Archive for the ‘Random’ Category

A diverting ticket offer for the Bolshoi

August 3, 2019


So I got this email inviting me to open the attachment for an exciting ticket offer.  That definitely looked like a scam at first glance–why have an attachment in the first place?  Then I thought you would tend to have a hyperlink or a pdf for a scam and the ballet was somewhat of a minority interest.


And when I opened the document the relevant information was presented:


However, (upon several attempts) the link didn’t work:


So I rang the ROH box office, who were very helpful.  They had heard of the offer but thought it was operative from Saturday.  Then they found it on their system.  They agreed that the link didn’t work but didn’t know the right one offhand.

So in the end I managed to book a ticket..I think…

But what a lot of learning points there are here:

  1. Don’t use a % sign in a link–HTTP will be upset
  2. Put stuff in the email body rather than an attachment if at all possible
  3. Don’t send stuff out outside of office hours–it’s difficult to fix if things go wrong.

Bicycling and the permanent headwind

July 30, 2019


Discussion on Facebook

Interesting that the permanent headwind which blows in your face whatever direction you cycle still operates in the hot weather. Clearly its intelligence does not yet equal its malice and agility.

I find that crosswinds are treacherous because: a) they have a similar drag effect to a headwind and b) they have a vastly greater angular range than just head on. Unfortunately that pretty much encapsulates any wind direction. Get out early if you can, before the thermals kick in.

Have you seen the study that shows the wind is always against you? It’s summarized in New Scientist here and the original paper is here.

Further analysis

OK so now we’ve got onto the purely hypothetical case where you cycle from A to B and then back from B to A and the wind continues to blow from B to A as though nothing had happened.  Even so, the analysis in the references above looks rather complicated.

Let’s ignore rolling resistance and consider a cyclist who wants to cycle on the flat from A to B and back again.  He cycles with a power P which gives a limiting velocity V relative to the air. (In the absence of rolling resistance we ignore interactions with the ground.)

So let’s say as an example B is 10 km from A and V is 20 km/h.  In the absence of any wind it takes 0.5 hours to go from A to B, another 0.5 hours to go from B to A, for a total of 1 hour or 60*60 =3600 seconds.  Then with P measured in joules/second, the energy expended will be 3600*P J.

Now a wind of 10 km/h blows from B to A.  The cyclist’s speed relative to the ground is then 10 km/h on the outward leg and 30 km/h on the return leg.  So the time taken is 60+20  = 80 minutes or 4800 seconds and the energy expended is 4800*P J.

The cyclist has spent more time and expended more energy even with a completely unchanging wind.

This analysis clearly applies to any situation where there is a component of the wind along the cyclist’s direction of motion, even if it doesn’t turn round on you…


Prospects for a new team in Division 4 of the London Chess League

June 16, 2019


The table above shows results from the 2018/19 season of Division 4 of the London Chess League in terms of the final position of the various teams, the percentage of possible game points they achieved, the mean grade of the sides they fielded and the mean grade of the teams they faced.  We can see that the position followed the strength (mean grade) of the teams very closely and there was no significant difference in the strength of the opposition that different teams faced.


We can also consider the relationship between grading and percentage of possible game points achieved, as below.


On this basis, using the equation of the fitted trend line, we can estimate what average grading would be required to achieve various points percentages:


We do not believe that relegation operates from Division 4, but team members would hardly enjoy losing all the time, so we presume that a new team would wish to average at least 40% of game points, requiring an average grade of 113.  Or an average grade of 125 would be required for 50% performance.

We now consider the possible requirements for the specific boards, using the opposition faced by Team 9 (which scored 46%).


So we see that someone playing on Board 4 would meet opposition with a mean grade around 130 and should be of a strength to have a meaningful game with opposition graded between about 100 and about 150.  (Some figures in red italics are affected by the presence of defaults.)

Increase your illiteracy by 34%

June 5, 2019

Detail from an advert on the Tube

I was first of all impressed by the one observation over a whole month in the least representative possible location leading to the claimed 34% increase in income.  But the English language also came in for some rough treatment…


So let’s see what sense we can make of this:

Unlock the potential => let us make money out of you

potential = money

premium => it will cost somebody–everybody!–dear

solutions–perhaps this is ‘lettings’ in English

guest relations => don’t let them stay long enough to acquire any rights

housekeeping => (probably) we can charge you for what we make the ‘guests’ do

Prospects for Lewisham 2 in Division 3 of the London Chess League

June 2, 2019

Happy chess players celebrate promotion

Now that Lewisham Chess Club’s second team has secured promotion to Division 3 of the London Chess League, we can ask what lies in store next season.

