Below are power ratings for all twelve Nippon Professional Baseball teams, built from this season's results and nothing else. No picks on this page, no odds, no affiliate links. The formula for turning any two of these numbers into a win probability is here as well, so you can price a matchup yourself rather than take our word for one.
A power rating answers a narrower question than the standings do. The standings tell you how a season has gone. A rating tries to tell you how good a team is right now, which is the only version of the question that helps before tomorrow's game.
| # | Team | Rating | W-L-T | Win % | Expected win % | Run diff |
|---|---|---|---|---|---|---|
| 1 | Fukuoka S. Hawks | 1732 | 91-47-3 | 0.659 | 0.697 | +257 |
| 2 | Yokohama BayStars | 1619 | 71-69-3 | 0.507 | 0.538 | +45 |
| 3 | Rakuten Gold. Eagles | 1542 | 57-84-1 | 0.404 | 0.426 | -83 |
| 4 | Nippon Ham Fighters | 1537 | 78-61-3 | 0.561 | 0.553 | +64 |
| 5 | Seibu Lions | 1531 | 78-59-4 | 0.569 | 0.538 | +40 |
| 6 | Yomiuri Giants | 1470 | 75-64-3 | 0.540 | 0.541 | +41 |
| 7 | Hiroshima Carp | 1469 | 61-78-4 | 0.439 | 0.415 | -89 |
| 8 | Hanshin Tigers | 1461 | 79-61-2 | 0.564 | 0.577 | +80 |
| 9 | Chiba Lotte Marines | 1431 | 62-77-3 | 0.446 | 0.418 | -96 |
| 10 | Chunichi Dragons | 1419 | 60-81-2 | 0.426 | 0.485 | -16 |
| 11 | Orix Buffaloes | 1414 | 64-76-2 | 0.457 | 0.396 | -124 |
| 12 | Yakult Swallows | 1375 | 61-80-2 | 0.433 | 0.394 | -119 |
1500 is the starting point every team begins the season on, so a rating above it means a team has taken points off the field and below it means it has given them away. Run differential is there because it is the single most useful sanity check on a record: a team well above .500 with a flat run differential has usually been winning close games, and close games are the least repeatable thing in baseball.
Records, run differential and expected win percentage count regular season games only, taken from our own game feed, so a record can differ by a game or two from the official table where the feed is missing a result.
This is the whole formula. There is nothing hidden behind it.
We use 25 points of home advantage for baseball, which corresponds to a home team winning about 54% of otherwise even matchups. Worked example with two illustrative ratings, a 1716 team visiting a 1538 team:
So the home side wins roughly 29% of the time, which is a fair price of about 3.41 and an implied 71% for the visitor. Compare that with the price a bookmaker is offering and you have the beginning of an opinion. Only the beginning: a rating built on results alone knows nothing about who is pitching tomorrow, and in baseball the starting pitcher is the single largest known variable before first pitch.
A rating is a prior, not a prediction. It tells you what the season says before anyone has looked at the lineup card.
The commentary in this section was written on 14 September against the table as it stood that day. The tables above and below have since been rebuilt from the final results; these paragraphs have not. Check them against the current numbers rather than assuming they still hold.
Two rows are worth pulling out. The Yokohama BayStars sit third on rating with a record barely over .500, and the Hanshin Tigers sit sixth on rating with the second best run differential in the league. Those are the two largest disagreements between our number and the table.
The BayStars case is the clean one. They were 44-53 at the start of August and 23-12 since. A rating updates game by game, so a team playing well now outranks its own season record, which is exactly what you want if you are pricing tomorrow. Their rating has moved 108 points since 1 August, the largest swing in the league in either direction.
Now the part that argues against the number we just published. Sort the same teams by the average rating of the opponents they have actually faced.
| Team | Rating | Average opponent | Record vs top tier |
|---|---|---|---|
| Yokohama BayStars | 1619 | 1450 | 1-2 |
| Hiroshima Carp | 1469 | 1477 | 9-17 |
| Yomiuri Giants | 1470 | 1477 | 14-14 |
| Hanshin Tigers | 1461 | 1478 | 13-15 |
| Chunichi Dragons | 1419 | 1485 | 8-19 |
| Fukuoka S. Hawks | 1732 | 1487 | 2-1 |
| Yakult Swallows | 1375 | 1493 | 15-13 |
| Rakuten Gold. Eagles | 1542 | 1520 | 13-14 |
| Seibu Lions | 1531 | 1523 | 12-15 |
| Nippon Ham Fighters | 1537 | 1523 | 8-18 |
| Chiba Lotte Marines | 1431 | 1541 | 9-18 |
| Orix Buffaloes | 1414 | 1544 | 12-16 |
As of 14 September the BayStars had the weakest schedule in the league by this measure, and against the teams rated 1550 or better they were 2-7. So the surge that moved them into third came largely against the part of the league that is not very good, and the rating has not discounted it as hard as we think it should.
One apparent contradiction worth naming, because the table above invites it. The expected win percentage column says the BayStars have been unlucky, not lucky: their runs say .541 against an actual .508. That column knows nothing about who they played. Strength of schedule and expected win percentage answer different questions, and here they point in opposite directions, which is the honest state of the row rather than a problem to be resolved in our favour.
We are saying this about our own output because a rating you cannot catch being wrong is not worth much. If you use the ratings above, use the schedule column next to them. A number built on a soft month is a weaker number than the same figure built against the top of the table, and nothing in a single rating column tells you which one you are looking at.
Since this is a betting site, the fair question is whether any of it pays. Most of our NPB bets are totals. The rest are moneylines in ones and twos per team, which is not a sample anyone should reason from.
Some honest context. One league's slice of a few dozen bets is not enough to prove a thing. It turns into noise in either direction over a month, which is why the live numbers sit on a public record that we do not edit rather than in a headline.
Worth one more line, because it shapes every totals line in this league: NPB is a low scoring environment. The average combined runs per game is in the header of this page, and it runs roughly three runs below the Korean league. A totals number that looks low next to a KBO game is usually just Japanese baseball.