I got quite excited about a poem recently. Part of it was along the lines of, “Crane Flies change the spin of a cricket ball at Lords, and get burnt in their thousands”.

Woah I think, is this the cricket equivalent of ‘The Butterfly Effect’.

An insect weighing less than a feather changing the dynamics of an important sporting event. And get incinerated in their 1000’s as a result. I must find out more…

The Butterfly Effect.

I first heard of the Butterfly Effect from Dave Snowden. Dave was talking about how linear ‘cause and effect’ relationships don’t work in complex systems.

He said something along the lines of; “if butterflies flapping their wings in the Amazon really do cause tornadoes in Texas, I know a few Texans who would burn the place down to get rid of them”.

Edward Lorenz the American Meteorologist launched the concept of the Butterfly Effect in a talk titled: “Predictability: Does the Flap of a Butterfly’s Wings in Brazil Set Off a Tornado in Texas?”.

The point was that small actions (the flap of butterfly wings) can theoretically lead to large outcomes (Tornados in Texas).

And they could also lead to the total opposite, absolute calm.

And many other things in between.

The point of this and Lorenz’s earlier work is that it is not possible to carry out accurate long term predictions of the weather.

It’s a complex system.

The other point to note is that the concept of the Butterfly Effect has been massively misinterpreted in lots of popular culture and management theory teaching.

Yes small actions can have big impacts, but it isn’t as predictable or as common or as certain as some people suggest.

Straightforward linear, cause and effect relationships don’t play out in complex systems especially biological ones.

Unless you are a Crane Fly…

First a bit of Crane Fly biology.

Many people will probably know Crane Flies as ‘Daddy Long Legs’. They enter the house on late summer evenings and cause mayhem.

At the sight of a single Crane Fly, normally calm people will run around flapping their arms as if a dog size Vampire Bat has appeared.

They aren’t dangerous, just look a bit scary with long legs, big wings and a small body.

How on earth can these things change the spin of a cricket ball?…

They don’t.

Leatherjackets at Lords.

More biology. This is where the ‘grub’ stage of the Crane Fly comes into play.

Leatherjackets, are the grub stage of the lifecycle that live in the soil, for most of their life, munching on roots.

In some places they exist in large numbers and are considered a pest.

Back in May 1935 London had a major infestation of Leatherjackets in Parks, Tennis Courts, Golf Courses and Lords Cricket Ground.

So many, that according to Cricket’s Strangest Matches radical action was required.

“There were bald patches on the wicket, and spinners found it to their liking”.

In non-Cricket language, leatherjackets had damaged the playing surface and changed the nature of the game.

Terminate, with extreme prejudice

The response was extreme.

There were some nature based suggestions like, ‘get more Swallows’. Apparently Swallows can stuff themselves with so many Crane Flies that they struggle to get off the ground.

I like that.

There’s a Robin in the garden that follows me around when I’m digging. Occasionally it walks home to it’s nest rather than fly because it’s eaten too many earthworms.

Eventually at Lords the Groundskeepers collected up Leatherjackets, put them in bags and ‘burned the lot’.

Some days between, 1300 and 1400 ‘brace’ of Leatherjackets were incinerated.

Quite the insect barbecue and termination with extreme prejudice.

I’m not sure if there were any unintended consequences, but nobody seems to have mentioned a Lords Leatherjacket problem since 1935.

The Butterfly Effect and Lords Leatherjackets.

Unfortunately, there doesn’t seem to be an obvious link between the Butterfly Effect and the Lords Leatherjackets (a cool Indie Band name though).

The Lords Leatherjackets were part of a system where the link between ‘cause’ (leatherjackets burrows) and ‘effect’ (damaged wicket) was clear and obvious. So was a solution.

In the complex field of predicting the weather there are far too many variables and thousands of possibilities for what might happen.

Many unknown, some unknowable and a few catastrophic.

You can’t hang all that on a single Butterfly.

So, What’s the PONT?

1. Small actions can have big impacts. The Butterfly Effect is a useful metaphor.

2. But recognise that in complex systems it is not possible to predict what that impact will be.

3. Please don’t worry about Crane Flies and burn them (or anything else). The Swallows enjoy them.