Shogi

This post is all about chess and chess variants. I make no apologies, and my feelings won't be hurt if you skip this entry. You have been warned.

Long ago, I played Shogi once with my friend Alex back in Tucson. I have no real memories of my impressions from that game, but clearly it didn't catch my attention. However, I was re-introduced to Japan's principal version of chess last weekend, and I must say the game is fascinating. Shogi is played on a 9 x 9 board, but the goal is the same as in Chess -- to checkmate your opponent's king. In many ways however, Shogi is completely different.

The principal difference is that when you capture a piece belonging to your opponent, it becomes your own. It is removed from the board. However, on any later turn, instead of moving a piece on the board, you may drop a captured piece into any vacant square. This is exactly analogous to the situation in a popular four-person chess variant called Bughouse or Skittles. Bughouse is very fun, but suffers from the difficulty of finding four players. Shogi cuts four down to two. Hooray!

Now, Bughouse is fantastic, but it has other weaknesses, too, and Shogi seems to have an answer for them all. In Bughouse, a typical strategy is to capture several strong pieces, and then look for mate in the form of drop-checks. That is, once your opponent's king is exposed, you drop a piece to attack it, forcing your opponent's response. Then, you drop-check another, and another, and another, until you have constructed a highly effective (if not elegant) checkmate using three rooks, two bishops, a knight, three pawns, and a queen. The flaw, then, is that drop-check induced checkmate is on some level too easy to accomplish. (Let me be clear. This flaw does not stop me from playing or enjoying bughouse. But I think most bughouse players would agree the challenge would be more interesting if such checkmates were more difficult to find.)

Shogi does a much better job of balancing drop-checks. First of all, the individual pieces in Shogi have less power than their chess counterparts. There is no queen in Shogi, and you start a game with only one rook and one bishop. Therefore, amassing a strong drop-check arsenal is much more difficult.

Second, in Shogi, paws only capture straight ahead instead of diagonally. This may not seem like a big deal, but it makes openings in Shogi more robust. There is only one opening in Bughouse: White attacks f7 relentlessly, while Black defends f7 long enough to mount an attack of his own. If White can clear and protect f7, then dropping a pawn at f7 checks (or checkmates!) the Black King. This forces the King into the open, allowing White to either promote the pawn at f7, or immediately go for checkmate. In Shogi, there is no such obvious weak point for Black -- which definitely makes the game more interesting.

Third, most pieces in Shogi do not move symmetrically in all directions. Rather, they are biased for forward movement. Except for the king, rook, and bishop, backward movement is either restricted or impossible. This further balances the drop-check strategy, because the middle of the board -- or even your opponent's side of the board! -- is not so dangerous for your King. If your opponent begins to drop-check against you, you can move your King forward as you escape. The pieces already dropped by your opponent have difficulty moving backwards to attack. To counter this, drop-checkers must drop-check from two sides -- cutting off the King's escape. Further, the attacking player must usually drop-check from a distance, and so defensive drops (where a piece is dropped between an attacking piece and the King) are more useful. Defensive drops are useful in Bughouse, too, but a player on offense will more frequently drop pieces adjacent to the king -- making a defensive drop impossible.

Finally, Shogi provides each player with four unusual pieces -- the Generals -- which are amazingly strong defensive pieces. Each player starts with two Gold and two Silver Generals. A Gold may only move one square at a time in one of six directions -- forward, forward diagonally, to the side, or straight backwards. A Silver may move forward, forward diagonally, or diagonally backwards, but not side-to-side or straight backwards. Such pieces may not seem very versatile, but they do an excellent job of protecting your King! Indeed, just one general can protect three squares around your King, and with three generals, you can ensconce your King in a halo of protection. (Checkmates in Shogi involve identifying the General's weak points -- the squares they cannot attack -- and launching your offenses from those squares. You can also move the weak points by forcing a General to move, say, with a lucrative capture.

Promotion in Shogi is very different. The Golds and the King do not promote, but every other piece does. Most pieces promote into a Gold, but not all. You can promote a piece any time it moves into, inside, or out of your opponent's third of the board. For the bishop and rook, each gains King-like movement upon promotion. My favorite move in Shogi is moving a promoted bishop orthogonally. It feels like cheating!

In conclusion, Shogi is awesome.