uring the Magic Players Championship in September, everyone thought the deck of the tournament was and would be Shouta Yasooka's Eternal Command deck, which helped him dominate the Swiss rounds of the tournament and proceed to the finals. There he met and was defeated by Yuuya Watanabe, who, incidentally, was more or less unstoppable throughout 2012.
Ultimately, while Shouta might have had the deck for the tournament, it was Yuuya who ushered in the beginning of an era of Jund's dominance of Modern that has continued to this day. The deck has evolved significantly from its roots since the printing of Return to Ravnica, though.
The basic idea of Jund has always been to play the most versatile and efficient creatures and disruption across a smooth curve. It relies on excellent card quality and ease of exchanging cards on a one-for-one basis for very little mana, with just enough cards that need to be answered—or require two of the opponent's cards to answer—to win the game. The deck thrives on beating decks that require multiple cards to work together, since it's so good at picking apart the pieces.
Yuuya Watanabe's Jund
Modern – Winner, Magic Players Championship