In every branch of the global entertainment industry which is modern-day sport, overwrought hyperbole is an everyday occurrence, merely a part of the promotional routine. Every twisted ankle is a tragedy. Every flukey winning goal is a life-and-death miracle. Given this climate of exaggeration, you might be sceptical when I say that Mark Courtney's successful return to speedway action last season with the Glasgow Tigers was one of the greatest comebacks ever witnessed, anywhere, in any sport. But trust me when I slip into back-page commentator mode for a second to assure you that while yon boy Lazarus might have done great all those years ago in his bid to get a result in extra time, he had nothing on Mark Courtney's sporting resurrection.

For, while Courtney didn't scale the highest heights of his own previous achievements on two wheels, he did have to begin his climb back towards those peaks from a very deep trough.

This time last year, you see, Courtney was in prison, approaching the halfway mark of a six-year sentence imposed in 1998 for his part in a criminal plot to import cannabis valued by customs authorities at #500,000 into Britain. More to the point, his speedway career had long been in a state of terminal arrest.

Approaching the upper age range for most top riders at 39, Courtney hadn't ridden a speedway motorbike for fully six seasons, his final spell as a Middlesbrough Bear having quietly petered out in 1993 in a mixture of disillusion, knockabout farce and mutual recrimination. This anti-climactic ending - to which we'll eventually return - had been in marked contrast to the golden start of Courtney's speedway career.

In 1980, as an overnight teenage sensation, Courtney had won the British junior championship in his first full year as a professional rider. Two years later, he was runner-up in speedway's world under-21 championship. In that same year, his first in regular competition in British speedway's foremost league, Courtney became a full England international.

Established as the top rider with the Leicester Lions, Courtney was viewed as the young Briton most likely to challenge the top riders from speedway's traditionally dominant nations: Denmark, the United States, Australia, Sweden and Poland.

In addition, he was widely lauded as a smooth stylist, sliding his brakeless 500cc bike round speedway's small oval tracks with seemingly effortless grace and certainty. Such was Mark Courtney's potential back then that, in motorcycling parlance, he had the world at his throttle-hand.

This time last year, however, Courtney's sole contact with speedway was fleeting and distant, taking the form of pay-phone calls from open prison to his family in nearby Middlesbrough, checking on the progress of his elder son, Scott, aged 17, who had just been signed by Glasgow.

''I was very pleased, but very surprised that Scott had become involved with speedway,'' Courtney tells me over a mid-afternoon drink in a pub near his present home. Like the archetypal speedway rider, he's small and wiry, self-reliant, toughened. There's a rough and ready spark to him; a freewheeling air of being in perpetual motion.

This sense of movement is enhanced when Courtney lays out not one but two mobile phones on the table in front of him. They're an essential tool for the speedway rider, almost as indispensable as his two skeletal-looking bikes and the diesel van that carries them.

When speedway's league season is in full swing, operating at three different levels of ability at just over 30 tracks from Poole to Berwick between March and October, riders are nomadic, one-man businesses. In addition to being contracted to one particular British club, riders can earn last-minute guest bookings with other clubs, or be invited to ride in individual events.

If you reach the sport's hectic Europe-wide uppermost echelons, like the current world champion, Mark Loram, a Brit, you can be contracted to separate teams in Sweden and dollar-rich Poland as well as the UK, thus facing four or five league meetings a week in three countries. Loram will also be defending his world title in the six-meeting Grand Prix series, which in June this year makes its Welsh debut at Cardiff's new Millennium Stadium.

At the very top, speedway is a lucrative life. At any level, it's a gruelling and unpredictable one of endless motorway miles; frustrating call-offs due to rain; expensive bills for engine tuning, maintenance and repair.

Rider income is governed by the number of points earned out on the track. Unlike many a big-name footballer, speedway riders don't get paid if they don't perform. It's hard. It's a calling more than a job.

Says Courtney: ''Scott had never shown any inclination towards speedway, although he'd gone to meetings with my brother, Sean, after I'd been nicked, at a time when Sean was still riding for Glasgow. But he really had no experience on motorbikes, unlike me at his age. I was always messing around on bikes in fields.

''Our family had moved up from Essex to Workington in Cumbria when I was 12. Until then, I'd seen speedway on the telly and enjoyed it, but I'd never been to a meeting. Then, in Workington, I could see the track from my bedroom window, and thereafter everything revolved around speedway.

''I was lucky to be encouraged into schoolboy moto-cross by older ex-riders and then allowed spins around the Workington track after meetings had finished. I rode on the beach. I spent all my time on the farm run by Steve Lawson's dad, at a time when Steve was just starting out on his way to becoming Glasgow's highest-ever points-scorer.

''I'd be helping Steve with his equipment, going to meetings with him. From the age of 15 I was writing my own sick-notes for school every day so I could be on a bike.''

