Philanthropy’s biggest crux is pretty universal: No matter how much people give to charitable causes, it won’t ever be enough. The world has a lot of problems; many needs will continue to go unmet without broader, systemic change.

For a growing contingent of so-called effective altruists, that paradox means using some math and logic to calculate what they think is the most strategic way to positively affect the most lives for the fewest dollars spent. Professional poker player Dan Smith likes that logic, so he’s sweetening the pot.

Smith, the fourth-ranked player in the world, has cleared about $20 million in winnings on the professional circuit. Between now and the end of the year, he and two other poker and fantasy sports icons, the brothers Martin and Tom Crowley, have promised to match up to $1 million in donations toward 10 cost-effective charities.

“I like the idea of reminding people that one person can make a difference,” he says in an email to Fast Company.

Like a good logician, Smith shares more about the proven success of each solution in a post on his personal blog. The first four are also some of the top picks of 2017 by charity effectiveness evaluator GiveWell, while others have been vetted by other effective-altruism researchers that share data, like Animal Charity Evaluators, and the Open Philanthropy Project.

Read the full article about pro poker player Dan Smith matching effective altruism-based donations by Ben Paynter at fastcompany.com.