When there is a lot of bait in the water, a louder and faster retrieve may be more productive. These are like plugs, but unlike plugs they dive, vibrate and wobble. Easier to use than jigs, cranks are a great tool to locate bass and lure them out of weeds and structure. Cranks are designed to run at certain depths. It is important to keep an assortment of cranks that will run at different depths in your tacklebox.
Depth is very important.
Moderate retrieve will maximize the cranks depth. A fast retrieve will keep the crank near the surface. In clear water, a fast retrieve is better as the bass can see further. In murky, water a slower retrieve is better to maximize sound and vibration to allow the bass to locate the lure. Remember to always cast further than your target to allow your crank to dive to the right depth.