But just as suddenly as Mark Courtney had emerged from being a 16-year-old wonderkid with speedway's short-lived Furnace Flyers, based in Barrow, so Scott Courtney was racing away with the Scottish junior championship in 1999, remarkably soon after having learned how to break his bike's rear-wheel traction in sufficently controlled a fashion to power it round shale-covered bends at reckless speed.

''It was a shame for Scott last year that he didn't actually get much riding done due to the various injuries he collected during his first season,'' says his proud dad. Broken collar-bones and fractured wrists are workaday nuisances to the speedway rider, incidentally. An iron-willed bunch of mechanised thrill-jockeys, they'll soldier on against conventional medical advice with everything from cracked vertebrae to broken legs.

Scott Courtney's own accumulation of assorted back injuries wasn't judged serious enough to stop him being sent off this past winter to learn his trade on a 10-week travelling circus-style American tour, riding in 12 ice-speedway meetings staged in indoor rinks between Texas and Arizona.

''I sent him off with #100 and my old bike, and told him it was a great chance for him to earn a living wage and pack in a lot of experience,'' says Courtney. ''Over there, they have six riders in a race, as opposed to our four. You really do learn how to get on in the first corner of a race.

''Having met Scott last week, I can tell it's been an education that will stand him in good stead when the British season gets going - mind, when I picked him up from the airport, he handed me back all the useable bits of my bike inside a holdall.''

Of course, it was thanks to Scott that Mark picked up the pieces of his speedway career with Glasgow. ''I'd been speaking on the phone about Scott to the Tigers's then-promoter, Brian Sands, and out of the blue he asked if I'd be interested in riding again.

''Now, after leaving Middlesbrough, it had been four years before I'd even gone to a speedway meeting, just to help Sean out a couple of times. I'd been busy building my own house and then I'd been working erecting timber-framed houses. And then in May 1997, I'd got nicked. But I had six days' home leave in April last year, and so I had a practice at the Tigers's track at Ashfield, vaguely thinking that maybe getting involved in speedway again might support me putting together an application for parole.

''Everything about speedway bikes had totally changed since I'd last ridden one.

''The engine is angled differently within the frame, and the frame itself is different, the cams are different, everything.''

Lo and behold, all these technical and design differences amounted to a vital difference for Mark Courtney: ''I found it easy to adapt to the new bike, and it was as though everything about the sport was brand new for me again. My problem is that I can get disillusioned very quickly, and once I've made a decision about something, I do it, no messing.

''That's what had happened at Middlesbrough in 1993. I like being in a winning team, alongside folk with a good, positive outlook. I like racing on good equipment, too. If I'm asked to ride a piece of crap, I'll give it a go, but while talent's OK, you need a good bike.

''I didn't have good bikes at Middlesbrough, and so I'd become disillusioned with the club, with speedway.''

Courtney freely admits that Middlesbrough had become disillusioned with him, too. ''It wasn't so much that I retired in 1993,'' says Courtney with a wry grin, ''it was more that the club banned me.

''How can I put this? There was trouble with a fire extinguisher in a hotel in Swindon after we'd had a meeting there. It caused a bit of damage and got in the papers, and I took the rap for it. Folk had been drinking; there was a mild bit of annoyance, and it was all intended as a laugh, nothing more.

''I meant just to give this bunch of pissed-up lads a quick blast, and then I discovered that there's some types of fire extinguisher that don't turn off after a quick blast and suddenly you've a roomfull of people staggering around in all this powdery stuff.''

We both laugh at this image, knowing that, as responsible adults, we shouldn't. Stuff sometimes happens to cloud life's issues, though. And of course it isn't always relatively harmless.

''A group of us were smuggling cannabis by sea from north Africa. How I got involved... well, I have to say that I was never forced into it, it was my own doing.

''Greed comes into it. An informant introduced us to an undercover Customs officer... and that was it. I put my hands up; I pled guilty; I went to jail.

''If you smuggle cannabis, there's the same kind of risk you run if you ride a bike: there's a good chance you'll crash and get hurt. And if you're busted for drugs smuggling, there's no option other than jail.

''It was my first time, and I got a hefty sentence. I was looking at three or four years and wound up getting six. With around 16 months spent on remand, I served two and a half years in serious prisons, with lots of bad people in them, first Durham and then Nottingham. I was in an open prison just for the final six months.

''I got my head down. I wasn't taken in by any idiots. But I met some decent people in prison. I looked after myself. I became the fittest I've been for years, playing so much tennis on a concrete surface in the wrong kind of footwear that I wound up with fallen arches.''

Courtney is currently out of jail on an 18-month licence which runs until October. He's unable to leave the country during that period and is bound to report regularly to a parole officer. Until that time, he's also liable to be re-imprisoned. But there's no doubting the sincerity of his conclusion about his criminal past.

''I've simple advice for anyone wanting to be a drugs smuggler: it's a dirty, filthy business - don't do it. Get a 9-5 job.''

