I'll try to kick away.
Why I'm even thinking this way is because if you go back 3 or 4 minutes from the timeline listed above (27:36), the commentator (I can't remember his name, though I've listen to several of his videos), says several times that Fischer is transposing one weakness for another.
So, now that we have come this far, I ask myself, what are the two weaknesses according to Point Count? When the Knight on d4 takes on e6 and Black retakes, I see the change from Hanging Phalanx to Hanging Pawns. Before timeline 27:36, I see a Hanging Phalanx (two pawns side by side), a definite and countable weakness. So what does it transpose into? Well, yes, there's a backward pawn on e6 supporting d5, but the rest of the Hanging Phalanx still stands. But now one side is supported, where a move ago it wasn't.
So what is this new animal? What would H&M-S say it is? As they say in the summary (quoted in my May 18th comments
) "but connection on one side does not guarantee safety of the pawn on the other side", so one pawn can be the advanced pawn of a chain, with the other pawn next to it.
Ok. So those definitions listed above clearly put this in the Hanging Pawn category. The c5-pawn is definitely under attack, as if it moves, the White Queen will take Black's Queen. A new weakness has appeared on e6 (and in some sense the weakness on d5 has been transfered to e6
). Because of the transfer of the weakness, the fact that now the one of two pawns in the Hanging Phalanx (that were both weak before)is not weak any longer (I think this is where the Hanging Phalanx no longer is one, because of the transfer of the weakness), yet the transformation has produced a set of pawns that are isolated from their compadre pawns, we would have to call this new formation a Hanging Pawn structure.
So the Point shifts from a Hanging Phalanx, where both pawns are vulnerable, to Hanging Pawns, where two pawns are vulnerable, but not the same pawns as before.
So that begs the question, shouldn't the weakness on e6 be classified as a Backward Pawn? I would agree a point should be awarded for that if it is under attack
. If it is not under attack, the pawn formation is still weak, but different than a Phalanx, so I'll call that weakness Hanging Pawns.
This is definitely not H&M-S clearest chapter as far as differentiating between the two. The glossary has Hanging Pawns as "a phalanx on the fourth rank, not connected on either side (I believe they mean by that, not connected to the 2nd rank on either side in a full pawn chain); Broadly, any pawn group that is under frontal attack and cannot safely be advanced" (PPC, p.336). The c5-pawn is definitely under attack in this example in the video.
The difficulty we as the reader encounter, is that H&M-S include both Hanging Pawns and Hanging Phalanx in their table on page 8, immediately after one another, so they must
see a difference. The definition uses the term "Broadly" and "any pawn group" (implying that it can be more than two pawns). If we are to keep the entire list on page 8, how else would we define hanging Pawns verses Hanging Phalanx? I would be open to your interpretation, and welcome a different way of looking at it. The way I see it, while all Hanging Phalanx's are (a subset of) Hanging Pawns, not all Hanging Pawns are Hanging Phalanx's!
Thus I am disagreeing somewhat with the Commentator at the timeline above (27:36), in that he talks about them no longer being hanging pawns. He also says that d5 is now weaker (I don't see that, I see d5 as stronger because of the supporting pawn, at least temporarily).
I think it is semantics somewhat, but H&M-S are trying to put everything into its own box. You could call what is there (the 3 pawns) a "Pawn Island" (this term is used a lot elsewhere), or we could label it a "Hanging Pawn Island", but I don't think that would be any better than Hanging Pawns and Hanging Phalanx.
Forgive my ramblings here, but to me, when there is a transfer of weakness, there is a different structure. What we call both structures is up for debate, I'll admit. From my reading and thinking, I think H&M-S leans this way too. But I am willing to be proven wrong. There is only one Point at stake here, whether Hanging Pawn or Hanging Phalanx. Two Points would be too much for the position (unless the Backward Pawn is under attack, then a Point for it; basically a Point for each weakness under attack).
Hope that helps. That's how I wrap my head around this issue.