, with no reasonable R2 bid, they are giving the opponents 4 chances to bid [twice with the given trump suit, twice with a trump suit of their choice] while only giving their own team 2 opportunities to bid - and the R1 bid from 3rd seat is particularly unfavorable and unlikely. This is defensive play.]

2) I then looked at situations where S2 gets a chance to bid R2 with the given hand and turn card (15,775 times out of 100,000). And, further, where S1 leads a diamond. I tested 3 possible plays by S2:

play 9H: 864 / 11,563 / 3,348) [2 pts / 1 pt / euchred] EV = +0.42
play 10S, then lead QC, trick 2 [if win trick 1]: (966 / 11,801 / 3,008) EV = +0.49
play 10S, then lead 9H, trick 2 [if win trick 1]: (807 / 12,088 / 2,880) EV = +0.50

This result supports trumping from S2 on the 1st trick (as advised by LeftyK). As for which card to subsequently lead, R2, the jury is still out - I did not find a clear winner. I thought that leading a C would be better, because S4 may be void (having passed R1), but it is also a short suit. Inconclusive.

A caveat: since only 16% of hands make it to R2 for a potential S2 bid, there may be some bias from my program as to which subset of hands make it that far. On the other hand, my program currently passes from S1R1 (an error I must correct), so perhaps the results are not so different from the scenarios actually encountered.

On Wes's 3rd point, I can't opine. Too far into the hand to run a meaningful simulation - too many assumptions about previous play.

[Wes (aka the legend)]

Responding to Wes's response:

1) The first thing I also noticed is that S1 should not have passed, R1. I ran a simulation which bore this out: not a great result when calling trump, but still better than when passing [another way of thinking about this: when S1 passes R1, with no reasonable R2 bid, they are giving the opponents 4 chances to bid [twice with the given trump suit, twice with a trump suit of their choice] while only giving their own team 2 opportunities to bid - and the R1 bid from 3rd seat is particularly unfavorable and unlikely. This is defensive play.]

Yep. This is a leak that needs to be cleaned up. People just need to get comfortable with +EV negative reinforcement strategies, I.E. strategies that fail most of the time but are nevertheless correct. Humans are pretty much genetically designed to suck at those strategies but with study and practice one can reprogram oneself. This concept is even more important in poker. If one can take their game to that level where they master the negative reinforcement strategies they will crush almost any game.

2) I then looked at situations where S2 gets a chance to bid R2 with the given hand and turn card (15,775 times out of 100,000). And, further, where S1 leads a diamond. I tested 3 possible plays by S2:

play 9H: 864 / 11,563 / 3,348) [2 pts / 1 pt / euchred] EV = +0.42
play 10S, then lead QC, trick 2 [if win trick 1]: (966 / 11,801 / 3,008) EV = +0.49
play 10S, then lead 9H, trick 2 [if win trick 1]: (807 / 12,088 / 2,880) EV = +0.50

Just wanted to point out that the idea behind trumping in and leading the turned down suit on 2nd street is the fact that that's the suit S2's partner is most likely void in. I'm glad this idea is not "wrong" but I am surprised it's not more "right" as we basically have a statistical tie between that idea and leading the 9H on 2nd street.

This result supports trumping from S2 on the 1st trick (as advised by LeftyK).

Yes, this is a very interesting result! But we still have to test one more scenario that could easily be relevant. Say S1 leads a diamond like in this hand. We have to test the scenario where S2, the maker, throws off the QC. The idea of S2 getting rid of the QC on first street is his opponents most likely has that suit and is most likely boss in that suit given that S2's team turned that suit down in the first round, so S2 voiding himself in clubs could be more advantageous than voiding himself in other suits (hearts).

As for which card to subsequently lead, R2, the jury is still out - I did not find a clear winner. I thought that leading a C would be better, because S4 may be void (having passed R1), but it is also a short suit. Inconclusive.

Yep me too, but at least that idea is not wrong. It's just not as "right" as I thought it would be.

PS: One minor point I failed to mention that's not relevant for our exchange Ray, just something I forgot to mention in my other post: Given that S1 incorrectly pass-passed and the 2S called, I disagree with S1's 2nd round lead. I think leading the AC is the best lead in that spot.

