You must do what this achievement says to unlock it (big surprise eh?). You must beat someone with at least 27 or more stones.
This can either be completed against the AI or against another person in a ranked match or player match.
I would highly recomment boosting with someone however if you can't find someone to boost with and want to try against the computer try this:
- Try not sending over any pieces to the other side EVEN if you plan to take them on the next turn.
- By landing in an empty pit you will take all the pieces from the container below/above it.
===Being Efficient===
It will also help your progress in (IF PLAYING ONLINE) "Winner Of Games", "Game Swap" (if other games done in same session), "Player of Games", "Mancala Warrior", and "Play 5".