The online performance of this year’s top ten Grand National bookies will put a dampener on Post-Aintree celebrations, website performance data published today has claimed.

As Investors in Britain’s bookmakers breathed a sigh of relief as Numbersixvalverde prevented the joint favourites from romping home, saving them from huge payouts, consistent errors plaguing online sports betting web sites put a shadow of doubt on their financial performance in the online race, according to web testing firm SciVisum.

The research showed that seven out of 10 of the bookmaker’s web sites tested exceeded the industry average of 0.01 per cent for errors over the three week period leading up to the Grand National, with one web site effectively being out of the online race to capture punters for six hours in a week. During this period people were unable to login to place bets.

Out of the five leading High Street and five Pure Play brands tested, the BetDirect, William Hill and Skybet websites were the best performers showing the least web site errors overall.

“With a total of more than £250m staked on the Grand National industry-wide, bookies can’t afford to have such a crippling performance online,” said Deri Jones, CEO, SciVisum.

“The race showed the increasing status of the Grand National in the country's affections, which presents a massive financial opportunity to the online sports betting sites. There is so much riding today on website performance, as bookies compete to win over online betters."

He added that it is shocking that some bookies appear to have entered “a three legged horse” in the online race.

Alarmingly, the study pointed to “a definitive slow down” of website performance on the day of the Grand National itself, with one web site slowing down by more than 230 per cent. As gamblers rushed online to place last minute bets and get the results of the race on the day, the research showed that overall the web sites peaked in user logins during 12.00pm and 8.00pm.