Thin braid digs into the spool. Especially if you're using the slick coated braids, or super thin 8 carrier braids. I prefer braid that has at least 12# diameter (keyword: diameter, not breaking strength), especially if you're really whipping lures out there. People typically try to get super distance with cranks and jerks, so that only adds fuel to the fire, because it's putting that much more load on the line. The reason it breaks was mentioned earlier, braid has relatively crappy shock strength. You can pull in a log, but if you yank it really quickly, it snaps pretty easily.