Gomwolf,
From the pilot perspective the gunsight / weapons aiming glass has an adjustable mil reticle. When employing manual weapons (bombs / rockets / guns) you can adjust your "gunsight" in increments called mils. With bombs in particular you have to adjust for winds and that was done in one of two ways: mil crank or combat offset. Mil cranking involved estimating how much you have to adjust the sight (so the pipper would be on the target) for your bombs to hit the target. When going to the range, you would look for smoke stacks, large flags, bodies of water to help you guess what the winds were doing. If you were in combat or a competition the flight lead would tell everyone where he put his pipper on the first pass so they could make adjustments off of that. If you reached up and dial adjusted mils, you mil cranked. If you don't mil crank, you adjust by moving your pipper in relation to the target to compensate for winds, and that is called "combat offset".
Then there are a thing called tiger errors. If you are dropping you need to be on dive angle, speed, and at the proper altitude when you pickle. If you pickle a 100' high, or fast, or shallow, the error is greater than 100' low, or slow, or steep. So what you need to walk away with is being steep, fast, and pressing will result in "smaller" errors than it's equal opposite. Steep, fast and press was the mantra for better scores.
Cheers,
Biff