What do you
lead first?

You're eldest hand (left of the dealer), the other team called trump, and the opening lead is yours. Pick the card that hurts the makers most.

Ace first — except 1 trump with scattered 2-1-1 going for a euchre. Then singleton. Dump the 9. Pull trump only when it's dead or you've got a fistful.

Tap it out

Lead finder

Answer the table in front of you and get the call. Same logic as the decision tree below.

If you only read one thing

The 30-second version

  1. Special shape first: 1 trump with side suits 2-1-1 → see the exception below.
  2. Hold an off-suit ace?Lead it. Best overall: ~11.9% euchre, ~76% kept to 1 point.
  3. 3+ trump?Lead your lowest trump.
  4. Singleton side suit?Lead that lone card (usually a 9 or 10).
  5. Doubleton? → Lead the 9 if you have one; otherwise the high card (K from K-10, K from K-Q).
  6. Three-card suit with an ace? → Lead the ace or middle card — never the 9.
  7. No ace, no reason to pull trump? → Lead your shortest side suit, low.
  8. Default: avoid leading trump. Across all hands, trump leads gave up 2 points ~30% of the time vs ~24% for a good off-suit lead.
The one shape that splits

1 trump + 2-1-1

The only place the two defensive goals genuinely disagree. Decide your priority, then lead.

Exactly 1 trump · side suits 2-1-1 · 115,127 hands
Your hand: [ 1 trump ] [ doubleton ] [ singleton ] [ singleton ]

Your lone low trump is probably getting dragged out next time trump is led, so saving it often buys nothing.

If you're chasing a euchre
Lead your lowest trump
11.95% euchre rate — best in this bucket
If you're stopping a 2-point hand
Lead a singleton or off-suit ace
74.6% kept to ≤1 point — safer line
LeadEuchredKept ≤1 ptGave 2 pts
Lowest trump11.95%70.27%29.73%
Off-suit ace9.99%73.91%26.09%
Singleton / short low9.95%74.64%25.36%
The data, by shape

Reference tables

Best picks in red. Swipe a table sideways for the full row.

By trump count & side-suit shape

You holdShapeBest for euchreEuchredBest to prevent 2Kept ≤1
0 trump2-2-1Off-suit ace10.6%Off-suit ace72.6%
0 trump3-1-1Off-suit ace9.6%Off-suit ace70.7%
0 trump3-2Off-suit ace9.3%Off-suit ace69.4%
1 trump2-1-1Lowest trump11.95%Singleton / ace74.6%
1 trump2-2Off-suit ace13.5%Off-suit ace80.4%
1 trump3-1Off-suit ace13.4%Off-suit ace78.9%
2 trump2-1Short side, low19.2%Same87.5%
2 trump1-1-1Lowest trump14.5%Side-suit lead73.2%
2 trump3-cardOff-suit ace26.6%Off-suit ace91.2%
3 trump1-1 / 2Lowest trump28–37%Lowest trump93–96%

Doubleton: which card?

DoubletonLeadAvoidEuchred (low / high)
K-99K10.98% / 10.83%
Q-99Q10.88% / 10.68%
J-99J10.27% / 9.78%
K-10K1010.40% / 10.98%
Q-1010Q10.63% / 10.38%
K-QK or Q~11.4% / 11.4%
Lead the 9 when you have one; else the honour with 10/J/Q.

Singleton

SingletonBest playEuchred
9Lead the 911.5%
10Lead the 1011.0%
KOff-suit ace if held, else the K12.4%

Three-card side suit

SuitBest leadWorst lead
A-K-9Middle (K) or ace9 — only 9.85%
A-Q-10Ace (high)Low
A-Q-9Ace (high)Low
K-Q-10High or middleLow
With an ace in the suit: lead ace or middle. Dump the 9 last.

Overall rankings · 375k hands

LeadEuchredKept ≤1Gave 2
Off-suit ace11.89%76.0%24.0%
Shortest suit, high11.61%76.5%23.5%
3-card suit, high11.60%76.0%24.0%
Lowest trump11.50%70.0%30.0%
Singleton11.47%76.1%23.9%
Shortest suit, low11.47%76.1%23.9%
Lowest trump keeps pace on euchre rate but is far worse at preventing 2 points.
Habits to drop

What not to do

  • Say "always lead trump, they'll pull it anyway."Only true in specific shapes (1 trump + 2-1-1 for a euchre chase; 3+ trump). Globally, trump leads gave up 2 points ~30% vs ~24% off-suit.
  • Lead trump on 1 trump with 2-2 or 3-1 side suits.The off-suit ace wins on both euchre rate and preventing 2 points.
  • Lead trump on 2 trump when you hold a good singleton.In a 2-1 shape, a side-suit low euchred ~19% and kept them to 1 point ~87.5%.
  • Lead the 9 from A-K-9.9.85% euchred vs 12.37% for the middle K.
  • Lead low from a K-10 or K-Q doubleton.Lead the honour, not the 10 or Q.
Run the play

Worked examples

Gold-ringed card is the lead. Trump is hearts in every example.

