"That's NOT a calzone," repeated our adamant Why Not the Best calzone tasters.

"In New York, they deep fry them," one insisted.

"In Italy, they're dough rectangles stuffed with fontina and ham," declared another.

"In California, it's a zip code," offered another.

We left ehm all to their conflicting versions of this folded pizza and simple redefined our task: investigating calzone, Washington style.

None of them were fried, but they came in many guises, shaped like a bomb or flat as a pancake; big enough for four, small enough for one. Mozzarella, ricotta, provolone and ham were the standard fillings. Sausage mushrooms and green pepper were often added, or occasionally even anchovies, tuna fish or shrimp. Tomato sauce came inside, outside, alongside.

No wonder the definition of calzone is controversial; even its origin has several versions. According to food historian Giuliano Buglialli, the calzone was a spin-off from the spanish empanada. Italians copied the idea from Spaniards living in 19th-century Naples, substituting their pizza dough for the empanada's thinner rolled crust and folding it over ingredients more close at hand: anchovies and black olives.

Fio Vasaio of Fio's restaurant, suggests this tale for the birth of the calzone: Bakers in Italy wanted to test their stone hearths to see if they were hot enough to bake bread. They shoved in extra dough to check how quickly it would cook; then, realizing this was a waste, they began to stuff the dough with leftovers, maybe prosciutto and cheese.

Whichever way it came about, we are certain that, like the hackneyed pizza, there is no such thing as a "purist's calzone." So we had to judge each on its own merits. WASHINGTON'S BEST

Stromboli, 7023 Wisconsin Ave., Bethesda. 986-1980. $2.75. Plump, pretty, stuffed with lots of mozzarella, ricotta, flecks of parsley, some ham. Thin, crusty dough. Looks and taste would make an Italian momma jealous.

I Street Eatery, 1411 K St. NW. 347-7001. $1.89. Generous filling of mozzarella, ricotta and mediocre ham. Good crust, thicker than Stromboli's. The only calzone that drew us back for seconds; the only restaurant that had run out of calzone.

Nicola, 8 N. First St., Rehoboth, Del. (302) 227-6211. $2.40. Called a "nic-o-boli." Ground beef, sauce and provolone nicely blended. Tastes like a rolled-over pizza. Sloppy, fun beach food, addictive. Worth a visit this summer, if you haven't been there already. GOOD

That's Amore, 11323 Georgia Ave., Wheaton. 949-0650. $3.75-small; $5-large. Mozzarella, provolone, ricotta, green pepper, pepperoni or sausage, tomato sauce on the side. Slightly greasy. Thick, bready dough. Not bad, but the gyros are better.

Mamma Lucia, (in the Connecticut Connection), 1110 Connecticut Ave. NW. 466-3558. $2.35. Mozzarella, ricotta, provolone, ham. Only cheese we tasted was the ricotta -- light and sweet. Would be better if cooked longer (dough was pasty) and more seasoning added.

Pizza Deli, 146 W. Maple St., Vienna. 938-0800. $2.75. Called "stuffed pizza." Mozzarella was hard to find, but the mushrooms, green pepper, pepperoni and sausage weren't. Good crunchy crust.

Three Brothers, 6160 Greenbelt Rd., Greenbelt. 474-5330. $2.50 for ham, salami, sausage or meatball. One of the best doughs we found. Lots of ricotta. Flavor dull, could use more oomph. OKAY

Alfredo's, (in the Esplanade Mall), 1990 K St. NW. 659-9092. Creamy mozzarella, but a little on the soapy side. Pockets of saltiness, chewy dough. Would have possibilities with additional spices.

Zim's Inn, 216 N. Frederick Ave., Gaithersburg Plaza Shopping Center, Gaithersburg. 977-3030. $6.15 for cheese, $7.15 for meat and cheese. Two to three servings. Ambitious, but watery dough and ricotta, mozarella and provolone. As big as a pizza. Plain is better. Advantage of this calzone is plenty of sauce (leftovers for spaghetti dinner).

Vaccaro's, 747 4th St. NW.347-6668. $2.95. Two servings. Spice overkill; good if you like salt and red pepper. Onions, ground sausage, mozzarella, green pepper in pot pie-like crust. Similar to sausage quiche without the eggs. VERY DISAPPOINTING

Caffe Sicilia, 130 Branch Rd., Vienna. 938-3457. $2.25. Ham and mozzarella in a spongy, soggy dough.

Zio's, 9083 Gaither Rd., Gaithersburg. 977-6300. $2.50. Too much dough; uncooked and tough. Ham, sausage, onions, fennel and mozzarella filling mixed with too much oil makes a very greasy calzone. Best to ignore tomato sauce.

Zebra Room, 3238 Wisconsin Ave. NW. 362-8307. $3.00, 50 cents for each additional filling. Ricotta and provolone with your choice of numerous pizza fillings. Couldn't find provolone. Other extras are sparse too. Rubbery dough; filling, really filling.