The table below shows the ranking of the various teams in this year’s Division 3, together with the average (mean!) grade of the teams they put out and faced, based on information as at 1 June.



The first thing to note is that there is no real difference between the strength of the opposition the various teams faced.  Intuitively enough, the teams with higher mean grades also tended to finish in higher positions, as is shown in the graph below.



We see that you really need to put out teams with an average grading somewhat over 140 to ensure survival.

Next we ask what this means for the various different boards next season.  In Division 4, over 8 boards (as opposed to the ten in Div 3) Lewisham 2 averaged 149, so we take the team ranked 9 in Division 3 with an average grade of 147 as a proxy.



So we would say that someone playing Board 5 would face opponents with an average grade about 160 and should be of such a strength as to have a meaningful game with players graded between about 190 and about 140.


Le Brexit

May 25, 2019


Le Royaume-Uni, patrie du régime parlementaire, désormais sans majorité, désorienté, trébuchant, erratique, canard sans tête. Voici l’œuvre d’un référendum absurde, voulu par un irresponsable, cédant à une presse folle et furieuse, au terme d’une campagne manipulée et mensongère.  Dominique Reynié


Un canard qui nettoie les plumes de son aile gauche avec son bec

More Brexit planning assumptions

December 21, 2018

Man looks at unicorn and remains unconvinced

We have been asked for some further planning assumptions to go with the original set.  These are given below.

Asset prices

The optimistic assumption would be that Brexit does not happen or happens in a way that is not harmful so some of the correction is recovered from what had been priced in on that account.  So say a loss of 10%.  And the middle option would be 20%.

Investment performance

The most optimistic figure that has been canvassed is 3.5%, but this is surely too optimistic in the circumstances.  Say 3%, with a middle figure of 2%.


The question here is really what the difference between inflation and interest rates will be.  The BoE forecasts suggest a real interest rate of around -2%, as at present.  To be more scientific, real interest rates are currently something like -1.75% (0.75% Bank Rate – 2.5% inflation).  The BoE forecasts tend to imply a real interest rate of about -2%, but it would depend on how the rate was adjusted to counter inflation.  Say -2.5%/-2%/-1.5% for pessimistic/middle/optimistic.

As for inflation itself, the optimistic forecast would be that MPC manages to hold inflation to say 2.5% over the period, giving overall inflation of 13%.  So we take 22% as the middle point.

CS Pension

There seems to be no room for variation here.

State Pension

If one assumes 2.5 % inflation then the only room for growth even under the ‘triple lock’ would be if earnings rose faster than inflation.  The latest ONS figures show essentially no real growth in earnings over the period from 2005 (!), so one cannot expect any real increase there either.

Tax rates and allowances

Hard to see any room for giveaways here!

> 60 concessions

Too make things easy for ourselves, we assume that in the optimistic case these survive for the next 5 years, while in the middle case half of them do.


Table of assumptions (unless otherwise stated in real terms and for period 2019-20 to 2024-25)


The pessimistic scenario reflects a coherent view of unmediated Brexit plus asset price correction while the optimistic scenario also reflects a coherent (but unlikely) outcome where Brexit is rendered harmless.  It is hard to give such a definite interpretation to the middle scenario and as such it should be treated with caution.

The treatment of tax and pension changes  as proxied by >60 concessions is very likely insufficient–at the very least, one could consider allowances as being constant in nominal terms, thus reducing in real terms.

The present treatment also implicitly assumes that things remain as they are for the remainder of 2018-19, which is certainly open to challenge.

Planning assumptions for Brexit and after

December 17, 2018


Having grown tired of insomnia, our client has now fled the Civil Service and hopes to avoid starvation by a combination of his investments in bonds and equities, a Civil Service Pension (soon) and a State Pension (not so soon).

He writes:

Meanwhile, I need to make some concrete plans without knowing exactly what is going to happen around Brexit and indeed asset price correction generally. I would like some planning assumptions–the idea is to give a solid basis for planning on the basis that things should not realistically be worse than this.

