All right, it may be the only real rooftop bar in the East Bay. And the roof isn’t that high up — there’s not even much of a view. But that doesn’t take away from its grandeur. Mad Oak, which opened in downtown Oakland this summer, is sprawling. Downstairs, there’s a game room and a full bar, plus a patio area with another bar. Then there’s the upstairs roof deck in all its sunlit splendor. The space quickly proved its capacity when it was packed railing to railing with Warriors fans during the NBA championships in June. It not only boasts multiple mounted televisions, but a projector for turning the wall facing the deck into yet another sports-watching platform. Being packed around a television with a huge group of strangers is substantially more enjoyable in fresh air. The Mad Oak roof is the perfect place to spend a summer evening, taking advantage of the generous overlap of hours during which the sun is shining — and it’s socially acceptable to drink. But the spot will likely be packed all year long, because beer is always better on a roof.