What to lead

Ask questions, discuss and debate your strategies, euchre polls and more
Post Reply
sdu754
Posts: 46
Joined: Sat Jan 23, 2021 3:15 am

What to lead

Unread post by sdu754 » Thu Jan 19, 2023 4:49 pm

You are in the first seat with Ac, As, 9s, 10h, 9d

The second seat ordered up the 10c.

The score is 5-6

What is the best lead in this situation?

I think Raydog could analyze this one.



Tbolt65
Posts: 824
Joined: Sun Jun 16, 2019 9:14 pm
Location: Las Vegas

Unread post by Tbolt65 » Fri Jan 20, 2023 5:06 pm

I'm leading the 10h or the 10 of diamonds. Not leading an Ace here until trump gets pulled. Trying to get my partner to take a trick or possibly the makers in the lead and get trump out to make My aces good for stopper.


Tbolt65
Edward

raydog
Posts: 260
Joined: Thu Sep 16, 2021 6:56 pm

Unread post by raydog » Sat Jan 21, 2023 12:43 pm

I would personally play the low H or D here, as would my simulator.

When I tested leading other cards, here is what I found:
S2 bids with partner, S1 leads: [22,461 of 100,000 hands]
9D: EV = -1.14
AS: EV = -1.18
AC: EV = -1.21
So not much to distinguish the different leads, but a trash card looks like a good bet. You are not going to do well on this hand.

S2 bids alone, S1 leads: [3935 of 100,000]
9D: EV = -2.17
AS: EV = -2.20
AC: EV = -2.45
Once again, pretty close, but may as well stick with the general rule of not leading the AS.

irishwolf
Posts: 1321
Joined: Tue Apr 24, 2018 9:33 pm

Unread post by irishwolf » Sat Jan 21, 2023 3:45 pm

Ray, I have a couple comments:

For Part 1 what are the Sweeps / 1 pt / Euchres for leading 9D, AS & AC for the 22,461 hands?

Secondly, do have or know what Hal orders with for just having 2 trumps? And can you post just the results for having 2 trumps for 9D AS & AC (especially AC)?

This the real essence of this hand, IMO.

IRISH

sdu754
Posts: 46
Joined: Sat Jan 23, 2021 3:15 am

Unread post by sdu754 » Sat Jan 21, 2023 4:14 pm

raydog wrote:
Sat Jan 21, 2023 12:43 pm
I would personally play the low H or D here, as would my simulator.

When I tested leading other cards, here is what I found:
S2 bids with partner, S1 leads: [22,461 of 100,000 hands]
9D: EV = -1.14
AS: EV = -1.18
AC: EV = -1.21
So not much to distinguish the different leads, but a trash card looks like a good bet. You are not going to do well on this hand.

S2 bids alone, S1 leads: [3935 of 100,000]
9D: EV = -2.17
AS: EV = -2.20
AC: EV = -2.45
Once again, pretty close, but may as well stick with the general rule of not leading the AS.
I saw this in another forum, and I didn't know what the best lead would be. As you say, it is extremely close if seat two doesn't go alone. If seat two is going alone then either a low Diamond or Heart is automatically for while holding the offsuit Ace for the last trick.

raydog
Posts: 260
Joined: Thu Sep 16, 2021 6:56 pm

Unread post by raydog » Mon Jan 23, 2023 11:56 am

Irish:

I have broken down the results. It's difficult (virtually impossible) to simply define what hands S2 bids [as I've written to you personally], so I'll ignore that part [it's based on intermediate variables calculated by the program, based on hand strength and non-trump strength - very non-linear].

Let's start with the probability that S2 has 2, 3, 4 or 5 trump (the instances they might bid). The odds are:
- 2 trump: 25.8% [will bid with a strong hand, sometimes alone]
- 3 trump: 9.1% [will always bid, sometimes alone]
- 4 trump: 0.8% [will always bid, usually alone]
- 5 trump: 14 of 100,000 hands [will always bid alone]

And here is the breakdown:
Bid with partner, S2 has 2 trump: [15,996 of 100,000 games]
lead 9D: (5,333 / 9,486 / 1,177) [sweep / 1 pt / euchred] EV = 1.11
lead AS: (5,371 / 9,633 / 992) EV = 1.15
lead AC: (6,475 / 8,453 / 1,068) EV = 1.20
THESE EV's ARE FROM THE PERSPECTIVE OF S2! So, given you are S1, the lower the better!

Bid with partner, S2 has 3 trump: [6,467 of 100,000 games]
lead 9D: (1,881 / 4,338 / 248) [sweep / 1 pt / euchred] EV = 1.18
lead AS: (2,191 / 3,989 / 287) EV = 1.21
lead AC: (2,171 / 4,037 / 259) EV = 1.22

Bid alone, S2 has 2 trump: [797 of 100,000 games]
lead 9D: (463 / 287 / 47) EV = 2.57
lead AS: (431 / 285 / 81) EV = 2.32
lead AC: (533 / 246 / 18) EV = 2.93
THESE EV's ARE FROM THE PERSPECTIVE OF S2! So, given you are S1, the lower the better!

Bid alone, S2 has 3 trump: [2,647 of 100,000 games]
lead 9D: (974 / 1,638 / 35) EV = 2.06
lead AS: (1,022 / 1,592 / 33) EV = 2.12
lead AC: (1,162 / 1,480 / 5) EV = 2.31

Interpretation (by me):
- if S2 has 2 trump (in this particular situation, so given the remaining trump), they will bid about 65% of the time.
- if S2 has 3 trump (or more) trump, they will always bid
- the overall EV's are consistent between bidding with 2 or 3 trump [this is an internal check for me; my program doesn't favor one vs. the other]
- there is some advantage to leading the AS if S2 only has 2 trump and is going alone (understandable, if you make them expend one of those valuable trump), but you could never know this.
- I see no difference in strategy dependent on how many trump S2 holds (which is something you could never know, anyway).

[if the numbers in the above simulations don't add up to the 3rd or 4th decimal, it is because I had to run multiple scenarios, which aren't all equal. But close enough]

So I stick by my original analysis.

irishwolf
Posts: 1321
Joined: Tue Apr 24, 2018 9:33 pm

Unread post by irishwolf » Mon Jan 23, 2023 12:35 pm

PERFECT! Some good stuff to ponder over. Thanks the extra work on this.

But I was a little surprised that leading the AC when S2 orders with 2 trumps that the Euchre rate wasn't higher. I think Hal is on the money. Cool!

IRISH

Post Reply