Text: Mormon’s marking the 244th year breaks his previous pattern. Presumably, an actual historical event would have justified such a departure from the pattern, but he records only a generality: “The more wicked part of the people did wax strong.” This is more non-information. But in Mesoamerica, four was an important number; so was twenty. (See Helaman, Part 1: Context, Chapter 4, “The Meaning of Numbers: Counts and Estimates in the Book of Mormon.”) Thus two twenty’s and four was a meaningful “round” number—and that, I argue, is the only reason for this verse in the narrative.
Chronology: Two hundred and forty four years in the Nephite count corresponds to A.D. 238. Two hundred fifty is A.D. 244, and 260 is A.D. 253.