[raydog]

Wes, I just tried discarding the QC instead of the 9H (other two plays are the same - trump, followed by QC or 9H lead). Worse outcome: EV = +0.36, vs. the same for the other two plays. Given that C is a VERY short suit (both 9c and JC gone), I think getting void in a 6-length suit would be far more valuable. So I'm not surprised by the result.

I'm also confused by your suggestion of a AC lead by S1 on 1st trick. With 9C buried, only the QC remains. (the fact that S4 passed is only relevant for the JC, which now counts a s a Spade). 2/3 chance it lies with an opponent BUT if S2 has it and S3 trumps, S4 can (likely) overtrump. So really a 50/50 proposition.

I'll leave it to you to simulate . Need to specify S1 cards and the turn, reach a bid by S2, and perhaps specify how S2 reacts to am AC lead by S1 - too far down the rabbit hole for me. Though I agree it is an interesting question.

[Wes (aka the legend)]

Wes, I just tried discarding the QC instead of the 9H (other two plays are the same - trump, followed by QC or 9H lead). Worse outcome: EV = +0.36, vs. the same for the other two plays. Given that C is a VERY short suit (both 9c and JC gone), I think getting void in a 6-length suit would be far more valuable. So I'm not surprised by the result.

Good stuff. That makes sense to me. Discarding the QC had to be ruled out cuz it had some plausibility. And I think you did that.

1'm also confused by your suggestion of a AC lead by S1 on 1st trick. With 9C buried, only the QC remains. (the fact that S4 passed is only relevant for the JC, which now counts a s a Spade). 2/3 chance it lies with an opponent BUT if S2 has it and S3 trumps, S4 can (likely) overtrump. So really a 50/50 proposition.

I'll leave it to you to simulate . Need to specify S1 cards and the turn, reach a bid by S2, and perhaps specify how S2 reacts to am AC lead by S1 - too far down the rabbit hole for me. Though I agree it is an interesting question.

I do think leading the AC in that spot is best. At the very least it will force out enemy trump which is still a positive thing. The fact that the AC is so dirty--only the QC left in the wild--wouldn't deter me from leading it. Just the opposite in fact. Against a 2S call this dirty lead could easily create an overtrump situation for our team. Our dirty AC lead puts S2, the maker, in a virtual squeeze sitsituation. That's a plus for S1-S3. Another thing, the AC is so dirty if we hold it back we'll probably die with it getting no use out of it. Leading the AC to force out enemy trump or to create a situation where the maker gets overtrumped is likely the only strategic value we can milk from it.

So yea I do think S1s lead in the actual hand is incorrect. I think leading the AC is best for his team. Whether that's true or not is a different story. But that's where my money is.

BTW I already feel like I'm wasting your valuable time getting you to test rather arcane spots. I don't wanna exhaust you. I know you have a life:-)

There's actually way more common and important spots that even experts can't disagree on. We should've done those spots first. For example, take this S1-R1 call (score 0-0):

Upcard:

S1:

Experts disagree on what's better to lead, offsuit or the Right. I think offsuit is best but who knows. We probably shoulda had a thread on these kinda common spots where there's lots of disagreement. As is, I've taken you down too many rabbit holes. Either way, I deeply appreciate all the work you have done Ray.

[raydog]

The scenario you give is very hard to simulate, because so much depends on how S1 plays subsequent tricks as the hand plays out.

As a first pass, I compared 3 different scenarios :
1) lead JS (R)
2) lead 9H
3) lead 9D
The last 2 should be identical, but because the way my program is set up, if S4 has identical singletons in H and D, they will discard the H [I haven't randomized this; the program goes through suits in order], so leading the 9D is more favorable by about 0.007 of EV. Small, but important to realize that there are biases introduced by my algorithm.

The difference between 1) and 3) is also less than 0.01 of EV, so it's either a toss-up OR dependent on how the hand is played. Here's how my program plays if the first lead is JS (right bower):
1) S1 keeps leading trump as long as they have the boss trump (so if the L falls on the first trick, AS is led trick 2; if 10S is the only trump left after 2 tricks, it is led on trick 3);
2) if L doesn't fall on trick 1, 9H is led.
3) if after 2 tricks the KS is still outstanding, lead 9H.

