D.C. snagged the top spot on this year’s ParkScore, the Trust for Public Land’s annual ranking of urban parks and recreation opportunities in the 100 largest cities in the country.

We have been duking it out with the Twin Cities (St. Paul was second and Minneapolis was third) and neighboring Arlington, which was fourth, in the top of the ratings for several years. “They’ve all been in close competition, and that competition has gotten closer,” says Charlie McCabe, the director of the Trust’s Center for City Parks Excellence.

Criteria for the ranking include the percentage of people living within a ten-minute walk to a public park; the average size of a city’s parks, and the percentage of city land devoted to parks; the amount of money the city spends on its parks, per resident; and the availability of park “amenities,” or features like basketball hoops, dog parks, public restrooms, playgrounds, recreation and senior centers, and “splashpads,” or structures for playing in water.

So why did D.C. emerge victorious, at least this time around? In a word, amenities.

“D.C. was able to meet their goals of reinvestment in existing parks,” McCabe told DCist. “They have the maximum number of points in recreation and senior centers and splashpads, and they’re really close in basketball hoops.”

One weakness in D.C., though: it’s behind on playgrounds, at just 1.7 per 10,000 residents.

Providing those amenities matter, says McCabe, because they are a proxy for how well parks are serving a good range of kids, adults, and seniors—and therefore a wide variety of community needs. “What we want is a blend of all three of those groups being adequately served by elements of a park,” he said.

Beyond amenities, D.C. is doing well in other categories, too. The city has one of the highest investment rates, spending $270.40 per resident on its parks. That figure includes public money, nonprofit contributions, and volunteer hours. It also does well in access, measured by how many people live within a 10-minute walk to a park. In D.C.: 98 percent of residents do.

Arlington, which was fourth in the ranking last year, maintained its spot. The county adopted a new Public Spaces Master Plan last month to help guide its parks and public spaces as the population using them grows. Amazon’s arrival in Crystal City, McCabe says, is one of the issues on the horizon for the county’s parks. “It’ll be interesting to see how they respond to that,” he commented.

McCabe acknowledges that, particularly in a city like D.C. that has good public parks, the changes in its ranking from year to year “definitely could be” a matter of marginal improvements, not major strides. And he notes that the city has a long history of incorporating green spaces, going back to Pierre L’Enfant’s 1791 plan for the city.

But he says that D.C. shouldn’t rest on its laurels. The city–and its Twin Cities and Arlington competitors–is growing, and that means its parks will have to adjust to a bigger, denser population in future. “As you get more density, you get more usage,” he explains. “It’s up to the city to fund the operational maintenance to the level it needs.”