Sounds like a simple premise however a few key questions need clarifying and some rules are required.

What counts as London?

There are many ways to try and classify the area.

• City of London
• London Post Codes
• Greater London Authorities
• TFL overage area
• CAMRA London Brances

There is a rationale for using all of the above however, they all have their pitfalls. The City of London is too small and not what people think of when you state London, so that would be misleading. Post Codes sounds great but the London Post Codes are the compass based ones i.e. N, W, E, and again much like City of London it doesn't cover all of what people consider to be London. Greater London is what most people would assume when you say "London" however there are instances where it becomes hard to identify if a pub falls into the area, and a more physical boundary would be better. TFL coverage area is ever expanding outside of London and is therefore unreliable. CAMRA branches are even harder to visualise/workout and are also susceptible to change.

I required something that is static and unlikely to change whilst also representing and covering all the areas people think of as London. This led me to settle on that oh so magical loop around London called the M25. I'll clearly know if a pub is inside or outside the area as there's a huge stonking motorway seperating. The area is unlikely to change due to boundary changes and it's encompaases all the other above measurement styles (nearly).

What counts as a pub

Again this sounds almost ridiculous. Of course we all know what is and isn't a pub....but it turns out there is a thin line and so I required some assistance. I firstly turned to whatpub.com from CAMRA as it lists all the pubs in the UK on there but I soon learned that they also seemed to include theatres, hotel bars, football club bars and even restaurants. That wasn't to do. Working off data from their website I set about applying a litmus test to the venues to help determine if they were a pub. These criteria are:

• The ability to order a drink without having to order food
• Should not as standard, charge an entry fee
• Should be a permament fixture (Not temporary pop-ups / festival bars)
• Have at least two draught beers available on keg/cask
• If a hotel bar, it should have it's own separate public facing entrance and not require walking through the hotel

These aren't definitive codified rules on what constitutes a pub. For example I've no doubt you could go into quite a few restaurants that have 2+ keg beers on and will serve you a drink without the requirement for food. The criteria doesn't remove the common sense of "it's a restaurant"

What counts as a visit

This one was the most clear cut.

• I must purchase at least half a pint of beer/cider or a bottle of beer greater than 275ml. Accumlated totals such as flights of beer count
• I must check-in the beer and it's location to untappd. This will act as my data validation based on geolocation, time, and what I drank. (excluding technical difficulties where I might have to log at next location or following day)