While on vacation several years ago, Matt Piacentini, owner of New York’s The Up & Up, got behind the home bar setup, a bottle of sherry in hand, ready to serve a thirsty crowd of friends. “Making Sherry Cobblers for 20 people became difficult after the first round,” he recalls. So he switched to drinks that were easier to batch: Manhattans and Martinis, also made with a portion of his beloved sherry, in addition to vermouth. “That’s when I realized, this really works!”

By splitting the vermouth component with the Spanish fortified wine, Piacentini riffs on the “perfect” cocktail construction, a build he embraces for its ability to add complex flavor without veering too far from the classic blueprint. A “perfect” cocktail traditionally divides the vermouth component in, say, a Martini or Manhattan, into equal parts dry and sweet, but the formula leaves room for experimentation. “It’s infinitely variable and almost always reliable,” says Piacentini. “That’s why I love the construct.”

The ever-broadening market of wine-based modifiers—vermouths, quinquinas like Cocchi Americano or Byrrh, or even wine-based “vino amaros” like Cardamaro—only makes the perfect construction even more appealing, as bartenders take the build in unexpected directions.

That approach results in nuanced drinks with personality that still bear strong resemblance to their classic counterparts. Consider The New New Steady by Tom Martinez for Washington, D.C.’s Columbia Room. The recipe balances dry vermouth and Cocchi Americano alongside coconut-washed gin for a tropical-accented take on a Perfect Martini. Piacentini, meanwhile, often uses the perfect construction to “lighten” drinks where he finds sweet vermouth alone a bit cloying. “The Manhattan is a great drink, but by the end it’s a little much,” he says. In his oloroso-spiked Perfect Manhattan, the typical richness and dark fruit of sweet vermouth is balanced by the mild, nutty tones of the sherry.

The Rob Roy is another popular perfect. Typically, the cocktail is a straightforward, Manhattan-like mix of Scotch and sweet vermouth, but, according to Vince Bright, “the story is never fully told when you have one ounce of sweet [vermouth] only.” His solution is the House No. 3: a Perfect Rob Roy that not only splits the vermouth component with sherry, but further splits each of those elements between dry and blanc vermouths and amontillado and manzanilla sherries. “The split of a dry/sweet is necessary to grab some of the more floral and botanical elements from the Scotch whisky,” says Bright.

It’s for this reason that Joaquín Simó spotlights a Perfect Rob Roy as one of his favorite drinks, noting that “the split between the dry and sweet vermouth ... really lets mellow whiskies still shine.”

In fact, most perfect cocktails are variations on austere, stirred-style drinks, designed to soften their bracing quality. Splitting the vermouth component makes them a bit more forgiving, which in turn makes room for other flavors. Case in point: Ivy Mix’s Perfect BQE. It starts as a straightforward Perfect Manhattan—rye plus a half-ounce each of sweet and dry vermouths—but, in the style of “improved” cocktails, which see the addition of liqueurs to pared-down builds, she adds small amounts of green Chartreuse and maraschino liqueur for an herbal lilt. Admittedly, it seems counterintuitive that a “perfect” cocktail could be “improved,” but don’t let semantics stand in the way of a good drink.