One scenario of interest: S1 leads the JS and draws trump from everyone, but not the L (so only the L outstanding); 9H is led, and S4 wins with the AH; S4 leads the KC on trick 3. What should S1 play?

If the L is with S3 (or buried), the game is secure. If it's with an opponent, it's more likely to be with S4. So trump in with the 10S? That's how the program currently plays. I would posit that this is the best way to win 5 tricks as well, if the opponents don't have the L.

It's possible that this situation really is a toss-up, but I want to be sure my program is playing as the experts would. Let me know if there are specific scenarios that experts would play a certain way, and that my program may be plating incorrectly. It would only take a few rather rare scenarios, played better, to tilt the balance in favor of leading the JS.

[raydog]

Upon further reflection, the decision tree becomes even more complicated if the 9H or 9D is led. Perhaps with expert play in every scenario, and perfect coordination with partner, one or the other leads by S1 trick 1 would prove a bit better. But my guess is it will be close. So my advice would be to lead the JS. Easier to play (less likely to make a "mistake" - suboptimal play) and less reliance on partner playing correctly. Too complex for me to try to simulate.

[Wes (aka the legend)]

The scenario you give is very hard to simulate, because so much depends on how S1 plays subsequent tricks as the hand plays out.

As a first pass, I compared 3 different scenarios :
1) lead JS (R)
2) lead 9H
3) lead 9D
The last 2 should be identical, but because the way my program is set up, if S4 has identical singletons in H and D, they will discard the H [I haven't randomized this; the program goes through suits in order], so leading the 9D is more favorable by about 0.007 of EV. Small, but important to realize that there are biases introduced by my algorithm.

That's ok. I don't think that should be a big deal. We can always just give S1 this hand to avoid that problem:

The difference between 1) and 3) is also less than 0.01 of EV, so it's either a toss-up OR dependent on how the hand is played.

Wow, regardless of how your programs plays the hand, that result--a statistical tie--is very interesting to me! It may suggest that we should lead the JS with other R+2+0 hands. Why is that? Becuz this hand was purposely picked by me becuz in theory it is one of the best possible hands to consider not leading trump becuz with this hand if we lead offsuit it's possible for us to trump in later in the hand and then set up an end play. IOW if we lead offsuit we can often get 3 tricks ourselves with this holding. I should've picked the best possible hand to try this tactic with (same upcard):

Here's how my program plays if the first lead is JS (right bower):
1) S1 keeps leading trump as long as they have the boss trump (so if the L falls on the first trick, AS is led trick 2; if 10S is the only trump left after 2 tricks, it is led on trick 3);

Looks good to me.

2) if L doesn't fall on trick 1, 9H is led.

Looks good to me.

3) if after 2 tricks the KS is still outstanding, lead 9H.

Looks good to me.

One scenario of interest: S1 leads the JS and draws trump from everyone, but not the L (so only the L outstanding); 9H is led, and S4 wins with the AH; S4 leads the KC on trick 3. What should S1 play?

Good question. Those times the left is in enemy hands we need our P to take a trick in offsuit. So at this point in the hand it comes down to which suit are we gonna hope our P can get? Diamonds or Clubs. If we throw off on S4's KC lead then we're obviously hoping our P has the AC. If we trump in, we're hoping our P has boss diamonds. Becuz it was the KC, I think it is better we trump in and gamble on diamonds. Why? Not just becuz there's always a chance that KC is boss but also becuz it's still possible S4 has ACKC and he's trying to trick us into playing off by playing the KC. So I would be very wary of a King lead in that spot.

