Computers are good and extremely deep analysis of chess like positions, but there is one thing that pevents that--having many possible moves to choose from on each turn, that greatly increases the bredth of the search tree making the depth much harder to acheive. Typically a mid game in chess has about 40 possible moves available.
Consider the best Western chess programs play about the level of the World Champion--as shown in several well publicized matches:
My understanding is that computer xiangqi programs
are grandmaster standard,
Xiang qi has fewer moves available through most of the game than chess--even though it has the same number of pieces. Generals (Kings) and advisors are limited to the castle. Guards are limited to their half of the board.
I'd say there are roughly moves available per turn in midgame as in chess maybe slightly fewer than chess. Say about 40 or.
computer shogi programs are amateur dan standard (though this may
have improved since I last heard)
The drop rule means that the players have far more moves available per turn. Pretty much any piece that is captured can be dropped into almost any vacant square on the board! (Pawns are the major exception. No two unporomted pawns may be dropped in the same row.) In midgame it if the players have several available pieces to drop, they could easily have several hundred potential moves to chppse from. This lows down the computer's analysis to crawl.
and computer Go programs are unremarkable amateur club player standard.
Go not only hase a large number of available moves per turn--basically the player can places a piece in empty space of which there are 200-300 in mid game.), but also the game is far less amenable to computer analysis than chess and its related games. It can be very hard to determine which groups are safe or not. Shifting of a single piece (sometimes at the opposite end of the board) may make the difference!
Go is also a game where if you are losing in one part of the board, the best thing to do is to strengthen yourself elsewhere.
Computers tend to be best at tactical play in Chess--but Go's emphasis is largely on the strategic play. It is not really a surprise.