In some situations a big bait or lure is the only way to go. The trick is knowing when to break out the big lures and leave the small stuff in the tackle box. While many different situations may call for a big lure or bait, here are a few very key ones.
1. Schools of large baitfish are the predominant forage in a given area. No sense in throwing a crappie jig when the fish are eating 10" mullet.
2. A weather change is coming, especially a large front. Ahead of a front fish want a large meal. With a full belly they can lazily lay around and wait for the weather to improve.
3. Lastly(though not always the case)..."Big Bait, BIG FISH." Big fish are lazy, they don't want to move much so eating once is better than eating ten times a day. Fishing a large bait slowly in the area of big fish won't ensure a bite; but the bite that comes is usually a BIG one!