If you’re a regular follower of tipsters or betting systems then you may well have come across occasions where your winnings haven’t turned out to be as much as you thought they’d be.

Maybe you put £10 on an 8/1 shot and were expecting to receive winnings of £80, but instead received only £60. At first you may think there’s been a mistake or you didn’t put the right wager on. But in fact it could mean you have encountered what is called a “rule 4 deduction.”

This is when a horse (or horses) drops out of a race before the start, thus increasing the chances of the remaining horses to win. To compensate for this, the bookies make a deduction from the winning horse’s odds depending on when people put their bets on.

So if a horse is second favourite and the favourite drops out, it means that the second favourite will become the favourite.

The amount of the deduction is calculated by working out the chances of the horse of winning based on its odds. So if a horse was 4/1, that means it had a 20% chance of winning and if it drops out, the other horses will have a 20% greater chance of winning.

So under a rule 4 deduction, you would see your winnings reduced by 20%.

One of the major difficulties in rule 4 deductions though is that they are generally not recorded in the racing results. So if you look at sites like the Racing Post, Sporting Life, the BBC or RacingUK, you won’t see any details of rule 4 deductions. This can be a little frustrating if you are trying to work out how much various horses would have had their odds affected by horses being withdrawn, particularly if there are multiple withdrawals.

We see this quite a bit with tipsters, who don’t take into account rule 4 deductions in their results, thus making their results look much better than they actually are.

Horse racing betting at top UK bookmaker William Hill also applies Rule 4 according to Tattersalls Committee. Of course, you will also find the latest odds for today’s races, ante-post bets as well the full horse racing results and much more.

There are websites that record all rule 4 deductions in their entirety and allows you to see what the deduction is depending on when you put your bet on such as the top bookies. At least this is something we should be thankful for.

It is good to see this kind of transparency and it is a website we often use ourselves. We make sure that all the tipsters we are trialling have rule 4 deductions included so that results are accurate. It may not sound like a big thing, but if a horse that was a 20/1 shot then has the favourite at 5/4 drop out of the race, it will greatly affect the winnings on that horse was 20/1.

So do keep an eye on that in results and it is worth asking tipsters you encounter whether they include rule 4 deductions in their results.

The final Group One of Royal Ascot 2017 is the Diamond Jubilee Stakes, taking place on Saturday, June 24. The six-furlong race gets underway at 16.20 and comprises a competitive-looking field that is sure to have the majority of punters scratching their heads as they aim to unearth this year’s winner.

The 2016 running of the Diamond Jubilee Stakes was won by Twilight Son at a price of 7/2. Ryan Moore was on board the Henry Candy-trained four-year-old to cap off a magnificent festival for the jockey. He finished ahead of Gold Fun and Signs of Blessing, although the first five home were only separated by just a length.

Only nine ran in the contest 12 months ago but this year’s renewal looks set to be significantly more competitive with a larger field full of in-form candidates.

The Diamond Jubilee Stakes is the fourth race on Saturday’s competitive-looking card immediately following the Group Two Hardwicke Stakes and Henry Candy is aiming for back-to-back successes in this contest.

Limato didn’t compete in last year’s renewal, with the ground not adequate enough for him. The predicted temperate climate in Berkshire leading up to the five-day festival should be more suited to his needs on this occasion.

Candy’s runner is expected to go off as the favourite, but with less than a week until the final Group One race, he can still be backed at around 5/1 for success.

Limato failed to land a blow in the Al Quoz Sprint in Meydan at the end of March, where he finished tenth in a 12-runner race under the stewardship of Harry Bentley. The rain-softened ground was blamed for the inadequate display. The Irish-bred five-year-old has run twice at Ascot, finishing first and second, with both races competed on good ground. Limato looks likely to get his favoured going in this year’s renewal.

His trainer is confident that Limato can get back to form at the festival stating that he is “happy with him” and confident of further improvement this season. That being said, the July Cup winner will have his hands full against a quality field.

The Tin Man is also likely to be prominent in the betting and the runner-up in the Haydock Sprint Cup is likely to run a big race for trainer James Fanshawe.

