Hello Alan. This was a training game from 2015. I turned a player on to this training game recently. He has become a friend (player) on TwixTlive. Bob 440.is his name. After going through this game he asked me about 12.r7 sets up what he calls a "naked achilles" ( no supporting pegs). Now,Myself included, are wondering about 13.p8
|13.p8 is my first thought. It's a strong threat across the top with the 0-5 gap to j6. It's vulnerable, but it looks like that vulnerability leads to a cascade attack: 14.o615.o516.n817.q618.o1019.q10 and that leaves me in a good position to come up from the bottom: 20.n14 and now I don't see any good moves for White.
Thanks very much! Although I hadn't quite gotten around to framing it as a question, what you've shown me is that that "naked achilles" isn't as vulnerable as I've been assuming.
On 2019-11-02 at 11:30, Alan Hensel said:
You're very welcome. Although I think of every defensive pattern (such as "naked achilles") in context, not necessarily vulnerable or strong in and of itself. Part of what makes it work is that the s11 peg is .5 below the crucial diagonal (w2 - m22); if it were 1.5 above, the achilles would be vulnerable on the right side. On the left side, there is the j6 - j10 - i12 group with a strong connection to the left, and White needs to stretch so far to block r7's connection to it that he must leave a gap, which enables a double threat that may start with something like m12 or n10.
In this teaching game I led flounder through the classic windmill-style opening, which, I should note, TwixtBot totally does not go along with. My hunch is there is a lot more to know about opening moves.
|13.p8 14.o8 15.n9 16.q7 17.m7 18.p9 19.p10
what am I missing?
23.s15 24.q17 25.t17 26.s21 or 23.s17 24.q15 25.t15 26.t14
Also, I think we missed something in your original line: |13.p8 14.o8 15.n9 and then 16.p6 instead, and then 17.m7 18.m3, 19.m5 20.l5 or 19.m2 20.l5.
|13.p8 14.o8 15.n9 16.p6 17.m7 18.m3 19.m2 20.l5
In these lines, j6 is a supporting peg although it initially appears that it is too distant to contribute
R7 - j6 is a 1-8 gap. 1-8 = beam (0-4) + "naked achilles" (1-4), or coign (1-3) + bastard (2-5), or tilt (3-3) + bastard (2-5). Bastard 2 different ways! Bastard is strong.
R7 - j10 is a 3-8 gap, which is another coign + bastard.