Print A battle between wealthy Del Mar property owners over a literal line in the sand could go to the ballot box in November. Serial investor Rick Thompson, who made his fortune founding and growing video game companies, has drafted a citizens initiative that would change the formula used to calculate the maximum total floor area allowed in new beachfront homes. Thompson, who owns a $22 million home, one of the largest in the city’s beachfront area, says the goal of his initiative is to protect the beach for everyone. He’s also said the initiative would help avoid “mansionization,” a term often used for building large new homes on small older lots. But his critics say that idea is hypocritical because Thompson’s recently remodeled home is one of the largest mansions on the coast.