In culinary terms, score means to cut slits on the surface of a piece of food. The most common uses of scoring include small uniform cuts in pieces of raw meat and the deeper slashes that decorate the top of bread loves while letting steam escape.
For meat, the knife blade should penetrate only about 1/8 to 1/4 inch deep. In general, score marks should be spaced approximately 1 inch apart. From there, you can add a crosshatch pattern, insert chopped aromatics such as garlic or ginger into the cut meat, or press a dry seasoning rub into the little pockets.
Why Score Meat
Scoring meat before you cook it results in a greater surface area exposed to the heat, leading to more even cooking and encouraging the Maillard reaction. This chemical reaction occurs during cooking and is what leads to an appealing browned crust. With tougher cuts of steak such as flank, scoring the meat severs the long fibers that make it harder to chew. This type of scoring is more for ease of eating rather than just appearances.
Fattier cuts of meat such as duck benefit from scoring, which allows excess fat to drain. Scoring also makes it easier for meats to absorb marinades. With whole fish, deep scores down to the bone allow heat to quickly reach the center flesh, reducing the likelihood of an overcooked exterior and undercooked interior. Scoring skin-on fish fillets keep them from curling; a few minutes in the freezer makes it easier to control the depth of your cuts for softer fish such as sole. A spiral-cut ham, sometimes marketed as a holiday ham or a city ham, displays a more extreme example of scoring, which cuts the meat through to the bone for easier serving.
What Type of Knife to Use
The most important part of scoring is to use a sharp knife when you score meat. This will result in a clean cut; dull knives, besides being dangerous, leave ragged edges. You don't want a serrated knife, just a clean, sharp knife. Start with a diagonal cut pattern across the length of the meat. Space the scores evenly across to ensure a proper look and cooking. Then turn the meat 90 degrees to add a crosshatch to each of the previous scores. You can score the meat on both sides.
Scoring Inexpensive Cuts of Meat
One cooking hack is to score more inexpensive cuts of meat like flank or hanger steak prior to grilling. While it won't magically transform these cuts into filet mignon, scoring other cuts of meat will likely make the meat more tender and will allow any spice rubs or seasonings to penetrate better. For an easy taste test, compare two of the same cuts. Season and cook them the same way, with one piece scored prior to cooking and one left as-is.