What was the margin of victory when the winning score was –10 (70-72-68-68=278)?
CREATE TABLE "pga_tour_wins_11" (
  "date" text,
  "tournament" text,
  "winning_score" text,
  "margin_of_victory" text,
  "runner_s_up" text
);
SELECT "margin_of_victory" FROM "pga_tour_wins_11" WHERE "winning_score"='–10 (70-72-68-68=278)';