Why not lvl 49?
MMLD (Modified Mid Level Dueling) is a different take on the classic MLD (level 49) that creates some significant differences with the inclusion of several new runewords, along with providing additional skill points. These changes open up several new builds (e.g., WW Sin) and rebalances melee vs. caster with the addition of items like Fortitude and Death. In addition, items available at level 59 tend to be more easily obtained than many of the rare/magical items necessary at level 49. The overall goal is to remove barriers to entry and promote build diversity.
Some Key runewords level 59 allows include: Call to Arms, Chaos, Death, Exile, Fortitude, Heart of the Oak, King Slayer, Silence. Note: Grief is prohibited.
The goal of this group is in no way to compete with traditional MLD leagues nor claim that it's better. It's simply different. Also, as a new group, rules will continue to evolve as we grow

Definitely the ladder with the most active group right now.