So I think we're better off trumping in and gambling on diamonds. What complicates this problem tho is that IF S4 leads the KC that means he shouldn't have the Left. Why becuz if he had the Left he should lead it in that spot after that action. Assuming S1 started with 3 trump, S4 knows leading the Left cannot hurt his team as his P must be out of trump at that point, and those rare times S1 started with just 2 trump, leading the Left cleans out S1 and could potentially take out 2 enemy trump with 1 lead (the unfortunate risk/possibility of S4's trump lead taking out his P's trump along with S1's is worth it imo). So if S4 can't have the Left that means the Left is behind us in S2 in this scenario (we're only focusing on those hypothetical times the Left is in enemy hands cuz otherwise we get the point no matter what we do) So with the Left behind us in S2's hands there's a real risk to trumping S4's offsuit lead as we can now get overtrumped. I still think it's best for us to trump the KC and hope our P saves us in diamonds, but if S4 leads a QC or lower, it's probably best for us to play off avoiding the risk of getting overtrumped hoping our P saves us in clubs.

If the L is with S3 (or buried), the game is secure. If it's with an opponent, it's more likely to be with S4. So trump in with the 10S? That's how the program currently plays. I would posit that this is the best way to win 5 tricks as well, if the opponents don't have the L.

Yep, I would trump the KC with the TS for reasons stated. Even tho I said S4 should not have the Left once he leads the KC, we both know in real life he could easily have the Left. The fact that S4 could still have the Left makes trumping the KC even better cuz we are less likely to get overtrumped and S4 is even more likely to be tricking us with ACKC trying to get us to play off for the instant euchre. I agree that this is the best way to win 5 tricks if opponents don't have the L becuz the KC could be boss if the Ace is in the kitty.

It's possible that this situation really is a toss-up, but I want to be sure my program is playing as the experts would. Let me know if there are specific scenarios that experts would play a certain way, and that my program may be plating incorrectly. It would only take a few rather rare scenarios, played better, to tilt the balance in favor of leading the JS.

Ok let's go back to the hand and I'll go over some common scenarios after I lead offsuit:



1) Say I lead the 9H and my partner wins the trick. On 2nd street they should always lead trump. If they don't have that, lead an off ace. If they don't have an off ace probably lead Next as S1 is most likely void in that suit. Most critically S3 should never double lead hearts back if he can help it.

2) I lead the 9H, everyone follows suit and S4 takes the trick with the AH and then double leads another heart. We should always play off in this spot throwing away the 9D. Can't risk getting overtrumped.

3) I lead the 9H, S4 takes the trick (how he takes the trick is irrelevant) and then leads the 9C. We need to trump this trick with the TS and then lead our 9D to set up an end play.

Upon further reflection, the decision tree becomes even more complicated if the 9H or 9D is led. Perhaps with expert play in every scenario, and perfect coordination with partner, one or the other leads by S1 trick 1 would prove a bit better. But my guess is it will be close. So my advice would be to lead the JS. Easier to play (less likely to make a "mistake" - suboptimal play) and less reliance on partner playing correctly. Too complex for me to try to simulate.

I actually agree with you. For any new to intermediate player I would just tell them lead the Right. It simplifies everything and even if it's not always correct it's close enough. As far as your simulator, I wouldn't get too worried about all the decision trees. We both know your simulator isn't perfect becuz no simulator ever will be. Your simulator doesn't have to be "right" in the most strictest sense. It just has to be useful and my god is it useful. As I think you've mentioned before, when we find relatively big EV differences there's a great chance your simulator is pointing in the right direction and that in itself is strong evidence of what we should do in a particular hand. Critical evidence that is often impossible or highly impractical to get from a kitchen table sample.

My hypothesis is that whenever we have Right-Ace-X in trump with no off aces we should always lead offsuit on our S1-R1 calls becuz of the fact that we can set up an end play those times we trump in on 2nd street and then lead offsuit on 3rd street--if S2 takes that trick on 3rd street we're home free with our A-J of trump.

Just curious--according to your simulator (don't worry about it not being perfect), is this best possible hand to run this ploy with also a statistical tie?



Also, what about R+2+0 hands where we can't reliably set up an end play:

upcard:

S1:

Becuz we can't reliably set up an end play, is it best to just lead trump (JS)?

[raydog]

Found interesting results.

In the first scenario (I had QS as turn card), I found:
lead JS: EV = +0.60
lead 9H: EV = +0.68

Which supports your end-play theory.

But with the second scenario I found:
lead JS: EV = +0.06
lead 9H: EV = -0.25

Really need to draw trump! Also tested if lead the 9S: EV = -0.18.

