The four Vegas arguments no rules page answers.
Everyone can explain Vegas until something weird happens. Both teams birdie. Somebody makes a 10. An eagle and a birdie land on the same hole. Then it’s four guys in a parking lot with four confident opinions and no source.
Here are the four that actually cause it, what the sources say, where they genuinely disagree, and what our engine pays — including the ones where we had to make a call because nobody has documented an answer.
Both teams birdie the same hole.
This one isdocumented, and it’s still the most common argument, because the intuitive read is that both teams flip each other and the hole gets enormous. It doesn’t. A flip is something you do to your opponent, and when both sides earn one they cancel out.
The flips cancel. Both team numbers stay low-first and you score the hole straight.
The Fried Egg: “If both teams make a birdie, the numbers remain in the original order.” Golflink and Cleek agree.
What our engine does: Cancel. Same for both teams eagling — blocks the flip and the double.
Somebody makes a 10.
This feels wrong the first time and it’s correct: pairing low-first would turn a blow-up hole into a catastrophe so large it stops being a golf bet. Reversing at 10 keeps the number survivable.
Note the disagreement — Cleek scores 6 and 10 as 610. If your group uses that convention, agree it on the first tee, because it changes what the hole is worth by hundreds of points.
The double-digit score goes FIRST — the one exception to low-first. A 4 and a 10 is 104, not 410.
18Birdies, golf.com, Golflink and PGA.com all state the reversal. golf.com: “a 115 isn’t ideal, but it’s a heck of a lot better than a 511.” Cleek is the outlier and keeps the lower score first.
What our engine does: Higher score first at 10 or above. 4 & 10 → 104. 10 & 12 → 1210.
An eagle on one side, a birdie on the other.
This is a genuine gap in the published record, not an oversight in our reading. The sources establish that matching achievements cancel; they never say what happens when the achievements differ.
We extended the cancel principle rather than invent a hierarchy, and we’re flagging it as a judgment call rather than dressing it up as canon. If your group rules that the eagle’s double survives, that’s defensible too — just decide it before it costs somebody money.
Not settled. No source we could find rules on it — the published rules cover both-birdie and both-eagle, and stop.
The Fried Egg covers both-birdie and both-eagle cancels; nobody addresses the mixed case. Extrapolating from that cancel logic is the only defensible route.
What our engine does: Total cancel. Under-par on both sides cancels the flip AND the eagle’s doubling.
You have to flip a three-digit number.
Follows directly from argument 2. Once a 10 puts a three-digit number on the board, the birdie flip has to do something to it, and no rules page says what.
Defining a flip as an order reversal keeps it consistent with the two-digit case, where flipping is also just reversing the pair.
Undocumented. Nobody writes down what flipping a 104 even means.
No source addresses a flip applied to a double-digit team number.
What our engine does: A flip reverses the pairing order, so 104 ↔ 410. The rule is “reverse the order,” not “sort the digits.”
Why you should believe any of this
We wrote the rules down before we wrote the engine — every ruling above traces to a named, dated source, and the handful with no source are labelled as our call instead of being quietly asserted.
Then we wrote assertions against that sheet and made the engine pass them. They caught a bug in our own math before anybody played a round on it. The suite runs on every push.
Run it yourself:
node scripts/verify-vegas-banker.mjs→ 60 passed, 0 failed (as of August 2026)That suite covers Banker too — the count is for both games together.
We do it this way because a money game runs on trust, and trust in a scorer is unusual: you can’t check its work mid-round, and by the time you’d notice it was wrong, everyone has already paid up and gone home. So the only version of this we’re comfortable shipping is one where the rules are written down in public and the tests are yours to run.
Score your next Vegas round on it.
Free, no account, no install. The flip, the eagle, the 10 and the settle-up are all handled — and if your group plays a variant, most of it toggles.
Open the scorer →Also worth a read: the four Banker arguments →