Who are you ?

I am an IT professional of 30 years plus standing doing everything from programming operating systems through to selling and account management of multimillion pound contracts

I am a life long cricket fan, I played, I umpired and I run one of the larger county cricket leagues in the UK

I got really lucky 8 years ago and got a job at the ECB; part of that ended up being running the recreational cricket platform Play-Cricket.com and introducing several new features not least of which is electronic scoring of cricket matches

I have always had an interest in number puzzles and problems and so the nerdy part of sorting out fixtures for cricket leagues came naturally and I spent a Covid lockdown using newly found spare time to automate a lot of the grunt work; hence this web site offering to share

So its cricket fixture fixtures you do ?

Well yes but also not ONLY. If you got here and you are a different sport in a different country then a lot of the same issues are faced

A lot of the issues go across many sports; it is about scheduling the use of shared resources in the most effective way; and not compromising the integrity of the competition along the way.

What other sports could you do ?

Loads of sports have the same constraints on grounds and need to be played when participants have their free (none work time). So if your are a chess league; a baseball league; a netball league or a soccer, hockey, rugby league and you need fixtures you probably work within the same kinds of constraints we do

What is the difference in recreational vs professional fixtures ?

There is quite a lot of similarity; matches need to be scheduled sharing resources in the best way but professional sports have other considerations

Professional sports might need to avoid back to back travel, arrange schedules to suit media. Whereas recreational sports all fixtures for a particular round might be on the same day, TV schedules might well want several of the professional teams to play on different days and times to maximise coverage

Whilst doing fixtures for professional sports is possible in my tool set it may or may not be the best way

So what are those constraints ?

We are talking recreational sports, mainly amateur in nature which are played by people in their leisure time

From a society perspective there are times when a majority of worker take that time off at the same time, usually evenings and weekend, and these are traditionally the time recreation sport especially team sports are played.

Many of these sports then need scarce resources to enable them to be played, traditional team sports very often need a ground or venue, and teams tend to associate themselves with a venue as their home facility.

People also tend to want a routine, so Wednesday evening in the summer might be netball, or Saturday afternoon cricket, or Sunday morning in the winter football

Sports people are competitive and want to measure their performance over a set of matches , a season, against other teams of similar strength

So in organised sports we end up with people playing their sport in leagues at set times in the week at clubs which play at a set venue in contests with other clubs, so we get the concept of home and away matches. The clubs want to make maximum usage of their home facility to increase participation and for economic reasons so may well have 2 teams sharing any given ground

So the problem is to maximise the number of games which each club can play making best use of the facilities

There is another factor, integrity of the competition, which means it would be viewed as unfair for one team to play its last match after all the other matches in that league have been completed or get so far ahead of behind in terms of number of matches the team knew what outcome each possible result would have. Playing at home is often seen as an advantage and it can be seen as unfair for a team to get that home field advantage several times in a row and definitely over the course of a season most sports leagues would expect each team to play as many home matches as away.

Add that all together and that is what a good schedule of fixtures makes possible

So what is the answer ?

There are lots of different answers. there is also not a 1 size fits all answer.

Consider the case where every ground needs to be used on every fixture day to maximise capacity. If that is the only of most important constraint then the solution would be different to a situation were only a few facilities were shared but the some of the facilities where only available on some of the playing dates.

then is it more important everyone plays at the same times and on the same dates, and if everyone plays each other twice is it more important they play teams in the same order in the return fixtures

There are then constraints introduced by the nature of the competition. What if there is a 10 strong premier division of the elite teams, and then several 8 or 12 team divisions organised in a local structure with teams in the premier structure sharing facilities with teams lower down or a set of divisions has a mid season break and the other carry on playing

How do you approach the problem ?

At the heart of the solution are fixture patterns, once you have the patterns that is part of the issue solved as it sorts out the ground sharing issues.

The next bit is applying those patterns to a multi divisional setup; even divisions of different sizes; that can be part science and part art but once done the patterns can then be applied to many situations

The last bit is can you fit all the teams into the patterns without clashes; this is where the tools which does this for me comes in ; hence the claim easy fixtures

Can you tell us a bit more about fixture patterns and how they work ?

They setup teams in divisions in pairs, so if there are 10 teams there are 5 pairs etc. The first team in the pair is always at home when the second team is away

The also have other attributes like no more than 2 consecutive home matches, or all play all twice in a symmetrical fashion

Because the same patterns are use across multiple divisions a team in the first slot of a pair in one division will always have opposite fixtures to a team in another division in the second slot in the pair. So teams can share grounds across any number of divisions

How do you start to deal with multiple divisions ?

The patterns generally work together is all play all once; but when all play all twice then the midpoint of the season for the division with more teams is later than that for the division with less teams and the matching across divisions of different sizes breaks down....but

Over the year, part science and part art I have worked out ways around this; something has to give and for instance sometime the order in the second half does not match the first half and things are not entirely symmetrical (but they are unusually close)

I can show that this is the 'best can do' situation but that takes a longer explanation !