[Wes (aka the legend)]

Found interesting results.

In the first scenario (I had QS as turn card), I found:
lead JS: EV = +0.60
lead 9H: EV = +0.68

Which supports your end-play theory.

But with the second scenario I found:
lead JS: EV = +0.06
lead 9H: EV = -0.25

Really need to draw trump! Also tested if lead the 9S: EV = -0.18.

This is great stuff man!! It leads me to formulate this hypothesis:

Those times you call from S1-R1, if you have R+2+0 always lead the Right unless you have J-A-X in trump, in that case lead offsuit and try to set up and end play.

That said I would predict this hand would be an exception tho:

Upcard:

S1:

The idea being one of our off Kings will be boss often enough to swings things back to leading the Right. If true, then I'd wonder what about 1 King:

Upcard:

[Wes (aka the legend)]

Found interesting results.

In the first scenario (I had QS as turn card), I found:
lead JS: EV = +0.60
lead 9H: EV = +0.68

Which supports your end-play theory.

But with the second scenario I found:
lead JS: EV = +0.06
lead 9H: EV = -0.25

Really need to draw trump! Also tested if lead the 9S: EV = -0.18.

This is great stuff man!! It leads me to formulate this hypothesis:

Those times you call from S1-R1, if you have R+2+0 always lead the Right unless you have J-A-X in trump, in that case lead offsuit and try to set up and end play.

That said I would predict this hand would be an exception tho:

Upcard:

S1:

The idea being one of our off Kings will be boss often enough to swings things back to leading the Right. If true, then I'd wonder what about 1 King:

Upcard:

Also it almost goes without saying that we should lead trump (R) with this J-A-X S1-R1 hand:

Upcard:



Since we can easily promote our diamond to boss status, better off leading trump and if the Left doesn't come out then lead offsuit. The only question with this holding is, is this a loner. It would certainly be a marginal one from S1-R1.

As far as leading trump it gets more dicey when we have an outside suited queen as we're not guaranteed to get our offsuit to boss status. So I'm not sure what lead is best with:



I intentionally did not reference this hand:



Because it now could be best to bag spades with the intention of calling hearts in the 2nd round.

[Tbolt65]

Upon further reflection, the decision tree becomes even more complicated if the 9H or 9D is led. Perhaps with expert play in every scenario, and perfect coordination with partner, one or the other leads by S1 trick 1 would prove a bit better. But my guess is it will be close. So my advice would be to lead the JS. Easier to play (less likely to make a "mistake" - suboptimal play) and less reliance on partner playing correctly. Too complex for me to try to simulate.

Don't turn into an Eric Zalas. It is these complicated decisions and hand recognition during actual play of the hand that is the difference maker. Something which is hard to program into setting parameters. When considering how and why to trump or play off for example. Or take into consideration your partners likely holdings. There are times that you need your partners help but when to employ that help is by how things play out and when you have no other choice but to trust your p to get 1 or your set. All theses things and more change on the fly. Its recognizing in the moment based on multiple factors. Some of which you just can't program.

From what I've been reading. You have been doing a good job. Where rigid parameters can be set. However that can only take one so far.

Tbolt65
Edward

[Wes (aka the legend)]

Don't turn into an Eric Zalas. It is these complicated decisions and hand recognition during actual play of the hand that is the difference maker. Something which is hard to program into setting parameters. When considering how and why to trump or play off for example. Or take into consideration your partners likely holdings. There are times that you need your partners help but when to employ that help is by how things play out and when you have no other choice but to trust your p to get 1 or your set. All theses things and more change on the fly. Its recognizing in the moment based on multiple factors. Some of which you just can't program.

From what I've been reading. You have been doing a good job. Where rigid parameters can be set. However that can only take one so far.

Tbolt65
Edward

I think it's actually the opposite. We can only get so far without Ray's simulator. For many gray area spots Ray's simulator is our only hope of finding a reliable answer. We can't get "to the nth degree" without it.

[Tbolt65]

Hand recognition will be needed. I dont know how to program that in. But I'm sure to get to that point. It is probably a tedious and arduous undertaking. Hence Rays comment on to keep it simple and lead the Jack.

Tbolt65
Edward