Our advice is as set out above.  We draw on on the Bank of England forecasts.  These have been criticised on the grounds that:

i)  they take no account of any policy response;

ii)  they are phenomenological, based on observed correlations more than causal modelling.

The point about a policy response is that it can spread the effect out to different times or different people but cannot in general create value from nothing.  So this is really a question of distributional effects–who gets how much of the pain and when–rather than the quantum.

As for correlations, there are times when you need to produce numbers and don’t have time to model the economic universe in detail.  The effect size claimed is similar to that of the credit crunch of 2007/08, which is the nearest–if hardly most similar–comparator.

In summary, our advice would be to look not so much towards the destruction of value (something between significant and staggering) to be expected over the next year but at the effect changed circumstances might have on the revaluation of pensions.

Taking a rather more short-term view focused on the immediate future, our client says:

Applying this set of assumptions to my circumstances, I come to the conclusion that I would lose money that I can afford to lose, which is irritating but no worse than that.

There’s nothing like a satisfied client!  But we can hardly say we have always been in the Brexit loop.  On our first encounter, we took three days to work out what it was, and a further two to decide it could hardly happen.

This analysis has now been extended here.

Recommending a dictionary

December 14, 2018


We were asked by a Russian contact to recommend an English dictionary. I think I would plump for the Concise OED.

Naturally enough, both dictionaries of American English and dictionaries for learners of English are beyond my ken.  A very long time ago (probably before I left school) I got myself a Concise OED.  When I had worn that out I got a copy of the Chambers dictionary (in 1989) on the grounds that it had more words.  The corresponding Wikipedia article has a different opinion, but as they say it depends on how you count entries.

Anyway the single-volume candidates that a native (but non-specialist) English speaker would use seem to be the Concise OED and the offerings from Collins and Chambers.

I had a look at what was available in the shops today.  As for new words, the Concise OED had entries for hashtag and flashmob (as flash mob) while the Collins Reference dictionary didn’t (although it was published later).  It also had something useful to say about the stressing of controversy, while the  Collins Reference didn’t do pronunciation at all.  The large Collins was covered in cellophane while there was no sign of the Chambers.

Back home, I was able to compare some bits of the large Collins and the COED on Amazon.  The Collins annoyed me by including encyclopedia-style entries, which I don’t like, while for  the terms aorist and accusative the Collins tended to flap around giving examples while the COED gave concise, pointed definitions.

While I can’t judge how up-to-date the Chambers is on the basis of my 1989 copy, the definitions of aorist and accusative there are a lot better than the ones in Collins if not quite as good as the Oxford ones.

In general terms, I think that the Oxford dictionaries:

i)   have the most systematic infrastructure for capturing new words and usage;

ii)  have the best definitions and etymologies. (In fact I think that in many cases they have the natural definition since they were there first and other dictionaries have to work round it for reasons of copyright or at least embarrassment);

iii)  are taken as the default in libraries and schools.

So in general you would take the suitable size Oxford dictionary as your default and look to something else only if you had particular needs.  The Concise OED also happens to be cheaper than the other candidates.

Turning now to the Internet, if you’ve got a word that refers to something reasonably definite and you’re dealing with widely-used languages (like English and Russian), your best bet is often to turn to Wikipedia where you can see a picture/chemical formula/mathematical definition/Linnean binominal and compare what the corresponding articles say in the two languages.

Nowadays, if I find that I don’t know an English word it tends to be something I can either look up on Wikipedia or find in the Urban Dictionary.  And there are also resources like OneLook that will search the free online versions of numerous dictionaries for you.


Perm-36 at Pushkin House

October 4, 2018

This film looks very interesting, especially if you have visited the site as it used to be.  Aleksey Kamenskikh says:

It’s a brilliant film! Its author is my friend Sergei Kachkin.  The film itself is not about “politics at present”, it’s theme is “past perfect” of the museum: in 2013-14 Perm-36 was invaded by a pro-governmental group, its conception was radically modified. 

Sergei himself adds:  well, everything is politics and yes, Aleksey is right, my film is not about politics, let’s call it this way – about a human inviroment in nowadays Russia.

I will certainly be going along to this.  Event details are here.

Update:  there will also be a screening at QMUL the following day.  It seems as though you can also stream it on Amazon: