There was a keen and widely shared sense of loss among racing fans on social media on Sunday evening as news emerged that Nicky Henderson’s Shishkin, one of the most talented and engagingly quirky chasers of recent years, had died after fracturing a hind leg having become cast in his box at Henderson’s yard in Lambourn.

It was a hugely unfortunate conclusion to a storied career in which the hero’s flaws and foibles only added to his appeal.

Through his first two-and-a-half seasons on the track, barring a fall at the second flight on his hurdles debut in December 2019, Shishkin was unbeatable, as he ran up a 10-race winning streak that includes Grade One wins over both hurdles and fences at the Cheltenham Festival and an epic one-length defeat of Energumene in the Clarence House Chase at Ascot in January 2022 that will feature in “top 10 greatest races” lists for as long as there are punters alive to remember it.

Related: ‘Superstar’ Shishkin dies after suffering leg fracture at Henderson stable

Both horses arrived at Ascot with unbeaten records over fences, and while Shishkin set off as the narrow favourite, it was Energumene who was odds-on in running as he jumped the last around two lengths in front. The 15 seconds from the final fence to the line, as Shishkin clawed his way back and then passed Energumene a few strides from the post, were as compelling and memorable as anything the sport has seen in recent decades.

It was a career-defining moment for Shishkin but, perhaps, a turning point too, as if the effort of chasing down such a talented opponent had taken him to a place that he was not inclined to revisit. He was again odds-on for his next start, in the Queen Mother Champion Chase at Cheltenham, but he was not travelling or jumping with any enthusiasm at any stage and was pulled up before jumping the eighth fence.

Having won 11 of his first 12 starts, Shishkin completed his racing career with three wins from nine, but his sudden vulnerability seemed only to increase his popularity with racing fans. He was still capable of high-class form, including Grade One wins at Ascot and Aintree in the spring of 2023, but he was the beaten favourite in the Ryanair Chase at Cheltenham in between those victories, albeit having rallied to within three lengths of the winner at the line after a crunching mistake three out that would have stopped many horses in their tracks.

Shishkin’s quirkiness bubbled to the surface once again in November 2023 when he planted himself at the start and refused to race before the 1965 Chase at Ascot. He jumped off without a second thought in the King George VI Chase at Kempton a month later, however, and seemed poised to register the biggest win of his career when he stumbled and unseated Nico de Boinville – his constant partner throughout his 21-race career – after jumping the second-last.

A comfortable win at Newbury in February seemed to tee up Shishkin perfectly for last month’s Cheltenham Gold Cup, but he was among a host of runners from Henderson’s yard that were scratched from their intended races at the Festival as the trainer struggled with an apparent bug in the yard at the worst possible moment in the racing year.

Henderson’s string is slowly emerging from its malaise and he saddled the final Grade One winner of the 2023-24 season in Britain when Jonbon beat El Fabiolo in the Celebration Chase at Sandown on Saturday. Jonbon is now the highest-rated chaser in training, but the loss of Shishkin, who was rated just 1lb behind Jonbon, still leaves a huge hole at one of the country’s most consistently successful jumping yards.

Shishkin was due to travel to Ireland on Monday ahead of a clash with Galopin Des Champs, the dual Gold Cup winner at Cheltenham, in the Punchestown Gold Cup on Wednesday. However, on Sunday he was found to have rolled into a position in which his legs were too close to the wall for him to be able to stand up, and had suffered a fracture to a hind leg as a result.

That leaves a respectable fourth in a Grade One at Aintree earlier this month as the last entry on Shishkin’s racing record, while his Timeform rating still carries the squiggle – denoting a horse with a dubious temperament – that he earned for his refusal to race earlier in the season. It is intended to be a warning sign for punters, the mark of an unreliable performer. For a fascinating, multi-faceted character like Shishkin, however, it had quickly started to feel more like a badge of honour.