Boston offers the best access to public parks for its children among seven cities studied by the Trust For Public Land, with 78% of its youngsters living within a quarter-mile of a public park. Los Angeles (34%) and San Diego (32%) were worst.
The report, No Place To Play, notes that L.A. actually offers a lot of park land per capita -- 7.9 acres per 1,000 residents -- but a few large parks far away from most-populated areas skew those results. New York offers much less park space per capita -- 4.6 acres per 1,000 -- but it's distributed much better for easy access (close to 60% of New Yorkers live within a quarter-mile of a park).
Open-space per-capita statistics don't tell the whole story about whether that space makes for a more day-to-day livable communy. Large recreational parks are indeed a great asset. But it's also important to see how accessible and usable is open space is for residents in their daily lives.
The same holds true for any kind of open-space requirement when a development project is approved. There's space that will add value to the surrounding communities, and space that doesn't do anything except make a project even less pedestrian accessible.