British Champions Day: Your guide to the richest race day in Britain

Flat racing's 2017 season climaxes with the seventh staging of Qipco Champions Day, Britain's richest race day, at which many of Europe's top horses will compete for more than £4m in prize money.

Brazil-born jockey Silvestre de Sousa will be crowned champion for a second time, and trainer Aidan O'Brien - who goes into the day one short of the world record for Group One race wins in a year - will claim his sixth title.

Here, BBC horse racing correspondent Cornelius Lysaght runs the rule over some of the feature races.

• Trainer Aidan O'Brien chasing record

• Champion jockey De Sousa relishes second title

• Racecards for Champions Day

Race: Long Distance Cup (13:25 BST)

Status: Group Two. First prize: £263,000. Distance: Two miles.

Overview: Big Orange and Order Of St George are set for a rematch after Big Orange came out on top by just a short head in a rousing Gold Cup at Royal Ascot in June.

While Order of St George has since won two races and been a fine fourth in the Prix de l'Arc de Triomphe, Big Orange suffered an honourable defeat - by Stradivarius, who went on to be third in the St Leger - at Glorious Goodwood, before missing a race on Arc weekend following heavy rain and a "restless night" in the stables.

Desert Skyline was third in that Goodwood race but won the Doncaster Cup with authority, and has the invaluable assistance of champion jockey De Sousa, who, considering he's now won his second title, seems surprisingly short on rides during the day.

Look out for: The ever-popular, front-running Big Orange is pure box office; wearing his heart on his sleeve, he's a joy to follow and watch.

They say: "I saw him work the other day, and he's in great form. It's half a mile less than the Gold Cup, but he's won two Group Two races over a mile and a half, so that's not a worry" - Big Orange part-owner Tim Gredley.

Conclusion: Too much rain isn't great for Big Orange, but a repeat of his gutsy display in the Gold Cup clearly puts him bang in there, and arch-rival Order Of St George must have had a reasonably hard race in the Arc 20 days previously.

Three-year-olds Desert Skyline and Stradivarius both come to Ascot off the back of good runs at Doncaster's St Leger fixture, and either could be capable of inflicting an upset on the 'big two'.

James Doyle rode Big Orange to victory over Ryan Moore on Order of St George in the Gold Cup at Ascot in June

Race: Champions Sprint Stakes (14:00)

Status: Group One. First prize: £340,000. Distance: Six furlongs.

Overview: Though Caravaggio - one of 11 Group One-race runners during the card for record-seeking Aidan O'Brien - defeated Harry Angel at Royal Ascot, that horse got revenge in the July Cup before following up in style in the Haydock Sprint Cup.

The 2016 Haydock winner, the filly Quiet Reflection, representing the in-form stable of Karl Burke, bounced back after an absence in September.

The Tin Man defends the title he won 12 months ago at a track at which he excels.

Look out for: Harry Angel, ridden as usual by jockey Adam Kirby, is improving all the time, and was simply breathtaking at Haydock.

They say: "The gap between Haydock and Champions Day is perfect timing. He's very well and in a good frame of mind. We've got no concerns from a going point of view" - Harry Angel's trainer Clive Cox

Conclusion: What a terrific race with so much sprinting talent on display, and it's good to see so much of it is British-trained. Harry Angel really does have superstar quality, and he's expected to confirm form with Caravaggio, but could be pressed hard by Quiet Reflection, who carries a little less weight because of the fillies' allowance.

Race: Queen Elizabeth II Stakes (15:15)

Status: Group One. First prize: £623,000. Distance: One mile.

Overview: Godolphin's Ribchester, flagbearer of trainer Richard Fahey's powerful Malton-based team, is the outstanding miler having carried all before him for Group One prizes at Newbury,

Royal Ascot and at Chantilly in France. Defeat at Glorious Goodwood came on such a foul day that any horse can be forgiven a narrow defeat by a wily old hand like Here Comes When.

Churchill, for Aidan O'Brien, did the Newmarket/Irish 2000 Guineas double but has since been beaten three times. French challenger Al Wukair was third in the Newmarket Guineas, while Beat The Bank has only been beaten once in six starts.

Look out for: Beat The Bank is owned, like Leicester City, by big-spending Vichai Srivaddhanaprabha, whose jockeys wear silks in the Premier League club's blue and white. This horse is on a relentless upward curve, and seemed to leave trainer Andrew Balding almost speechless such was the manner of his most recent success at Newmarket.

They say: "The way Beat The Bank won the Joel Stakes [at Newmarket] suggests he might have a chance at the highest level. Having won a Group Two by four lengths - he won it emphatically - he thoroughly deserves a step up in class" - Andrew Balding.

Conclusion: Ribchester is the obvious choice, but Beat The Bank is a fascinating contender from a stable that has enjoyed an excellent season. The horse needs to progress again to win, but it would be no major surprise if he pulled it off and ensured his owner ended the week on a high after a tumultuous time at King Power Stadium.

O'Brien has trained 24 Group or Grade One winners in 2017

Race: Champion Stakes (15:50)

Status: Group One. First prize: £737,000. Distance: Mile and a quarter.

Overview: Having been in the frame in the Epsom and Irish Derbies, Cracksman, trained by John Gosden and ridden by Frankie Dettori, won at York and Chantilly.

Though he missed the Arc - won by his stablemate Enable - Gosden has said he believes the colt would have been in the first three.

This distance will suit Arc fifth Brametot. Barney Roy has enjoyed a splendid year, with two wins - including in the St James Palace Stakes at Royal Ascot - and a string of close-run things.

Sir Michael Stoute is without Ulysses, but saddles Poet's Word, who ran a storming second in the Irish Champion Stakes.

They say: "Cracksman is coming back in distance, and we are taking on older horses which is something different. He's bigger and stronger than he's ever been, but I see next year being a very important year as a four-year-old" - John Gosden

Conclusion: Cracksman has obviously done exceptionally well during 2017, but what he's achieved is not as great as two other three-year-olds in Barney Roy and Brametot. Barney Roy is going to have new, hold-up tactics employed. Brametot is a dual Classic winner at home in France, and would have played a bigger part in the Arc if it was staged over his (shorter) distance. Reports are very positive about the four-year-old Poet's Word, whose second place in Ireland was an excellent effort.