Flat-sided crankbaits catch bass all year but as Randy Blaukat states, "they're at their best during the prespawn when water temps are cold but starting to warm." Randy shares a pile of good info on when to reach for the flat side box and how to fish these baits. Bass and baitfish are usually a little sluggish during the prespawn warmup. Unlike their round-bodied cousins, flat-sided crankbaits have a more subtle presence that often outperforms more aggressive baits during this period of relatively cold water. Color can also be vitally important, with Blaukat providing some simple color selection guidance that's pertinent year-round.