Temperature has been a consistent theme of the proceedings in Court 12 at the Old Bailey this past week. If the court was Arctic in the morning, it would be the Sahara by mid-afternoon, degrees of extreme which caused Mr Justice Forbes, who presides over racing’s “trial of the century” with a sharp eye and a wry wit, to entertain the possibility of turning on the air conditioning units or doffing wigs. He preferred the doffing.

By midweek, though, the temperature in court was pleasant again and the early piccolo of tension had been drowned by the steady beat of the legal drum. For the next three to four months, the rhythm will be much the same, an inching progress towards justice punctuated by the occasional, often unexpected, quickstep.

Kieren Fallon enjoyed two early results: the first was to return to Court 12 on Monday morning as the winner of the Prix de l’Arc de Triomphe on Dylan Thomas, a quite remarkable victory in the circumstances, and the second was successfully to apply for both he and his five codefendants, including two other jockeys - Darren Williams and Fergal Lynch - to be allowed out of the dock to sit with their counsel in the main body of the court. The move not only allowed the six-time champion to be released from behind the glass to sit next to Jane Glass, a barrister on the team of John Kelsey-Fry, Fallon’s QC, but also to be within arm’s length of a copy of the Racing Post, neatly tucked away amidst the complex architecture of folders, binders and documents which is in danger of overwhelming the whole back row.

On Monday and Tuesday, Fallon heard the prosecution case outlined by Jonathan Caplan QC, which included references to multiple mobile phones allegedly used as part of the conspiracy to fix the results of 27 races between December 2002 and August 2004. Fallon heard himself described by the prosecution as “one of the leading jockeys in the world” and, in a skilfully worked reference by Kelsey-Fry to last Sunday’s Arc triumph, as a jockey still at the height of his powers, one who was “driven by a desire to win”. The same could be said of Kelsey-Fry himself. “If I lose,” he said in a recent interview, “it means months of self-flagellating sulk.” Less flatteringly, Fallon heard himself being described as “thick” and “not playing with a full stack” by professional gambler Miles Rodgers, the alleged mastermind of the scam, during recorded telephone conversations.

In the early exchanges between Caplan for the prosecution, Peter Kelson QC for Rodgers, and Kelsey-Fry, there were tantalising glimpses of the evidence that will emerge on both sides in the coming weeks. “You will be concerned with 27 races that were run on various racecourses in this country between December 2002 and the end of August 2004,” said Caplan in his opening remarks to the jury. “The prosecution case is that there was an unlawful agreement or conspiracy between these defendants and other persons that those races should be fixed.” The conspiracy, he added, was not to ensure that a particular horse won, but to ensure that a particular horse lost.

The prosecution alleges that the conspiracy was operated by Rodgers, who used numerous different accounts to lay the horses in question on Betfair, the internet betting exchange. The total amount laid on the 27 races was £2.12m. Fallon was one of the three riders in question, having ridden in 17 of the races. Twelve of his horses lost and five won, Caplan said, resulting in a net loss of about £338,000 for the alleged conspirators.

“The plan was not, and could not be, foolproof because you could not always stop the horse if in the particular circumstances it would look too obvious,” said Caplan. “A horserace is a dynamic event and anything can happen. But the plan worked most of the time.” The contention was later ridiculed by Kelsey-Fry, who noted the “absurd equation” of this “extraordinary case”.

It has been an interesting and enlightening week in Court 12, where the jury have been given a crash course in the art of betting on the exchanges, learnt about “drifting” and “dropping hands”, among other racing colloquialisms, and about how to stop horses if they should ever want to, by, for example, riding into a wall of horses in front of them or inadvertently losing ground at the start.

They have also been educated in the differences between Australian and English racing, where the former requires jockeys to ride out to the line and the latter to obtain the best possible placing. The difference, Kelsey-Fry said, was significant in putting into context the evidence of Ray Murrihy, an Australian whose expertise has been used by the prosecution to analyse the 27 races, and in explaining the case of Ballinger Ridge, the one horse where, says the defence, Fallon made a “howler”, the one horse “that would have won but for what Mr Fallon did, no argument about that”.

Of the 27 races, two were picked out for particular attention: one was Ballinger Ridge at Lingfield on March 2, 2004, a race on which Rodgers had staked £72,312 to win £26,599. The other was Russian Rhythm in the Lockinge Stakes at Newbury in May 2004, a race Fallon had won and which had cost Rodgers £160,256. The jury heard how Ballinger Ridge had built up a huge lead turning into the straight at Lingfield that afternoon. According to the prosecution, Ballinger Ridge “should have won in a canter” but did not do so because Fallon stopped riding and the horse lost momentum. Ballinger Ridge was beaten a shorthead by Rye. “Was this just a terrible mistake or did he [Fallon] want Rye to beat him?” asked Caplan. The prosecution claim the latter. The defence interpretation of the race is that Fallon made a blunder, mostly in failing to see Rye, his nearest rival, when he looked over his shoulder to assess the danger before giving his mount a “breather”. Fallon was subsequently banned for 21 days for being in breach of Rule 156 (ie, the horse did not achieve the best possible placing because of a jockey’s error) by the stewards. The period, the defence noted, included the lucrative Dubai World Cup meeting at the end of the month at which Fallon could potentially have earned a lot more than in losing a minor race at Lingfield.

