Published ballot odds vary widely: Sydney ~33%, Chicago ~25%, Berlin ~20%, Tokyo ~10%, London ~1.3%, New York City ~1%. Boston has no lottery, it is qualifier-only. Cape Town's first ballot odds have not been published yet.
Yes. Each Major runs its own ballot on its own schedule, so there is nothing stopping you entering several in the same year. This calculator adds up your combined chance of at least one acceptance across every ballot you tick.
Entry fees are only charged if you are drawn, and they run in each race's own currency: for example Tokyo charges in yen, London and Berlin in pounds and euros, Chicago and New York in US dollars, Sydney in Australian dollars. The calculator totals your at-risk fees grouped by currency for the ballots you tick, since converting across currencies would need an assumed exchange rate.
Yes, and that is a simplification, not a guarantee. Each Major draws its ballot from its own applicant pool with no published link between results, so treating them as statistically independent is the standard way to combine odds. It cannot capture any real-world correlation, such as ballots that skew toward the same pool of serious repeat applicants.
Yes. Several Majors open and close their ballots within weeks of each other, and some draw results in the same week. The calculator flags any overlap or same-week draw date between the ballots you tick, using each race's currently published window.
Boston is the only Abbott World Marathon Major that is qualifier-only, there is no random ballot or lottery to model. Its non-qualifying route is a charity bib with a fundraising minimum, a guaranteed path rather than a probability.