Ireland vs Japan
What the model says about this fixture, at either ground and at a neutral one, with the record behind it. Ratings as at 2026-08-23.
Ireland 94.6%4.4% JapanJapan 8.7%90.3% IrelandIreland 92.5%6.5% JapanEach figure is 5,000 simulations of this fixture. The score is where those runs are centred, not a likely scoreline — a rugby result is spread far too widely for any single one to be likely.
How the runs finished
Winning margin across 5,000 simulations of this fixture. Bars right of the centre are Ireland wins; the faded bars at each end hold everything beyond 75 points.
Margin percentiles
Eight runs in ten finished between 2 Ireland and 48 Ireland, with the middle run at 19 Ireland.
Those are gaps rather than scorelines. How much scoring the match produces is drawn separately — between 32 and 76 points in eight runs out of ten — so one bar covers many scores. The middle run above is 30-11 on a tight afternoon and 42-23 on an open one.
Why Ireland are favoured
Starting from an even match and adding what the model reads, in percentage points of win probability. Positive favours Ireland, negative favours Japan.
Ireland 1884, Japan 1310 — 574 points, favouring Ireland
Ireland are at home
Recent results, head-to-head record and rest days, as the XGBoost heads weigh them. Deliberately capped, so it can nudge the rating but never overrule it.
Head to head
Ireland8–0–1Japan9 meetings, 1991 to 2026 · Ireland by 21.2 on average
| Date | Match | Competition | Venue |
|---|---|---|---|
| 2026-07-11 | Japan 20–36 Ireland | Nations Championship | McDonald Jones Stadium |
| 2025-11-08 | Ireland 41–10 Japan | — | Aviva Stadium |
| 2021-11-06 | Ireland 60–5 Japan | — | Aviva Stadium |
| 2021-07-03 | Ireland 39–31 Japan | — | Aviva Stadium |
| 2019-09-28 | Japan 19–12 Ireland | Rugby World Cup | Shizuoka Stadium Ecopa |
The 5 most recent meetings; the record above covers all 9. A dash under Competition means the record does not name one, which is common — most rows on file carry no competition. None of this feeds the forecast: both ratings already contain these results.