In contrast, Fallon’s riding of Russian Rhythm in the Lockinge, a Group One race at Newbury, was particularly commended by the trainer, Sir Michael Stoute. Stoute, the defence said, thought his stable jockey at the time had given the filly a tremendous ride. How was it then, asked Kelsey-Fry, that the communication between Fallon and Rodgers, through the intermediary, Shaun Lynch, had gone so wrong? After several texts and phone calls between Fallon and Shaun Lynch and between Rodgers and Lynch, Rodgers began to lay the horse roughly 45 minutes before the off. After the race, which Russian Rhythm won by half a length, Rodgers telephoned Shaun Lynch five times between 3.19pm and 7.47pm, the prosecution claiming it was to find out what had gone wrong.

Russian Rhythm’s victory, the jury was told, had three consequences for the alleged conspirators: one was a trip by Shaun Lynch and Rodgers to Leicester racecourse three days later which resulted in Fallon receiving a lift in Rodgers’s car to East Midlands airport, the second was a trip by Rodgers, Shaun Lynch, codefendant Philip Sherkle and Daniel Kinahan, not one of the defendants, to Newmarket in an attempt to confront Fallon in the early hours of May 27 and the third, the activation on May 27 of two mobile phones which the prosecution argues were to be used by Sherkle and Rodgers to provide a more secure method of communication with Fallon on racedays.

The prosecution’s case is that, unhappy at the loss on Russian Rhythm, the conspirators came to Newmarket to make a more reliable working arrangement for stopping horses in the future. The defence maintain that Fallon did not know who Miles Rodgers was and that if he had known him - and known he was banned from all racecourses by the authorities - it would have been “suicidal” to be seen in his company in the car park of Leicester racecourse. “If he didn’t know Miles Rodgers, he cannot be a co-conspirator, can he?” asked Kelsey-Fry.

The jury was also asked to consider exactly what the little “n” meant in the communications between the alleged conspirators on the morning of fixed races. On August 14, Fallon rode Goodwood Spirit at Goodwood. The horse was 2/1 favourite. That day at 11.43am and 12.04pm, Fallon called Sherkle. At 12.08pm he texted him. At 12.09pm, Sherkle texted Rodgers: “6.55 no 4 n”. Between 6.35 and 6.51pm, Rodgers laid Goodwood Spirit for £116,738 to win £29,822. Goodwood Spirit finished third.

According to the prosecution, the “n” denoted nontrier; according to the defence, it meant negative or “not fancied”, a contrast with another text message which had “p” in the text, for positive, said the defence. The evidence from telephone conversations, much of it inaudible, also suggested, according to the prosecution, regular contact between the conspirators or, with Fallon, through an intermediary. Rodgers is heard to tell Fergal Lynch one afternoon at Ripon: “You cannot afford to make a mistake on this one”, which was taken to be a reference to the third in a sequence of fixed races at Ripon. That morning Rodgers had been taped saying: “Little Fergal’s coming out to play today.”

The prosecution maintains there is a revealing set of texts from Fallon the morning after he had ridden Daring Aim, the Queen’s horse, to victory at Newmarket on July 23. The texts were sent to Sherkle on an unregistered phone recovered by the police from the glove compartment of Fallon’s car. One text read: “They will take my licences off me if they drift like that last night. They are watching me.” Another read simply: “No, I can’t chance it.”

The trial is due to continue beyond Christmas, but racing’s landscape has been changed already by the outlines of the case.

Whatever the outcome, the use of police probes, the tracking of individual betting patterns on the exchanges and the tracing of texts on mobile phones have brought the customs and practices, even the language of racing, into sharp focus.

Rumour, whisper, hearsay, the beguiling mix of opinion, truth, half truth and downright lie that has spun racing’s carousel since the days of Charles II is now subject to more sophisticated scrutiny.

Some people are still playing by the old rules. It is up to the jury of seven men and five women in the dimly lit, occasionally equatorial, depths of Court 12 to establish the guilt or innocence of the six defendants. The wider truth is that racing can never be the same again.

The six on trial

Kieren Fallon, age 42, of Tipperary
A leading Flat jockey and six times champion jockey. Was stable jockey for trainer Sir Michael Stoute

Miles Rodgers, 38, of Silkstone, South Yorkshire
A professional gambler with business interests, he was banned from entering racecourses and having dealings with jockeys for two years in March 2004

Darren Williams, 29, of Leyburn, North Yorkshire
A professional and licensed jockey

Philip Sherkle, 42, of Tamworth, Staffordshire
A barman and former furniture shop employee in Dublin

Fergal Lynch, 29, of Boroughbridge, North Yorkshire
Stable jockey for trainer Kevin Ryan until end of 2003 Flat season

Shaun Lynch, 37, of Belfast
Fergal’s older brother had worked for several bookmakers

The charges
Conspiracy to defraud between December 2002 and September 2004 by interfering with the running of horses to ensure they lost races, defrauding Betfair punters and others putting money on the races. Miles Rodgers is also accused of concealing the proceeds of crime. All six deny being part of a race fixing scam