As usual, Thanksgiving box office was ripe with specialty players looking to offer alternatives to family fare — and the indies delivered effective counterprogramming.Leading the specialty charge, Fox Searchlight’s “The Descendants” landed in the top 10 for a second straight week, grossing $9.4 million over the long holiday weekend. The film pushed past the $10 million mark in just 12 days, making it Searchlight’s fastest-grossing film to reach that benchmark. Last year, “Black Swan” reached $10 million after 17 days; pic then cumed a boffo $107 million domestically. “Descendants” benefited from a healthy expansion plan, broadening to 390 theaters (up from 29) the day before Thanksgiving, with an additional 43 locations added two days later. But thanks to a far more limited rollout at four playdates, the Weinstein Co.’s silent film “The Artist” scored the weekend’s best per-screen average — and the year’s third-best overall for a traditional release — with $51,220. So far, Weinstein plans to wait until Christmas before expanding the screen count. The distrib will commit to a similar patient release strategy for “My Week With Marilyn,” which also opened over Thanksgiving weekend — but at a considerably more aggressive 244 engagements. “Marilyn” tallied an impressive $2.1 million in five days.