Head-to-head teaser in the lobby: "Anna vs Ben 3-2"

[mholzi]

When two returning players are in the lobby, the TV shows the head-to-head: "Anna vs Ben: 3–2".

The code says it wants to do this. analytics.py:302 justifies the lobby standing by saying the line is "supposed to start a rivalry" — but only the solo view exists.

Anchor

analytics.py:296 — get_player_standing is strictly solo. Grep for rival|head.to.head|h2h: that one comment and nothing else. Pairwise wins are computable per game from GameRecord.player_scores.

Smallest valuable slice

The TV lobby (not the phones) shows the duel for the most-frequently-co-playing present pair.

The catch

Two, and the second is a decision rather than a detail:

1. Detailed games prune at RETENTION_DAYS = 90 / MAX_DETAILED_RECORDS = 1000. Labelled honestly it is "last 90 days"; anything longer needs a pairwise rollup in the unpruned map, which grows quadratically in players.
2. House Championship — persistent all-time leaderboard on lobby + TV #371 deliberately sent the standing only to its owner. A head-to-head on the TV broadcasts two people's record to the whole room. That is a conscious reversal of that decision, not an extension of it, and it should be decided as one.

Effort: small for the 90-day version, medium with a rollup.

From an automated ideation pass; anchors verified against the source.

[mholzi]

Design shotgun: three ways to build this — and the decision is not what the line looks like

One variant is already built and sits unmerged as #646. The open question was never the styling of the line. It is this: #371 deliberately sent the standing only to its owner. A record between two people on the TV reverses that. Not an extension of it — a reversal, and it should be decided as one.

Three variants were drawn against that.

A — TV duel · already built (#646)

The TV shows the head-to-head for the most-frequently-co-playing present pair. TV and admin only, never the phones, and only in the lobby.

• Strength: finished and tested. A test explicitly asserts that the call is not broadcast(, so it cannot silently become a room-wide send.
• Cost: reverses House Championship — persistent all-time leaderboard on lobby + TV #371. Two people's records hang on the wall for everyone.

B — Quiet duel

The record goes to the two phones, not the TV. Anna sees her standing against Ben, Ben sees his against Anna. Nobody else sees anything.

• Strength: House Championship — persistent all-time leaderboard on lobby + TV #371 stays intact — every standing still reaches only its owner, with no exception carved into it.
• Cost: the rivalry starts quietly. Two people know something the room cannot pick up on.

C — Evenings together · recommended

The TV shows the pair, but no score: how many evenings they have played together, and since when. The room starts the rivalry, not the screen.

• Strength: does not reverse House Championship — persistent all-time leaderboard on lobby + TV #371. A shared number belongs to both players; a score belongs to one and is told about the other.
• Cost: not what this issue asks for. Anyone who wanted "3–2" gets no number to brag with.

The comparison

Axis	A TV duel	B Quiet duel	C Evenings together
Who sees it	the whole room	only the two	the whole room
Reverses #371	yes	no	no
Shows a score	yes	yes	no
Starts the rivalry	immediately	quietly	through the room
State	built	not built	not built

The 90-day footnote is the smaller question

Both TV variants inherit the pruning at RETENTION_DAYS = 90 and MAX_DETAILED_RECORDS = 1000; labelled honestly that is "last 90 days", which is what #646 does. An all-time claim needs a pairwise rollup that grows quadratically in players — not proportionate for a lobby line. That applies equally to all three, so it is not an axis they differ on.

Why C

It addresses the one thing actually up for decision here. The comment at analytics.py:302 says the line is "supposed to start a rivalry" — that needs two names side by side, not their record.

And the way back stays open, which is the asymmetry that decides it: turning "5 evenings together" into "3–2" later is one line; turning a broadcast back into something private is not.

If the call is instead that #371 should fall here deliberately, A is finished and can be merged today.

Still open

C, or merge #646. Nothing further is built.