Grand National Betting History – Biggest Wins at 100/1

No race in the world has produced more bewildering results than the Grand National. The four miles, two furlongs, and thirty fences of Aintree’s National Course have a talent for destroying logic, shredding form books, and handing victory to horses that most of the betting public had written off before the starter dropped his flag. Five winners in the race’s history went off at 100/1 — the absolute maximum most bookmakers will offer — and several others were barely more fancied.

This is not trivia. It is the most important structural fact about Grand National betting. In a race where roughly £250 million changes hands annually, and where 82% of cash bets are staked at £5 or less according to Entain data, the longshot tradition is the engine that drives the entire market. People bet on the Grand National precisely because against all odds, anything can happen. The historical record proves they are right.

The Five 100/1 Winners in Grand National History

The first came in 1928, and the story of Tipperary Tim remains one of the most absurd in sporting history. Of the 42 starters, only two finished. Fence after fence claimed fallers, and by the final stretch Tipperary Tim — a moderate horse at best — simply had to stay upright and keep moving. His amateur jockey, Bill Dutton, was reportedly told by a friend before the race that he would only win if all the others fell. That is more or less what happened. The horse had no business being in front, but he was the only one left standing.

Gregalach followed in 1929, though his 100/1 price was arguably less justified. He was a decent animal in mixed company, but bookmakers had assessed the enormous 66-strong field and concluded he had no realistic chance. A front-running ride through the chaos of Aintree proved them wrong. In an era before televised racing, his victory was reported in stunned newspaper headlines the following morning.

Caughoo, in 1947, benefited from fog so thick that spectators at Aintree could barely see the runners. The 100/1 winner reportedly took an unorthodox route, and conspiracy theories about the race swirled for years afterwards. Whether or not the fog played a decisive role, the result was official, and bookmakers paid out on one of the most controversial Nationals ever run.

Foinavon, in 1967, produced perhaps the most famous scene in Grand National history. At the 23rd fence — a small obstacle that should not have caused any trouble — a loose horse ran across the field and caused a mass pile-up. Nearly every runner was brought down, refused, or was pulled up. Foinavon, so far behind the leaders that he had time to pick his way through the carnage, jumped the fence cleanly and galloped clear. His jockey John Buckingham rode the final circuit virtually alone. The fence has been called the Foinavon fence ever since.

The most recent 100/1 winner was Mon Mome in 2009, and his victory carried a modern twist. Unlike the earlier centurions, Mon Mome won a properly competitive Grand National on good ground, beating a full field of quality chasers. Trained by Venetia Williams and ridden by Liam Treadwell, he jumped with precision and stayed on powerfully up the run-in. The 100/1 price looked generous at the time, but bookmakers had underestimated his ability to handle the unique Aintree test. It remains the most recent reminder that the market can get the Grand National spectacularly wrong.

Other Major Upsets: Noble Yeats, Auroras Encore, Rule The World

Beyond the 100/1 club, the Grand National has delivered a steady stream of results that confounded the betting public. Noble Yeats, the 2022 winner at 50/1, was a seven-year-old with limited experience over fences and no obvious Grand National profile. Yet he travelled smoothly throughout and outstayed far more fancied rivals in the closing stages. The market had been fixated on Any Second Now and Escaria Ten — both finished behind him.

Auroras Encore, the 2013 victor at 66/1, came from a small Yorkshire yard and was virtually ignored in pre-race coverage. Trained by Sue Smith, he was considered a quirky horse who had shown flashes of ability without ever putting together a convincing winning sequence. At Aintree, everything clicked. He jumped fluently and was never headed once he hit the front. His victory is often cited as evidence that the Grand National rewards soundness and jumping ability over raw speed — qualities that do not always show up in the form book.

Rule The World, the 2016 winner at 33/1, added another dimension to the upset narrative. He had been off the track for almost a year with a pelvic injury, and only his trainer Mouse Morris’s faith in the horse kept him on the entry list. His return to racing was the Grand National itself, a decision that looked reckless until he delivered one of the most composed performances in recent Aintree history. He was the first novice to win the race since 1958.

What these upsets share is not randomness but a specific kind of underestimation. In each case, the horse had a genuine asset — jumping accuracy, stamina, course suitability — that the betting market undervalued. The market focuses heavily on recent form, trainer statistics, and public profile. The Grand National consistently exposes the blind spots in that approach.

Average Winner Odds Over the Decades

The headline number that gets repeated in every Grand National preview is this: the average winning odds sit somewhere around 20/1. That figure is broadly accurate across the modern era, though it hides considerable variation decade to decade.

Through the 2000s, the average crept higher as the field size and fence severity produced wilder results. Mon Mome at 100/1 and Comply or Die at 7/1 in consecutive years illustrate the absurd range. The 2010s brought some degree of rationalisation — Tiger Roll winning back-to-back at 10/1 and 4/1 was historically unusual, suggesting the market was getting sharper at pricing the best-credentialed runners. But then 2022 delivered Noble Yeats at 50/1, snapping any illusion of predictability.

The most instructive pattern is what happens in the 10/1 to 25/1 band. This is where the plurality of winners fall. Horses like Many Clouds (25/1 in 2015), One For Arthur (14/1 in 2017), and I Am Maximus (7/1 in 2024) all sat in this territory. The market assigns them a chance — somewhere between 4% and 9% implied probability — and often gets the assessment roughly right, even if it struggles with precisely which horse in that band will win on the day.

The data across recent decades, as compiled by resources like horseracing.guide, confirms that short-priced favourites in the 3/1 to 5/1 range win the Grand National far less often than they would in an ordinary handicap chase. Favourites succeed roughly 15% of the time in the National, compared with around 30% across all jump racing. The extra distance, the unique fences, and the size of the field all conspire against the obvious choice.

What Longshot History Means for Your Betting

The lesson from Grand National betting history is not that you should blindly back the longest-priced horse in the field. It is that the market systematically overprices short-priced contenders and underprices the middle band of 12/1 to 33/1 runners who have the attributes Aintree demands: stamina, jumping reliability, and the temperament to handle a chaotic field. The 100/1 winners make for brilliant stories, but the real value over time has been found among the unfashionable horses in that middle tier — the ones good enough to complete the course and strong enough to keep galloping when others tire.

If this history teaches anything, it is to respect the race’s capacity for surprise and to size your bets accordingly. The Grand National is not a race for putting your entire budget on a single selection. It is a race where spreading your stake across two or three live contenders in the 14/1 to 33/1 range gives you the best structural chance of landing something meaningful — against all odds.