0 trump

2-2-1

Trump — no hearts, no left bower (J) in hand.

A K 9 Q 10

Lead the A♠ — off-suit ace. No ace? Lead low from a doubleton (the 9♦) or a singleton.

0 trump, no ace

2-2-1

Trump .

K 9 Q 10 J

No ace → lead the J♣ (singleton). From the K-9, you'd lead the 9♠, not the K.

1 trump — the exception

2-1-1

Trump . One trump, spades doubleton, two singletons.

9 K 9 10 J
Chase a euchre
9♥ — lowest trump (11.95%)
Stop a 2-point hand
10♦ or J♣ — singleton (74.6%)

2 trump

2-1

Trump .

9 10 K 9 J

No ace → lead the J♦ (singleton) or the 9♠ from the doubleton. Don't lead trump here.

0 trump, no ace

3-2

Trump .

K 10 9 Q 10

From the 3-card club suit, lead the K♣ (middle/high) — not the 9♣.

Phase D · tricks 2–5

After trick 1

The opening lead is one card of five. Here's what 375k hands say about the next four — opening lead fixed to the cheat-sheet pick, only your tricks 2–5 policy varies.

Who wins trick 1
72.7%
14.9%
12.3%
They (makers) You Partner

Most hands you lost trick 1, so your follow-up matters most there. Across every policy tested the gaps are small (~0.2–0.7 pts of euchre rate), with one clear loser: leading trump aggressively is consistently worst.

React to whoever won trick 1

They won ~73% · the big one

  • Win the tricks you need with your cheapest winning card — not the ace when a 10 does the job.
  • Don't passively hoard every ace and king for "later" — slightly worse than just playing.
  • Don't strip suits on autopilot to get void — it isn't a real gain here.
  • Don't lead trump unless you're void and trumping in.

You won ~15%

  • Lead your next strong side card, or a low card from a short suit.
  • Don't blindly cash every ace/king on trick 2 — generic play edges out "cash everything."
  • Don't lead trump without a clear reason.

Partner won ~12%

  • Support them: dump your lowest card while they're winning.
  • Don't over-trump or burn an honour for no reason — let partner run the hand.

What should my last card be?

Two ideas that sound alike but aren't:

Bad habit
"Hold the highest till the end" — refusing to play your A/K even when you should. Phase D says this is slightly worse.
Normal
"You'll often have one card left on trick 5" — fine. The only question is whether that card can still win a trick.
Good to still hold late
  • A boss off-suit — an ace, or a king in a suit whose ace is already gone.
  • Trump — to ruff in when they lead a suit you're void in (not "saved for last").
  • A second winner — two cards that can still take tricks means euchre territory.
Bad to be holding on trick 5
  • Dead junk — a 9 or 10 in a suit where the ace/king already showed and trump is gone.
  • An honour you never used — you sat on the ace throwing 10s while they marched.

Win cheap, spend honours last

Partner is winning this trickThrow your worst card
You must win or they marchWin with the cheapest card that wins
Trick already won or lostDon't burn your only boss
Example
They lead hearts; their K♥ is winning and you hold A♥ and 10♥. Play the 10 — same result, the ace stays for later.
Example
Partner is winning and you hold A♠ and 9♠. Throw the 9, not the ace.

Spend garbage early. Spend honours only when the trick is yours to take. What you want left is your last winner or a trump — not "always save the highest card."

The policy numbers

Differences between follow-up policies are small; baseline (generic play) holds up well and trump-aggressive is worst in every segment.

All hands

PolicyEuchredKept ≤1Gave 2
Baseline (generic)12.50%75.06%24.94%
Cash winners12.47%75.06%24.94%
Adaptive12.27%75.05%24.95%
Hoard honours12.26%75.05%24.95%
Strip suits12.14%74.95%25.05%
Trump aggressive11.76%74.95%25.05%

They won trick 1 (~73%)

PolicyEuchredKept ≤1Gave 2
Cash winners7.36%65.71%34.29%
Baseline7.32%65.71%34.29%
Hoard honours7.20%65.70%34.30%
Strip suits7.11%65.56%34.44%
Trump aggressive6.99%65.56%34.44%

You won trick 1 (~15%)

PolicyEuchred
Baseline22.30%
Cash winners21.96%
Hoard honours21.56%
Strip suits21.48%
Trump aggressive20.11%
Everyone keeps them to ≤1 pt here — you already have a trick.

Partner won trick 1 (~12%): baseline wins again (~31.2% euchre). Support partner — dump low when they're winning; don't over-trump or burn honours.

Re-run: python main.py --phase-d --hands 375000

Seat flips · now your team calls
Phase E · making trump

Calling it

Everything above assumes they called and you defend. This is the other chair: when should you take the bid, and when should you drop your partner and go alone?

When to call

Round 1 — order up avg −0.08 / hand

  • Almost always pass. As eldest with the dealer on the other team, ordering up just hands the up-card to your opponent.

