Cab or merlot—vino version of “Ginger or Mary Ann?”

Cabernet sauvignon and merlot are America’s most popular red wines. Each has its own set of characteristics. Differences not only fuel debate about which is best, differences complement each other—which is why Bordeaux blends (usually with help from other grapes, especially cabernet franc) rank among the world’s greatest wines.

Both cabernet sauvignon and merlot developed in Bordeaux, a region in southwest France divided by the Gironde Estuary. In broad terms, people on left bank (western side) believe their more gravely soil is copasetic for cab. People on right bank (eastern side) claim their clay soil is marvelous for merlot.

Bordeaux wines blend both. If you crave cab, ask for a left bank bottle, where cab predominates. If merlot moves you, request a right bank effort, where merlot predominates.

Cabernet is more tannic than merlot. It is often described as having “backbone,” which means it is hearty, powerful, and has good acidity. Flavor descriptors include black cherry, blackcurrant, and olives. Cabs are extremely age-worthy; many quality cabs demand age in bottle to achieve their best. Ginger.

Merlot is noticeably softer and fleshier. It often is described as juicy and “easy drinking” with flavors of cherry and chocolate. Its softness causes it to taste good at a much younger age than cab. Mary Ann.

You decide which grape you enjoy, or get the best of both with a blend. Many New World makers blend in Bordeaux style, and many bottles labeled cabernet sauvignon have up to 25 percent of other grapes—often merlot—blended to round out the flavor.

If foolishly forced to choose, I prefer cab and Mary Ann, splitting the difference.

Tasting notes:

• Château Fleur de Lisse Saint-Emilion Cuvée Minvielle 2011: Right bank Bordeaux with classic characteristics, superb price, 70% merlot, but decant to tame the 30% cab franc. $22

• Château Calon-Ségur Marquis de Calon Saint-Estèphe 2009: Serious wine, very approachable introduction to great wines of the left bank. $42

• Trione Block Twenty-One Cabernet Sauvignon 2009: Must-taste effort for lovers of big, powerful Alexander Valley Bordeaux blend cabs. $65-76

Last round: Keep friends close, enemies closer, fine wine closest.