You can buy the best-looking ground beef your supermarket sells, gently hand-form it into patties, season it perfectly and cook it over your grill's highest heat and it still doesn't come close to the best hamburgers at top restaurants.

And why is that, you ask?

What you're missing is the mix.

Rather than using a single cut such as chuck, sirloin or top round, serious burger purveyors and -- these days -- chefs at the best restaurants are using a combination of beef cuts to create hamburgers that stand out from the competition's.

By mixing sirloin, top round, short rib, flank and other cuts, they create blends with more complex, distinctive flavors and better mouth-feel than any single cut could yield alone.

Mark Brown, co-owner of the venerable Red Coat Tavern in Royal Oak, Mich., has employed the technique for a number of years, he says. "I use a proprietary blend of different cuts ... and I just tweaked it again. It provides more steak flavor than just ground meat."

Home grillers couldn't duplicate his blend, he says. Besides containing different cuts, it's made with two grinds and both choice and prime meats. "It's a complex thing. If you're doing 10 burgers at home, it's almost impossible to do."

Creating an ideal mix of cuts "sounds so easy, but there's a real science to blending it," he says.

Someone else who understands that difficulty is Gene Baratta, president and CEO of Fairway Packing Co., meat supplier to many of the region's best restaurants.

"If you don't get those particular components in the right percentage, it throws off the whole profile of the hamburger. It could be too greasy or too rich," especially if it has too much short rib or brisket, said Baratta, whose company is in Detroit's Eastern Market.

Chefs from some top local venues asked him to help them develop their own custom blends -- a hallmark of high-profile New York hamburger meccas such as Shake Shack, BLT Burger and the Spotted Pig.

"Usually I'll tell them, 'I understand what you want, but it's not that easy.' ... You have to come up with the right-tasting mixture, so it will cook properly," he says.

So six months ago, after extensive research, Fairway introduced its own premium product called Chop House Blend. "It's a combination of fresh brisket, boneless short rib, our bench trimmings and chuck," he said. He's now supplying it to about 15 Detroit-area restaurants as well as others across the country.

"It's the best I've ever tasted. I'm a little prejudiced," he admits, "but it's really a good, good hamburger."

Because it's more expensive, the restaurants have to price the hamburgers at $10-$12 each, compared with the area's average $7-$8 for what Baratta considers a good burger.

Despite the difficulty of doing so, some restaurants grind and blend their own beef in-house.

One is the Westin Book Cadillac's stylish Roast, whose juicy burger has many fans. It's made with a blend of cuts plus the trimmings from the steaks and chops, says sous chef Norman Valenti. He prefers sirloin or chuck for great flavor and mouth-feel, but to him the key is "the freshness of the meat. ... It's the No. 1 thing."

Blending meat is merely the latest way in which chefs are trying to improve their food and please guests, says Benjamin Meyer, executive chef at Quattro Pizzeria & Wine Bar in Birmingham, Mich.