The New York Yankees are investing millions of dollars this year in a different kind of lineup at the plate: porterhouses, New York strips, rib-eyes and filet mignons. NYY Steak, the chophouse that debuted four years ago at Yankee Stadium, is opening at Rockefeller Center this summer. Amid a boom of steakhouses in the city over the past several months, the Bronx Bombers' restaurant at 7 W. 51st St. will be the most ambitious in size, at 16,000 square feet, and buzz. As beef prices continue to rise—they are expected to reach record highs this year—the addition of about 10 substantial steakhouses in the city that have either opened over the past several months or will open later this year contradict some of the grim predictions about the economy. Diners are filling the seats and show no sign of pushing back on such pricey menus. Despite a seeming glut—there are nearly 200 steakhouses listed in the five boroughs by the Zagat Survey—the operators and owners behind these myriad ventures are confident they can thrive in an increasingly crowded field. Many are banking on their brands, or on celebrity chefs like Arlington Steakhouse's Laurent Tourondel, to draw customers. Or, like Delmonico's owners, they are partnering with deep-pocketed investors to help them expand. On average, steakhouses generate between $5 million and $12 million a year in revenue, an attractive amount for investors who want to bet on food businesses with a proven formula, according to restaurant consultant Arlene Spiegel.