Form books, form experts, form summaries - form is everywhere in racing. Whether you're standing in the bar at Beverley races or just watching the action on TV, there is always someone blathering on about form. But what is form and why is it so important? And if IE readers want to really delve into the subject, what are the best sources of form to track down and use?

Horse racing form is all about solid facts. The best place to find these are in the official Form Book (published by Raceform, see raceform.co.uk) which, in two versions, provides details of every race run on the flat and over the jumps each season. Whole tomes are written about form and its interpretation each year. But as a starting point all you have to remember is that, in essence, a horse's form is simply a record of all its achievements whenever it has turned up at a track and run in a race.

Once you think about it, it's easy to see why form is so important. A quick crunch of the numbers reveals why it can be profitable to listen to the views of a decent form expert, even if they are regarded as racing's equivalent of an anorak-toting train-spotter.

Formula for success

The statistics say about a third of contests run are won by the favourite. Throw in wins by the second favourite and that proportion soars even higher. And who are responsible for a horse's position at the head of a betting market? The odds compilers, who work for the major bookies pricing up the markets for all the UK horse races. And how are those markets created? By using form, of course.

A punter who has a decent grasp of form is well placed to take a view on a particular market and exploit opportunities where price and potential outcome appear to be out of kilter. As successful pro punters will tell you, scooping up value bets is the way to staying profitable in racing.

Not that easy

The thing about form is that it'd be a far more straightforward concept understand if, say, every flat race run over the same distance on consistently good going by horses of exactly the same age, carrying identical amounts of weight in their saddles! Given that scenario, if horse A thrashed horse B by ten lengths on a Monday, the chances are a similar result would occur if A and B were to meet again a week later in a similar contest.

Obviously, that kind of example is more akin to a scientif c experiment rather than a horse race. In reality each race features loads of different variables. The key to understanding the 'F' word is to be able to interpret and weigh up those crucial factors, which most affected the outcome of a race in order to build up a wider form picture. Then the skill lies in applying what you have already learnt in predicting how future contests will unfold.

We've listed typical factors in our How To box (click the How To button). If you can't be arsed to get too bogged down in compiling your own form analysis, never fear - we've included suggested sources where you can find out more about a particular variable which can affect the outcome of a race.

Once you've looked at plenty of races, you'll draw your own conclusions about what factors affect form the most. Some experts, for example, attach great significance to race timings and build up tons of information based around this variable taking into account weight carried, distance raced over etc.

Perhaps you will end up siding with Phil Bull, a fearless punter in the post-War period who was adamant that the most important fact a punter needed to know before placing a bet on a horse was a very simple one, namely 'Will it act on the ground?'

Given that between 1943 and 1952 Bull's accumulated winnings equated to about £5 million in today's money, it's probably a question worth asking the next time you have a punt!

Form can be divided into two types, indirect (or collateral) and direct. Collateral form is useful because it allows punters to make a comparison of the relative merits of two horses which are meeting in a race for the first time. This can be carried out when each of these horses has run against a third horse, which can be used as a comparative yardstick for form purposes.

Collateral damage or direct lines?

However, the most reliable form lines are direct ones. For example, if Horse A beats Horse B in a contest, the chances are he will do so again in a rematch when the conditions are similar.

A great example of this came in 2004's turf flat racing season. Saeed bin Suroor-trained Rule of Law (ROL) raced four times, all at level weights, against Let the Lion Roar (LTLR) from John Dunlop's powerful yard, coming out on top every time. The first clash was in the 2004 Derby when second-placed ROL (behind North Light) beat third-placed LTLR by a head. The pair next met in the Irish Derby when fourth-placed ROL beat fifth placed Lion by two and a half lengths.

Next came the Great Voltigeur at York's Ebor meeting. ROL beat LTLR into second by two and a half lengths. Fast forward to the St.Leger last September, where anyone who backed LTLR to turn the tables on ROL surely needed their head examining. And so it proved. ROL won the last Classic of the season with Lion trailing-in in eighth - about a dozen lengths adrift!

This is known as 'franking the form' and sounds blindingly obvious. So it's surprising the number of times punters, often swayed by media hype and other external factors in the run-up to big races, often desert a tried-and- tested performer in order to give a rival 'one last go'. Remember, only turn your back on form in the book when there are outstandingly good reasons to do so.