About This Site

What this site is

Yakyu Toolsis an unofficial fan site for following the NPB (Nippon Professional Baseball) pennant race. Every day we automatically recalculate each team's magic number, whether the pennant is still in its own hands, and its Climax Series clinch and elimination scenarios — and every team page includes a what-if simulator for upcoming games.

Data source

Standings and results are independently compiled and calculated from game results and standings published on the official NPB website. This site is not affiliated with NPB or any of its clubs, and does not use player or club photographs, logos, or other protected materials.

Calculation method and disclaimer

• Magic numbers are computed as the number of wins that guarantees first place regardless of other teams' results, accounting for remaining head-to-head games and the effect of tie games.
• Tiebreaker rules for identical winning percentages are deliberately not applied: while a tie remains possible we do not declare anything "clinched" — a conservative approach.
• We take great care with accuracy but cannot guarantee the content. Always check official NPB and media announcements for confirmed results.

Updates

Standings, magic numbers, and Climax Series scenarios are recalculated automatically every day from the official published results. Daily ranks and games-behind are also recorded so season-long charts can be shown on team pages. Late-night and early-morning visits may briefly show the previous day's results.

Operator

This site is run by an independent developer under the trade name "Aratan Works" (launched July 2026), who also operates the Japanese-language version of this site. Corrections and feedback are welcome at takaiwashin.dev@gmail.com or via the contact page.