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How accurate are the Japan - J1 League odds?

The closing prices of 1,841 finished games since Sat 3 Jul 2021, set against what happened: the chance the market gave, with the bookmakers' margin removed, next to how often it came in. A record of what the market did, not a tip.

The market's record

1,841 games, 2 bookmakers
  • Closing favourite won 47% 857 of 1,841 games
  • Market Brier score 0.625 0 is perfect; a coin flip scores 0.667
  • Average closing payout 93.4% 100% minus the bookmakers' margin
  • Games covered 1,841 Sat 3 Jul 2021 to Sun 11 Oct 2026

2 of the 1,843 games finished in that time are left out: no bookmaker had a closing price on every outcome.

Market chance against what happened

10-20% chance: happened 14.7% of 306 selections 20-30% chance: happened 26.3% of 2,356 selections 30-40% chance: happened 32.9% of 1,549 selections 40-50% chance: happened 45.3% of 811 selections 50-60% chance: happened 56.1% of 371 selections 60-70% chance: happened 70.6% of 109 selections 100% 0%
Market said 0%100%
Happened
Market chancePriceSelectionsMarket saidHappenedDiff
10-20% 5.00 to 10.00 306 16.9% 14.7% -2.2 pts
20-30% 3.33 to 5.00 2,356 26.3% 26.3% 0.0 pts
30-40% 2.50 to 3.33 1,549 34.0% 32.9% -1.1 pts
40-50% 2.00 to 2.50 811 44.5% 45.3% +0.8 pts
50-60% 1.67 to 2.00 371 54.3% 56.1% +1.8 pts
60-70% 1.43 to 1.67 109 63.7% 70.6% +6.9 pts

Every priced outcome of every game is one selection. "Market said" is the bookmakers' average implied probability with the margin removed; "Happened" is how often that outcome came in. On the diagonal the market was right on average; above it, that kind of result happened more often than the prices said. Bands with fewer than 30 selections are left out.

Home, draw and away

OutcomeMarket saidHappenedDiff
Home win 39.8% 41.1% +1.3 pts
Draw 27.6% 26.9% -0.7 pts
Away win 32.6% 32.0% -0.6 pts

The market's average closing chance for each outcome over all 1,841 games against the share of games it won, settled on the regular-time score. "Home" is the first-named side.

Bookmaker accuracy

lower is better
BookmakerGamesBrier scorevs market averagePayout
Unibet 1,339 0.624 -0.001 92.3%
Bet365 1,817 0.626 +0.001 94.0%

Each bookmaker's own closing prices, margin removed, scored against the results of the games it priced; "vs market average" compares it with the bookmakers' average on the same games, so a negative figure means its prices were the closer. Bookmakers with fewer than 50 priced games are left out. Differences of a few thousandths are noise; a much higher score usually means the bookmaker's last price was captured well before the start, so it is the price in our archive being scored, not the trader.

Odds accuracy FAQ

How accurate are Japan J1 League odds?
Across 1,841 finished Japan J1 League games since 2021, the closing favourite won 47% of the time. The market's closing chance, with the bookmakers' margin removed, gave the home side 39.8% on average and home wins happened 41.1% of the time. The bands above show the same comparison price by price: a well-calibrated market has outcomes happening about as often as its prices say.
What is a Brier score?
The squared distance between the chances a bookmaker's prices gave and what happened, averaged over games: 0 would be perfect foresight, and on a three-way market a coin-flip price scores 0.667. The market average's closing prices score 0.625 in this league; the lowest single bookmaker is Unibet at 0.624. Differences of a few thousandths between bookmakers are noise, not skill.
Does a well-calibrated market mean the odds cannot be beaten?
Calibration says the market is right on average, not on every game. A band where outcomes happened more often than the prices said is where the closing market under-priced that kind of result over these seasons, which is often the draw or the outsider. The bookmaker's margin, about 6.6% here, still has to be cleared: the closing line value calculator shows what a price needs to beat.

See the league's fixtures, results and the favourites' recent record on the Japan - J1 League page, every game behind these figures in the Japan - J1 League results and closing odds by season, or work out a price's implied chance and closing line value with the betting calculators.