Round 2 — name trump avg +0.60 / hand

  • Call with 3+ trump, a bower plus trump, or 2 trump with an off-suit ace or a void.
  • This is your team's normal path — a reasonable default to call on.

When to go alone

Default is keep your partner — 0.78 vs 0.53 avg maker points, and a loner gets euchred ~60% of the time vs ~34% with help. Only drop them when the hand is genuinely big:

Your handVerdict
Both bowersAlone — slightly better
4+ trumpAlone — much better
Monster hand (eval 9+)Alone — much better
Strong hand (eval 7–8.9)Alone — slightly better
2 trump · 1 trump · no bowerKeep partner — not close
4+ trump alone: 2.14 vs 1.44 avg points.

What a calling hand looks like

You never need to add up a score at the table — just recognize the shape. Trump is hearts here, so J♥ is the right bower and J♦ is the left bower (both play as hearts).

Strong — alone candidate

≈ 7

Right bower plus trump A, K, 9 — four trump, mostly high.

J A K 9 10

Very strong call. With bowers and real trump length like this, going alone is slightly ahead in the sim.

Monster — clear loner

9+

Both bowers, trump ace and king, plus an off-suit ace.

J J A K A

This is loner territory — alone beat keeping partner clearly in Phase E.

How "eval" is scored

Eval is the sim's hand-strength number for a chosen trump suit — not a rulebook rule. It adds up roughly how many winners you'd hold if that suit were trump, then buckets the total. You don't compute it at the table; the buckets do the work.

What you hold (in trump)Points
Right bower (J of trump)3.0
Left bower (same-colour J)2.5
Trump ace2.0
Trump king1.5
Trump queen1.0
Trump 9 or 100.5 ea
Off-suit ace+1.0 ea
Void in a side suit (with trump to ruff)+0.5 ea
BucketScoreWhat it means
Below call< 3.5Usually pass
Marginal3.5–4.9Thin call
Solid5.0–6.9Good call — keep partner
Strong7.0–8.9Alone candidate — the floor for going it alone
Monster9.0+Alone often right
Thresholds: call ≥ 3.5, go alone ≥ 7.0.

In plain terms: you want to clear 7.0 before dropping your partner — roughly both bowers, or a bower plus real trump length and some off-suit help. Below that, keep partner even on a confident call.

Re-run: python main.py --phase-e --hands 375000

Where the numbers come from

Method & deep cuts

How the simulation works

375,000-hand Monte Carlo simulation (seed 42), stick-the-dealer on, realistic calling hands. The same deals are replayed under each strategy so comparisons are fair.

You're eldest; the dealer's team called on a realistic hand. After your lead, all players use the same basic heuristic — not expert human play. Phase D layers your own tricks 2–5 policy on top of that. Bidding is a simplified model.

Best vs worst strategies differ by ~1–2 points on euchre rate: strong guidance, not gospel.

Re-run anytime: python main.py --segmented --hands 375000, --phase-c, or --phase-d

Ace variants — when you hold an off-suit ace

182,951 hands. Verdict: when you have an ace, lead it. Don't lead small from A-x instead.

StrategyEuchredKept ≤1Gave 2
Lead ace always12.68%78.24%21.76%
Ace only if singleton11.94%78.10%21.90%
Shortest side suit low11.83%77.83%22.17%
From A-x, lead small11.09%73.94%26.06%
Two doubletons (0 trump, 2-2-1)

57,422 hands. With no ace, lead the singleton — not a doubleton. Which doubleton you'd pick made no difference.

StrategyEuchredKept ≤1Gave 2
Off-suit ace10.63%72.56%27.44%
Singleton9.96%72.22%27.78%
Doubleton low8.88%68.61%31.39%
Lead the dealer's discard suit?

374,282 hands. Leading the suit the dealer threw away on pickup is not better than ace or singleton. Interesting idea, but the ace still wins.

StrategyEuchredKept ≤1Gave 2
Off-suit ace11.87%76.01%23.99%
Singleton / short low11.46%76.11%23.89%
Dealer's discard suit (low)11.21%74.74%25.26%
Conditional trump pull

Don't always pull trump. Use the conditional rules: 1 trump + 2-1-1 → low trump if chasing a euchre; 2+ trump with no ace → pulling is reasonable; always pulling is the worst on giving up 2 points.

StrategyEuchredKept ≤1Gave 2
1 trump + 2-1-1 (smart pull)12.49%74.92%25.08%
Off-suit ace always11.89%76.03%23.97%
2+ trump, no ace11.80%75.21%24.79%
Always lowest trump11.50%70.00%30.00%
Other findings

Who called? Almost all hands are dealer pickup (374,282 of 375,000), so results match the overall table. The dealer's-partner-called bucket is only 703 hands — too small to trust fully.

Stronger partner AI: teaching the partner to trump when void did not improve results — euchre rates dropped slightly. The opening-lead rankings were unchanged, so the conclusions don't depend on a super-partner.