IF David Beattie was on Mastermind he would not chose football as his specialist subject, which is an interesting admission for a man in his position.

There are plenty of football club chairmen who act as if they know it all. The man in charge of Partick Thistle is their polar opposite. "It would be fair to say I'm the worst football fan at the club," he says. "I probably know the least about the football side of it. I've always been a fan but never a supporter: in other words, I always looked at the papers and the results, but I was never at the games."

Actually, "never" is not quite true. His late father, John, was a great Thistle man and when David was a wee lad he would lift him over the turnstiles into Firhill. That planted a seed that lay dormant until it was stirred by his own son, Shaun, and somehow affection for Thistle and his business connections resulted in him falling into the chairmanship. During a boozy night on a golfing holiday with friends on the Firhill board, Beattie, now 58, talked so passionately about the club they decided that he should take control of it. "I don't profess to know a lot about football. I don't even try to, but we surround ourselves with people who do."

By that he means manager Alan Archibald and general manager Ian Maxwell, but any suggestion that Beattie and his directors have stumbled upon good fortune fails to acknowledge how business is now done at Partick Thistle. Since he became chairman the club has implemented a strict spending policy – crucially, understood and adhered to by all at Firhill – which has slashed its debt and returned it to Scottish football's top division for the first time since 2004.

Beattie may claim to know little about the game but he is crystal clear on this much: Thistle's debt was almost £3m and now it stands at £600,000. Next season, in the new Scottish Professional Football League, turnover will double to £2.6m. Archibald inherited a young squad constructed by his predecessor, Jackie McNamara, and there is every reason for them to be optimistic about being in the top flight for more than a single season. Hearts' 15-point deduction all but guarantees that club will be in the automatic relegation place or the play-off, which greatly improves Thistle's odds.

In 1998, it took a spirited Save The Jags campaign to prevent the club going bankrupt. Now the Thistle formula mixes economic discipline with shrewd player recruitment and good management. There's nothing revolutionary in it. "We add up everything it costs to run the club and finance the staff, and whatever we have left is for the playing budget," says Beattie. "It's not rocket science. Our plan for four years has just been to create a sustainable football club. That's not very exciting and it's not very sexy, but it's the most important thing you can do. There's a long-term plan here."

Football can make even experienced businessmen feel like the new boy in town on day one at a bigger school. Beattie represented Thistle at what turned out to be the penultimate meeting of all 12 SPL clubs earlier this month. He felt it was his place to keep relatively quiet. "It's about finding your feet. I went to the meeting. I said very little to be honest. It was interesting to see all the characters. I was just assessing the different dynamics of that boardroom – a lot of strong people in there, a lot of strong characters."

In his own business life, Beattie made his money in a major bakery business and remains the chairman of another one. Routine football politics and personalities will never be daunting for a man who was diagnosed with throat cancer shortly after becoming Thistle chairman and is now, thankfully, in remission.

He owns only five per cent of the club's shares and is also one of a benign consortium which owns Firhill's old, wooden main stand and the grass banking behind the south goal. There is planning permission for 79 flats, a commercial centre and some retail outlets there, plus a small stand, although no deal has been struck with any developer.

Beattie and his directors have taken some heat from supporters recently over another Firhill issue, namely them being moved from their favoured North Stand next season because away fans can no longer be trusted – or safely accommodated – in the wooden stand. The use of smoke bombs by Celtic and Rangers supporters at the Glasgow Cup final, held at Firhill, means away supporters can no longer be put in the wooden stand in case they set it on fire.

The problem is those fans who carry flares or smoke bombs. "It's something we don't need in the game, quite honestly. It's not adding to the atmosphere. It's becoming a problem [in Scottish football]. Somebody could get hurt with one of these flares. Our hands are tied. There would be 10,000 at the Celtic game and we have a duty of care to 10,000, not a few people [the unhappy group of Thistle fans] whose views I do understand. We need to look at the big picture."

Falling out with some of their own supporters pains Beattie because he prides himself on being transparent and honest with them. "Our commitment to the fans is this: if you come in and you pay your £20 at the turnstile that goes into the playing budget, because we've covered our costs. The more people come, the more money 'Archie' has. It's a very, very simple equation.

"If the other clubs in the division have more fans, they have more resources. But there is a big dormant support for Partick Thistle and I think a lot of them will start coming to games next season. We've budgeted for another thousand fans per game and I think that we will achieve that."

He starts off again about sustainability, living within their means, all of that stuff. But he stops himself: "I'm becoming boring now." Not at all. After nine years out of the top flight, one of the oldest clubs in the country feels like a refreshing new face.