The five-year-old has been in action fairly recently when coming fifth at York in the Group Two Duke of York Clipper Logistic Stakes on May 17. He finished just five lengths behind the William Haggas-trained Tasleet.

He is another runner who is familiar with this track, having won the QIPCO British Champions Sprint Stakes in October. The race was both on good ground and over six furlongs, with very similar conditions as expected on the final day of Royal Ascot. 

The Tin Man is one of a number of distance specialists in the field, winning 50% of its races over the six furlongs. Connections are confident of a big run.

Magical Memory is another one who thrives over this length and could lay down a significant challenge to the top two in the market. Charlie Hills has a very good record with sprinters and will have his charge ready for this contest. Frankie Dettori is booked to ride the Irish-bred star but suffered a fall at Yarmouth recently, plunging his participation at Royal Ascot into doubt. Luckily, the Italian jockey avoided any serious injury and is likely to be fit enough to partner Magical Memory in Diamond Jubilee Stakes.

His last racecourse action came at York in the same Group Two race as the Tin Man finishing second – just two and a half lengths behind the winner. The Hills runner is back for another crack at the Diamond Jubilee Stakes after finishing a close fourth in last year’s contest.

This year’s renewal looks to be one of the most difficult races to predict at the festival and there aren’t always enough hours in the day to assess every runner’s chances across each of the five days. Daily tips can be found at comparison sites including Oddschecker from pundits such as Andy Holding and Sam Turner to help steer punters in the right direction ahead of the top-class action.

Looking for a third top-level success is Quiet Reflection, who could go off at a double-figure price for trainer Karl Burke. She rattled home in the Commonwealth Cup at last year’s festival and is likely to be competitive in this event. The trainer believes she will be fitter for her run at Haydock at the end of May. The four-year-old finished a disappointing tenth in the Temple Stakes but that run should have blown away the cobwebs. She enjoys running over the six furlongs and was successful in the Sprint Cup.

There are a number of runners at much bigger prices who could potentially reward connections and punters alike. Long on Value travels over from the USA and is aiming to make the extensive commute worthwhile. Trainer William Mott believes his charge can land a surprise over the six furlongs on the final day.

The six-year-old came second in the aforementioned Al Quoz Sprint, narrowly losing out to The Right Man but relished the damp conditions underfoot. Long On Value has been preparing for the race on the gallops at Newmarket with his handlers praising their stable star, suggesting he looked “totally relaxed” in the UK.

The Meydan runner-up is likely to renew hostilities with his conqueror The Right Man, who is priced up at around 14/1 for success at Royal Ascot with a week to go until the event. The French-bred horse has his work cut out on better ground, with many of the field aiming for revenge this time around.

Goldolphin send Jungle Cat for the Diamond Jubilee Stakes and trainer Charlie Appleby is confident of his chances over the six furlongs. The five-year-old is also entered in the Darley July Cup Stakes at the end of next month but also has the option to race at Curragh the following day.

Appleby has won just twice with Jungle Cat since taking over the reins from Mark Johnston, although it ran a creditable fourth at last year’s festival. William Buick rode the Meydan winner to a narrow defeat behind Clive Cox’s Profitable, who gamely held on to claim the King’s Stand Stakes over five furlongs.

Finally, Signs of Blessing returns to the scene of last year’s third place finish and is looking to go two better this time around. The six-year-old has also been entered into the King’s Stand Stakes on the opening day of the festival and the choice of race will be decided nearer the time.

The French-bred horse prepared for the festival with a convincing victory at Deauville on May 13th, beating the aforementioned Profitable by two lengths. Having won eight of its 21 starts and placing at the Berkshire track twice in 2016, connections are confident of another huge run, whichever contest it may come in.

There are a number of odd-on favourites competing earlier in the week with many bookmakers fearing the worst at this year’s festival but Saturday’s card looks particularly tasty. The Diamond Jubilee Stakes is set to be extremely competitive and a bigger price winner would not prove at all surprising. Limato could thrive back on his favoured ground but there are a number of distance specialists who will be waiting to pounce if Henry Candy’s runner doesn’t live up to expectations. Raiders arriving from overseas will be aiming to repay their travel fees with success and it is set to be a mouthwatering contest to bring the curtain down on Royal Ascot 2017.