I plan to post a new Hex puzzle to this thread about once a week. Here is the first, taken from a game on Playsite. Black to move and win:

A larger image is here. I will post a link to the solution next week. If you wish to discuss variations, You can click here, or message me, or email me. I would be glad to discuss specific moves, either in plain text or with a Jhex file.

Please don't post your answer in this thread; give others a chance. Other types of comments are welcome.

Sorry the email link was broken. Here it is again: twixt@cstone.net

Nice (difficult) puzzle. I haven't been able to find the answer yet.

Pandelis

i've just seen this puzzles on the forum i think its b9 :)

ups sorry shame on me…. im really sorry for this i havent read the message to the end my foult it wil not happen again i promise. once again sorry

It would be nice to see the answer to the puzzle to see if what we worked out is correct.

btw I think b9 is not the answer. It can be followed be c8-b8-c6 for examble.

hmm i think that threaten the connection from f8 on the right side would be very helpful -there is the wall of black stones from e7 to h4 that can be helpful after all

hmm i think that threaten the connection from f8 on the right side would be very helpful -there is the wall of black stones from e7 to h4 that can be helpful after all

there might be 2 winning moves…

E9, I5, and I8 all seem to win for black, there could be other responses as well, but B9 is not one of them, if there are any

i know b9 was wrong

So… What are the solutions and can we expect a new puzzle? :-)

There are indeed many options to win like i5 and i8 ..but isn't it the idea to find the quickest win? … my vote for that would be f8

F8 loses to E10. See my previous post for the correct solutions. There is no need to go through each possibility tree and find the “fastest” win. In fact, it appears that all of the correct solutions are very simliar, and might all take the same number of moves any way. It's irrelevant either way though, the only important thing is that the win is forced rather than relies on a mistake from your opponent.

Oh, and I'm not sure if David is planning on posting anymore puzzles or not. Maybe he's waiting for some good 13x13 situations as 10x10 is too easy after 5 or so moves into the game.

(Spoilers)

What's wrong with B9?

Black moves B9, forcing White to block at C8.

Then, black moves B8, forcing White to block at B7.

Then black moves to C7, and White can't block both connections. So 1. b9 c8 2. b8 b7 3. c7 wins for Black.

Did I miss something?

Nevermind, I see it now.

Black's B8 doesn't force B7, it forces C6(for white to win anyway)…

after b8 white goes to c6 like said agoui before:)

This is a nice puzzle, indeed. It is when one is forewarned that there is something going on then she/he may pay attention to finding this something. In real games, if one can see it right away, she/he is a very strong Hex player. Have a wonderful weekend.

How wins black with E9? I'm a beginner in hex. After E8 I would lose with black.

bE9, wE8, bF8, wF7, bG7, wG6, bI5, wH6, bJ6, wI6, bJ5, and there’s nothing white can do to connect to the right side

H7 also seems to win. E.g. H7, H8, E9, E8, F8, F7, G7.

Also, B9 is *NOT* a losing move! It just doesn't help.

After white defends against B9 (e.g. B9, C8, B8, C6),

black can still win by playing H7 or any of the other

winning moves already mentioned.

i see H7 losing to G7…

Hmmn. That's what I get for posting an answer after

looking at it for maybe 20 seconds. I didn't consider

G7 in response to H7. It does seem to work but it's

not trivial. E.g.

1.H7 G7 2.I8 H9 (not 2…H8 3.F8 E10 4.F9 etc.)

3.F8 E10 4.F9 (G9 doesn't work either) F10

5.I9 H8! (the only winning move) 6.J6 I7 7.J7 I5