Sokobanesque Puzzle (Solution included)

Jun 24, 2009, 8:14 AM |

I gave this puzzle that name because it reminded me of a fun Japanese puzzle-game I played on the computer when I was younger.

According to NM Dan Heisman, this problem falls in the category of "indicative" in that the way you tackle this problem clearly tells you where you currently are in your chess progress.

Another think I love about this problem is how it illustrates how a "plan" can extend nearly 20+ moves deep and yet be so simple and easy to grasp. Try telling a computer that! :)

Altogether a fantastically fun puzzle that will have you smiling when you work it out. A solution will be provided if required.

BONUS ROUND: Plug this into your favorite chess engine and if it is weak enough, you may get to watch the computer squirm in bewilderment. Chances are it will find it ... but it sure is fun to watch a computer struggle to see something that a human can either see or grasp so quickly.

White to Move and Win!



Rather than a series of precise moves, here is the plan.

Step 1. First things first! The Black a pawn is passed, so we better take care of that. Shame on you if you didn't realize that! Also notice that Black's King cannot vacate [a7,b8] so all his moves will be back-and-forth like the pendulum of a clock. Of course, if our King were to nudge forward to a6, we'd be in a STALEMATE. Remember this fact!

Step 2. Now the only remaining black pawn that White's King can capture is sitting on f3. Did you spot that? Good ... now go get it!

Step 3. So now what? White's King cannot make progress and pushing the f pawn to the newly created square on f3 does nothing for us.  It would be really cool if we could politely ask Black to push his other f-pawn into that space. Then the win would be immediate :) Of course, Black will do no such thing. Just go back and forth with his King, back and forth .... Any ideas?

Remember Step 1. where we talked about the stalemate? Now that Black's got a free square, it is no longer stalemate if we walk our king up to a6!

Step 4. Once our king reaches a6, black is forced to play f3!!! The POINT!!!

Step 5. Now run all the way back with the King (Hence the Sokoban reference ... this King must be training to run the marathon!) and gobble up f3.

Step 6. Get the king out of the way and break with the f4 pawn push! The rest of the win is pretty clear. Let me know if I need to illustrate that.

Kudos to Lycan148 for figuring this out. Yes, this was easy, but ... certainly fun! :)