The Game In Action

The Game in Action

Here's a short game that illustrates several facets of Crumble.

1) 2,1VW ...

Black's first move, shown above, is not the only choice, but seems to be a good solid opening. It already aims at creating an impervious central piece. The White piece above the two rectangles will figure strongly in this game. If left alone, Black's plan is to first remove the swappability of that piece, and then occupy it.

1) ... 3,5HS

White's response neglects the center. The two squares to the left and right of the rectangles White has created are unlikely to become strong White pieces. White, however, is trying to create long chains of pieces that might soon be connected in serious threats to win.

2) 3,2HNNW ...

Black is also trying to create long chains - while simultaneously working on the imperviousness of that central White piece. Notice that Black doesn't care that the move extends White's chain. Black knows that White is not in a position to make any serious threats yet.

2) ... 1,3HSSS+

With this move, White says "check." But White has not been making any attempt to create impervious or redundant connections, and so this threat is not very serious. Black can block it in any number of ways. White's immediate threat is 3) ... 5,3HN, with a won position.

Incidentally, the best way for a beginner to start to understand the dynamics of Crumble moves is to get into check. When we were playtesting Crumble at Google in 2008-2010, often a newcomer would have no idea why they might play one move instead of another. The difficulties posed by a "check" would give them concrete problems to solve. After that, they'd start to have a better idea of the significance of any given move, and the variety of goals it might accomplish.

3) 2,3VENE+ ...

With the above move, Black also says "check". But Black has no illusions that this is part of a winning attack. In fact, Black's real threat is now to imperviously occupy that central white square. If Black is allowed to do that, White will have very few chances.

But in fact, Black's move is too early. Until the central white square is occupied imperviously, it could still end up white. A better move would have been to forget about making check threats, and play 3) 1,2V2-1E-E, iterating a renewable to make sure White couldn't quickly reoccupy the central square; and thus paving the way for the move in the text.

This hypothetical position is more complicated than the position in the actual game, because both sides have renewables that can occupy the central target square. Black should come out on top, but the impervious central piece would not be as strong as it was in the game.


3) ... 5,3HNWN+

White again says "check", blocking Black's threat to win and making one of White's own. But it was essential to prevent Black's next move. White's moves have not been great so far, but this one is a real blunder. White should at least try to confuse the issue with 3) ... 1HNN (which also threatens a large capture), or take away Black's prize entirely, with 3) ... 2,2VW.

4) 1,2VE ...

Black's loose play has not been punished, and the central black square is now completely impervious, with three strong black rectangles shooting off of it. White's position is probably already lost here, in spite of the fact that material is even and neither side is touching more than two edges of the board.

It's worth pointing out how quickly the position got interesting. This is only Black's 4th move, and we are definitely still in the opening phase of the game; but the opponents are strongly engaged with each other, and there are lots of strategic and tactical motifs.

4) ... 3,4V2-2W-W

White iterates a renewable, cutting Black off from the top of the board. White's renewable gives the appearance of strength, preventing Black from re-occupying the strategically significant square White has just occupied. In reality that square is not so important. But it does give the illusion of a strong white chain in the center.

White's new strategy (now that Black has closed off any central pathway) is to arc that chain over Black's central blockade, and connect the upper left corner with the lower right, winning the game.

However, since this can't be achieved (try making white moves in the upper left, and you'll quickly see that no breakthrough can be forced), it would be better to focus on preventing Black from extending the strong chain across the board, hoping someday to undermine Black's central connections.

5) 3VW ...

Black's simple move, connecting the central piece with the lower edge, can't be immediately countered. Usually Black would have to wait and lay more groundwork before playing a move like this. But in the current game, if White tries to re-occupy the square Black has just swapped into, White would only be connecting Black to the lower edge by a different route.

Between Black's impervious piece in the center, and the redundancy of Black's lower left quadrant, it's clear that White's position is nearly smashed. In addition to everything else, Black now threatens a relatively large capture, with 6) 0,1HSE.

5) ... 3,1VE

White ignores Black's threat, and pursues the dream of the win - only one piece stands between White and a won position. But even so, White's move isn't even a "check".

6) 5,4HSSS+ ...

"Check". Black is after bigger game than just capturing a few pieces. For the moment, Black knows the new connection to the right edge is fragile. But in order to break it, White will be forced to leave open the possibility of a much stronger black connection on that side. Meanwhile, Black's capture threat is still in play.

6) ... 5,1HSWN

White breaks' Black's right-edge connection, but this plays into Black's hands. The white square above the pieces White has just split can now be occupied with imperviousness. A similar result would have occurred if White had tried to finesse, with 6) ... 6,1HSWWN, 7) 5HNW, and White can't stop Black from strongly connecting to the right edge of the board, as in the game.

In a battle of this kind, it's not enough to go back and forth, gaining and losing an advantage until the local resources of the position run out. Always look for moves that lead quickly to the outcome you desire - in this instance, a strong connection to the right edge.

Back to the game:

7) 6,3HNWS ...

Now Black's connection to the right edge is much stronger. White can only delay the inevitable.

7) ... 6,1HN

White's move breaks' Black's connection, but not for long. This is also the second time White has swapped a half-piece into another half-piece. After this move, instead of an 18:18 material balance, Black has a 19:17 advantage. If Black now were to play the big capture in the lower left quadrant, Black would have a 20½:15½ (or 5 piece) advantage.

White would have done slightly better doing the same move as the text, but with a long split, 7) ... 3,1H3-3N-N, containing the threat of 8) ... 3,1J1,2W, breaking Black's connection to the bottom.

Black would have something to say about this, of course. But the above hypothetical positions illustrate the defensive resources and multi-pronged tactics that can often be found in even the most dire Crumble positions.

Returning to the game:

8) 6,7HNW+ ...

"Check." Black's move is a feint. On the surface it threatens to win, but in fact Black is preparing a move that will imperviously solidify the connection to the right edge of the board.

8) ... 6,9VW

White blocks Black's threat to win.

9) 6,6J1,2SSS++

"Crumblemate". With the first join of the game, Black reestablishes the connection to the right edge of the board, in a way that can no longer be broken. The rest of Black's position is equally unassailable, and Black has two separate winning threats in the upper left quadrant.

White resigns.

In a friendly game, instead of "crumblemate", a player would more often say, "I think this is crumblemate". Then both players would try to find a way out. Some fascinating combinations can be discovered this way, especially if you allow takebacks, and carefully record all moves.