Nassau

A Nassau is the oldest and most popular bet in golf: three matches inside one round. The front nine is one bet, the back nine is another, and the full eighteen is a third. Each is match play, and the back nine always starts all square — so a wrecked front nine costs you one bet, not the day.

The core rules

1. Three separate bets: holes 1–9, holes 10–18, and holes 1–18.
2. Each is decided by holes won. Win a hole and you go one up; lose one and you come back one; halve it and nothing moves.
3. The back nine starts all square, whatever happened on the front.
4. A match ends the moment it is mathematically decided — three up with two to play is “3 & 2”, and the remaining holes cannot change it.
5. A match that finishes level is halved: nobody pays.
6. Each bet pays its agreed value once. Winning five up pays exactly what winning one up pays.

A “10-10-10 Nassau” means ten points on each of the three. That is the whole game before presses.

A worked example

Anna and Björn play a 10-10-10 Nassau:

Holes	What happened	Result
1–8	Anna wins holes 1, 3 and 4; Björn wins hole 6; the rest are halved	Anna wins the front, 2 & 1 — 10 points
10–14	Björn wins all five	Björn wins the back, 5 & 4 — 10 points
15–16	Halved	Björn is three up with two to play
16	The overall is decided	Björn wins the overall, 3 & 2 — 10 points

Björn finishes 10 points ahead — and every one of the three bets was over before its last hole. The front paid at hole 8, the back at 14, the overall at 16. If the group had walked in after hole 16, all three would still stand. That is what match play does and what a stroke total cannot: a bet ends when it can no longer be lost.

Presses

A press is a new bet over the holes that remain. A side that is two holes down can start one, and it runs to the end of that segment at the same value — so a front-nine press opened after hole 4 covers holes 5–9 and settles separately. A press can itself be pressed if it goes two down.

In AleaGolf presses are automatic and off by default. Turn them on and you choose how many holes down opens one, what it is worth, and how deep pressing may go. Requested presses — where the trailing side asks and the other side accepts — are not in the app yet.

Common variants

Variant	What changes	In AleaGolf
Automatic press at 2 down	A new bet opens by agreement, not by asking	Supported — off by default
Requested press	The trailing side asks; the other side may decline	Not yet
Re-press	A press that goes two down may itself be pressed	Supported, bounded by a depth limit
Different values per segment	The back nine or the overall is worth more	Supported
Team Nassau	Two sides of two play the same three matches on their better ball	Supported as its own game
Medal Nassau	Each nine is decided by total strokes instead of holes won	Not supported — a Nassau is match play

How AleaGolf plays it

These are the exact rules the app implements — the same logic our automated test suite checks on every release:

• Competitors: two players, or two sides of two. Nassau is head-to-head; a three-ball is offered a game that actually suits three.
• Scoring basis: gross or net, chosen at setup. Net is strokes off the low — the lowest handicap plays off scratch and everyone else receives the difference, allocated on the hardest holes by stroke index. The app preselects net whenever the handicaps differ.
• Settlement: each match pays its value once, at the hole where it was decided. The margin — “4 & 3”, “2 up” — is shown everywhere, and never multiplies what is paid.
• Closed matches stay closed: once the front nine is won, later holes cannot reopen it, but they still count for the overall match and any live press.
• Nine-hole rounds: one match for one value. Paying a “front” and an “overall” for the same nine holes would pay the same win twice.
• Incomplete holes: a hole where either side has no score moves nothing and counts as still to play, so a missing card delays a close-out instead of inventing one.
• Partial rounds: walk in early and every match already decided stands; the rest pay nothing.
• Score corrections: matches are recomputed from current scores, so a fixed card re-settles whatever depended on it.
• Points, never money: AleaGolf tracks side games in points and tokens. What the group does with the final standings is up to the group.

During the round, the Side Games tab shows all three matches side by side — front, back and overall — each in match-play language, so the group always knows which bets are still alive and which are already won.