I’m giving away an open-ended Go thought book that I wrote over a few weekends. It contains 8 professional game positions. You can spend a few minutes or a few hours thinking about each one, finding as many good variations as you think exist, and choosing the best one. Then I give my view. The goal is to develop originality of analysis and planning.
Enjoy it!
Thank you, Mark! This sounds brilliant! (Also, when is the study group coming back?)
Not soon. I’m expecting a new baby this month. But you can contribute a new position if you want to!
On Board 1, the most important thing for White seems to be to
escape with the weak top left group, connecting to the top side / centre with the tesuji G18.
Black cannot cut due to the variation wG18 / F18 F19 / H18+ F16+! / G19x G16+ / E19x E16.
Otherwise, we could try wE19 / D19 G18, which is better endgame. However, Black can consider wE19 / G18!? D19+ / A16 C18x with a doubled-edged ko. That gets really messy…
Wait, no!
wE19 / G18?? A16! and Black is dead, since he simultaneously requires both D19 for the right eye and A19 for the left. So White can freely play the wE19 D19 G18 connection.
On Board 2, Black looks weak at first glance but he really isn’t that easy to attack.
There is something off about
the direct cut E15 E14 F14. The empty tiger’s mouth shape just doesn’t look right, from a shape and liberty perspective.
G15 fails to wG15 / F16 G16 / E17 E16 / G17+ F16 / H17! (threat. E18) E18 / G14 etc.
I think that in a real game I would think for a long time and then just play
the G16 kosumi, and think to myself “I suppose I will play a steady and thick move, and see what comes of it – there’s no need to hurry around the board.”
But in review, I would have to ask myself whether I’d played too slowly, and I’d try out alternate lines.
Actually, I would probably first exchange
the D12 peep for the C12 connection, reducing Black’s eyespace. Then I’d play G16.
I don 't think I’d be taking long to think about Board 4.
It’s much more likely that it’s due to my weakness than my strength, but I only see one realistic move:
the L4 press onto Black’s three weak bottom-side stones, eg. continuing wL4 / M3 M4 / N2 N4 / O2.
What are the alternatives?
M4 is easily cut apart by variations like wM4? / L4 L5 / M5 N5+? / K5+ M6x / J5 H5 / J4+ and wM4? / L4 L5 / M5 K5 / N5.
And if we instead play the iron pillar N4, Black can just push up to L4 and split our stones.
My aim would be to play through
wL4 / M3 M4 / N2 N4 / O2 and then just connect at H5, fixing the shape and asking Black about the status of his five stones on the left side.
Is anyone still interested in studying this book?
I came to the same conclusion as @bugcat for board 1, but
My first thought was simply R17. On the other hand, Black didn’t respond to G3 so G2 should be a good move too. I didn’t see a good reason to play on the top left right now.
I’d start with H5. This threatens E5 so Black needs to defend the cutting stones. Then L4 can follow.
No idea for board 3 for the moment. Let’s try
The group C3 is in danger, and Black has peeped at K6. Connecting at J6 seems too passive. E6 is more active: if Black responds with D6 then White is connected (since Black H5 would be followed by White G6), so White may continue escaping towards J9 and try to make a second eye, aiming at the cuts K13 or M12 although I don’t really know how.
My basic positional judgement was the same as jlt’s, that the endangerment of the C3 group, which appears to be locally dead, is the dominant aspect of the position.
I can’t see the value of playing E6 or D6 now, since those moves don’t look to make an eye. I’d rather save them as threats in case the status of this group eventually becomes ko.
If White must connect then how so? I think there are four moves that retain connection: H5, J6, and the fancier L7 and L5 which rely on being able to net the cutting stone if the cut is made without reinforcement. H5 is worse than J6, not impacting the peep stone; L5 is worse than L7, since L7 moves into the centre.
Secondary check: can we do anything else in the position? I spent some time thinking about the cut at K13. The conclusion I came to is that if White takes the K13 cut Black will force three times in sente along the twelfth rank (K13 K12+ J13 J12 H13 H12 G13), sacrificing the five upper stones, and he will then return to take the cut at or around J6. This is a losing strategy for White.
So my conclusion is that we should start with L7. After a black response like L6 or K5, we can then connect at J6 and begin looking for our second eye.