Combine ketchup, water, vinegar, Worcestershire sauce, brown sugar, salt, paprika, chili powder, and pepper in a medium saucepan. Bring to a boil. Reduce heat to low; simmer, stirring occasionally, until slightly thickened, about 5 minutes. Set aside 1/2 of the sauce for serving.

Preheat the oven broiler. Place an oven rack 4 inches from heat.

Brush both sides of chops with sauce, then place on a broiling pan rack.

Broil chops for 4 minutes on each side. Brush with more sauce. Continue broiling, turning and basting every 3 to 4 minutes, until juices run clear. An instant-read thermometer inserted into the center should read at least 145 degrees F (63 degrees C).