There are a lot of factors that go into greatness, many of which are not obvious. A variety of Olympic and professional athletes tell us how they made it and what they sacrificed to get there. And if you can identify the sport most likely to get a kid into a top college — well then, touché! (Ep. 3 of “The Hidden Side of Sports” series.)

Stephen Dubner’s conversations with members of the San Francisco 49ers offense, recorded for Freakonomics Radio episode No. 350, part of the “Hidden Side of Sports” series.

The San Francisco 49ers, one of the most valuable sports franchises in the world, also used to be one of the best. But they’ve been losing lately — a lot — and one of their players launched a controversy by taking a knee during the national anthem. So why is everyone there so optimistic? To find out, we speak with the team’s owner, head coach, general manager, and star players, including their new $137.5 million quarterback. (Ep. 2 of “The Hidden Side of Sports” series.)

Dollar-wise, the sports industry is surprisingly small, about the same size as the cardboard-box industry. So why does it make so much noise? Because it reflects — and often amplifies — just about every political, economic, and social issue of the day. Introducing a new series, “The Hidden Side of Sports.”

We all know the standard story: our economy would be more dynamic if only the government would get out of the way. The economist Mariana Mazzucato says we’ve got that story backward. She argues that the government, by funding so much early-stage research, is hugely responsible for big successes in tech, pharma, energy, and more. But the government also does a terrible job in claiming credit — and, more important, getting a return on its investment.

Kenji Lopez-Alt became a rock star of the food world by bringing science into the kitchen in a way that everyday cooks can appreciate. Then he dared to start his own restaurant — and discovered problems that even science can’t solve.

The environmentalists say we’re doomed if we don’t drastically reduce consumption. The technologists say that human ingenuity can solve just about any problem. A debate that’s been around for decades has become a shouting match. Is anyone right?

The U.N.’s World Happiness Report — created to curtail our unhealthy obsession with G.D.P. — is dominated every year by the Nordic countries. We head to Denmark to learn the secrets of this happiness epidemic (and to see if we should steal them).

After every mass shooting or terrorist attack, victims and survivors receive a huge outpouring of support — including a massive pool of compensation money. How should that money be allocated? We speak with the man who’s done that job after many tragedies, including 9/11. The hard part, it turns out, isn’t attaching a dollar figure to each victim; the hard part is acknowledging that dollars can’t heal the pain.

One of the world’s biggest and best-known companies just announced that its C.E.O. would be stepping down in the fall. We interviewed her as part of our series “The Secret Life of a C.E.O.,” and we thought you might like to hear that episode again, or for the first time if you missed it back then.