Close races, of course, get the most money. But even long shots and good bets get a dollar from time to time.

We take FiveThirtyEight’s House and Senate forecasts and use them to compute how much candidates should get relative to each other.

A candidate with a 50% chance of winning gets approximately:

- Twice as much as candidate with a 15% or 85% chance of winning.
- Five times as much as a candidate with a 5% or 95% chance of winning.

Because ActBlue requires a minimum donation of $1 per candidate, if the calculated amount is below $1.00 we round it up or down randomly. Half the time, $0.50 becomes $1.00. Half the time it becomes nothing.

You can read detailed answers to common questions on our About page.