[r-t] Lead head codes redux

Don Morrison dfm at ringing.org
Tue Jun 20 17:30:11 UTC 2017

For the methods collections it has published in recent decades the CCCBR
has adopted succinct coding scheme to describe the lead end and lead head
rows and changes of methods that have Plain Bob or Grandsire lead ends,
using a letter optionally followed by a digit (
http://methods.org.uk/online/notes.htm). While in principle this scheme is
merely a convention adopted in specific, published collections, in practice
it is now a de facto standard.

It contains a curious, and I think unfortunate, asymmetry.

While the Council does appear still to look askance* at them, it's been
over a decade since it was forced, kicking and screaming, to to accept
"short course" methods, such as royal ones with a lead head of 1795038264.

For the single hunt at even stages/twin hunt at odd stages lead end codes
there are suitable gaps, denoted with '*', left for the short course
methods. It's pretty clear that a 2nds place method with a 1795038264 lead
head is a 'c' method, or a 16ths place method with a 1EA9C7D5B3T20486 lead
head is a 'j2' method.

But for the single hunt at odd stages/twin hunt at even stages ones they've
only left gaps for methods whose course length is not half the number of
working bells. For example, while there is a '*' left for p1 at Fourteen,
1297E5A3B4T608, there's no slot for 127593E4A6B8T0, which means such a ends
place methods needs to be described as something silly like p½ (or maybe
p0.5) and a 14ths place 12E9A7B5T30486 would be r1½ or r1.5.

Any idea why this unfortunate asymmetry was built into this scheme? It
seems perfectly plausible to construct methods with the missing lead ends,
even with palindromic symmetry (entertainingly they'll have two pivot
bells!). Is it just prejudice against these methods?

* Don't believe it still looks askance at them? Besides the evidence of
this encoding, and the Council's use of '*' in
http://methods.org.uk/online/notes.htm, look at the naming scheme. While a
(3,1) method like Boxford Bob Doubles gets a first class name, a (2, 2)
method like Baldrick Differential Little Bob Doubles is forced to have a
ponderous name, and a classification that sounds as if it's an
infinitesimal horse used for sport. And all this while Baldrick seems a far
more regular and closer-to-normal method than Boxford, as it does have
Plain Bob lead ends.

Don Morrison <dfm at ringing.org>
"In 1500 BCE there were around 600,000 autonomous polities on
the planet. Today, after many mergers and acquisitions, there
are 193 autonomous polities."       -- Robert Wright, _Nonzero_
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