Can I make a ballpark, a hockey or basketball arena, or a soccer stadium?

Yes. The library has shelves for MLB (all 30 ballparks), the NHL (32 arenas), the NBA (30 arenas) and MLS (the soccer stadiums, plus the NFL stadiums an MLS team shares). A ballpark gets its real diamond: home plate where it is, the 90-foot bases, the mound, the infield dirt, the foul lines, the warning track and the outfield wall in the park's own shape (the Green Monster, Wrigley's bleachers), with home plate at the bottom of the board. An arena gets a 200 by 85 foot hockey rink (red and blue lines, faceoff circles, creases) or a 94 by 50 foot basketball court (keys, arcs, centre circle), and an arena two teams share lets you pick the team: the floor follows it. A soccer stadium gets a 105 by 68 m pitch. Every mark can be switched off under Details. Arena roofs hide the floor, so a rink or court follows the building's long axis; the few nearly-round arenas where that may be a quarter turn out are marked in the library.