'Go with your gut feeling - you're not a mug if you take the money'

Paul Dean is a born punter. His mind works to percentages, value, profit and loss. He knows cashing out on a bet doesn't make sense mathematically, which is why on more than one occasion he has told his friends to never cash out.

However, it's a bit different when there's more than half a million quid on the line.

That was the situation in which Dean famously found himself the night before the Marsh Novices' Chase at Cheltenham this year. He had watched Shishkin and Bob Olinger add to the wins of Golden Horde and Hello Youmzain at Royal Ascot, and a £5 ante-post accumulator was now rolling on to Envoi Allen in the Marsh. Victory would have earned him £511,225 from that single bet. Defeat would have left him with nothing.