John Boyle took his first punt on Sunderland nearly a quarter of a century ago - when he stuck a fiver on a team rated at 9 to 2 outsiders to beat Leeds United in the 1973 FA Cup final - and came away smiling.

Yesterday, the Northerner was back for another piece of the action as he and the Sunderland chairman, Niall Quinn, publicly confirmed the Irish bookmaking chain Boylesports would be the club's major sponsor for "at least" the next four years.

Quinn was, as might be expected, exuberant about the deal, which, he said, marks a major advance in commercial terms.

Club and company would "make hay together", he said with a broad smile before indicating the performance-related contract could be worth some £10 million in the event Sunderland won promotion to the premiership and then continued to make solid progress over the next few seasons.

A sizeable percentage of the money would come in performance-related bonuses, on which Boyle, to the obvious discomfort of his business partner, was chirpily predicting he would be paying out.

Beside the pair of them, Roy Keane looked on with only the slightest hint of a smile from time to time as great things were foreseen for his promotion-chasing side.

"Top of the league," sighed the veteran bookmaker, whose chain of shops has been extended from one to 111 these past 18 years, during which time a substantial online operation has also been established.

"What a pleasure it is to be here at a Premiership club that, for now, is playing in the Championship. Please God in the next couple of weeks that will change. I look forward to being here next year and welcoming the likes of Manchester United."

At this stage, Quinn was obliged to intervene for the first time: "Eh, we have a little bit to go there, John."

His guest, however, was not easily deterred. The former international had lauded Boyle's ambition for his business as matching that to be found around the Stadium of Light these days but it wasn't until Boyle revealed his target was to oversee the "biggest betting company in the world" that we got a sense of just what was being suggested here.

On the one hand Keane, with his aim-for-the-top philosophy, might have been pleased, but when Boyle was asked how big he could envisage Sunderland becoming over the next few years he seemed at something of a loss for the words required to convey the true scale of it all.

What he did manage, though, were a couple of specifics: "I would say, to be honest with you, Premiership winners and I would see them as Champions League winners."

There was also a more general prediction of great things: "There's no end to success when you have big goals and the right team, then it's easy.

"You're following a success formula that can't fail. I've just come in to a formula that can't fail."

Even before Boyle reached the end of his answer Quinn was tugging nervously at his shirt collar: "I think it might be wise to urge a bit of caution," he interjected, though surely he, more than most, should be aware the bookies rarely get it wrong.