Speedway is far from being a 9-5 job, but it's one that has surely re-kindled Mark Courtney's spark. It had seemed in danger of being extinguished by prison and by the attendent distingration of his marriage.

''The year I've had now since getting out has been the best year of my life - largely because, by chance, I met the girlfriend I'd gone out with 20 years ago, before my marriage. ''Speedway-wise, the only disappointing thing is that I took a while to get my bikes properly organised. I know that if I'd had the right equipment all the way through, not just in the season's last two months, I'd have been much better.''

Nevertheless, Mark Courtney ended his incredible comeback season on a demonstrably higher note than the one on which he'd left speedway seven years before. Each rider's points average is all-important in speedway, governing the composition of every seven-man team in a laudable bid to ensure parity of competition.

Twelve points is the notional maximum every rider aspires to (and never attains, no matter how good they are). Anything over nine points means a rider is rarely beaten by any member of the opposition. Any average over seven points means that you're one of your team's cornerstones, within the league's top 30 or 40 riders.

Having averaged just less than seven points in 1993, Mark Courtney posted an average of 7.09 for 2000. His first meeting, back in May, constituted an amazing start - despite an atypical opening race.

''I was leading my first race until the very last lap when I fell off - without that, I would have earned 12 points.

''I'm sure I can improve on my average in 2001, just as I'm sure everyone in the Tigers's team this year can improve theirs. I know that I've blown a lot of years through not capitalising on my talent - although I have to say that I've never thought I'm as good as people have reckoned.

''I'm 40 later in March, and it would be great to be a 10-point 40-year-old. My Tigers's team mate, Les Collins, is still a great rider at the age of 44. In the longer term, I'd hope still to be riding when my younger son, Jamie, who's 12, starts as a professional speedway rider in four years' time.

''I'm fit for my age. I keep an eye on my weight. I still love riding a motorbike. I look forward to racing - and racing competitively.''

Fittingly, Mark Courtney's return to meaningful competition in British speedway's Premier League has been mirrored by a major resurgence of interest in a sport which five years ago seemed to be locked into an irreversible spiral of decline.

In the seventies, it had been a staple of Saturday afternoon TV sports shows. In the eighties, speedway disappeared from TV, along with the sport's crowds and one track after another.

This has all begun changing with Sky TV's perceptive and exciting weekly live coverage of team racing in Britain's top division, the Elite League, plus its coverage of the Grand Prix series. There's an ongoing increase in the number of tracks, and Elite League crowd levels have risen.

Attendances aren't yet anywhere near major football level, however - not that that has deterred one life-long speedway fan with a major football connection from taking over Glasgow Tigers this season. Partick Thistle chief executive Alan Dick is the club's new co-promoter, along with businessman Stewart Dickson, taking over from the man who saved the club from extinction in 1998, Brian Sands.

''Sky's coverage has undoubtedly been a shot in the arm for the sport, although whether they've contributed enough in revenue terms is a different matter - it certainly doesn't compare to what Sky pay for football,'' says Dick.

Dick is well placed to make other comparisons between the two sports. ''Running speedway in a football-crazy city like Glasgow isn't easy. Speedway seems to work best in towns where it's the only professional sport, like Workington. Their top rider, Carl Stonehewer, is like a Pied Piper to all the local kids. In Glasgow, it's 'What's speedway?'

''Tigers's crowds last year averaged around 700, and we need to get that up to 1000. It's been officially stressed this year that every track needs to sharpen up its presentation of 15 heats, compressing them into a football-like 90 minutes.

''Speedway fans are much more understanding folk. Patient. Accommodating. They accept that there can be the odd duff meeting, and that if it rains, there'll be a delay. Football fans would be cursing and demanding their money back.''

Aye, it's a rare sport, speedway. It has to be admired for avoiding any sanctimonious concern over its image and allowing Mark Courtney his chance of rehabilitation.

That same spirit has allowed Falkirk teenager Derek Sneddon to make his way with Edinburgh Monarchs. Guided by two local policemen, Ian McNish and Tom McDougal, Sneddon was encouraged away from the slippery slope - stealing cars - and into the shale-slider's art.

Speedway: it's liberating.

Weather permitting, the 2001 speedway season re-starts today in Glasgow with a one-off training school hosted by an all-time giant of the sport - six-times world champion Ivan Mauger. Speedway hopefuls of all levels will receive meaningful coaching and advice for a fee of #100. Spectators won't be turned away.

Glasgow's Ashfield track, in Possil, is licensed for seven-day use, and it's hoped that No. 1 Tiger James Grieves will run training sessions throughout the season.

Ivan Mauger will still be present at Ashfield at 3pm tomorrow when competition proper begins with a clash between the Tigers and their old enemies, the Edinburgh Monarchs.

The Monarchs re-start their season at Armadale Stadium on Friday. In addition, there's action tonight, and every Saturday night, with the Berwick Bandits at Shielfield Park.