Steve Jones, the new world record holder in the marathon, is like the legendary Broadway actor who worked 15 years to become an ''overnight success.'' The 29-year-old Welshman's name may not yet be familiar to the public, but he's been out there putting in the miles on tracks, roads, and countrysides ever since his debut as a teen-age cross-country runner in his native Wales back in 1970. And they all paid off this fall in Chicago when he broke Alberto Salazar's world mark with a time of 2 hours, 8 minutes, and 5 seconds.
The way Jones won the eighth annual America's Marathon - with a ferocious kick in which he averaged 4:45 per mile for the last seven miles - was significant too. That's track-running time; in fact his 29:38 clocking for the final 10,000 meters would have been a world record at that distance in the 1940 s. To run so fast after putting in 20 miles is a truly phenomenal feat - indeed there had never before been a comparable finish in a marathon.
Jones's victory and the manner in which he achieved it thus emphatically underscored a growing trend in which runners with track and cross-country backgrounds are taking over the longer races - even the 26-mile, 385-yard marathon. It also added to the impressive string of marathon successes by British runners this year, including Geoff Smith's victory in Boston, Charlie Spedding's win at London and bronze medal in the Olympics, and Irishman John Treacy's silver at Los Angeles. The two elements are not entirely unrelated, since these men also have come only recently to the marathon after spending most of their time competing at much shorter distances.
''I really do think it's because basically we're all track runners,'' Jones said when asked for his explanation of the recent British successes. ''We train for the track, and our speed threshold is higher than that of marathoners. A top marathoner can run sub-five-minute miles for 20 miles and be able to keep on around that pace; we can do it and then pick it up.
''The thing people wonder about track runners is whether the endurance is going to be there - but as you can see, it is. Our mileage in training may not be as high as that of a marathoner, but we have 10 years or so background in running, and all those miles over all those years have built up our endurance too.''
Jones feels, in fact, that one reason Salazar's recent marathon efforts have not matched his spectacular successes of 1982 may be - ironically - that he began training too much like a marathoner.
''I think you'll find that his fastest and best marathons came not that long after he set the US record in the 10,000,'' he said. ''In the last two years, though, he concentrated on miles and neglected track work. I think this year you'll see him go back to track work.''
Jones, a corporal in the Royal Air Force, grew up in Ebbn Vale, South Wales, and initially got into running at age 15 through an Air Training Corps youth program. He had never done any formal training, but one day some friends were going to a cross-country race for ATC cadets and talked him into coming along - and of course, in the usual storybook fashion, he did better than any of them. These cadet meets four times a year were his only running experiences for the next few years, but by the time he joined the RAF at age 19 he had developed an ambition to try for a running career.
''It was something I had had some success at, and you know how youngsters revel in success,'' he says. ''I wanted to take it as far as I could.''
Jones certainly wasn't any ''overnight success'' at that time. He learned right away that it was a lot different running against people who had been in regular training than it had been against cadets coming out to meets four times a year the way he was. But ''you quickly adapt,'' he says - and eventually he started making a name for himself in running circles.
The first breakthrough came via a seventh place in the 1976 Welsh national cross-country championships - despite which he was bypassed in the selection of 13 runners for the national team.
''I guess maybe they thought I was a flash in the pan,'' he said in an interview during a recent stop in Boston to compete in a benefit race in nearby Braintree, Mass. '' I was disappointed, but I just said to myself, 'Next time they'll have to pick me.' I set a goal right then to win the race the next year - and I did. In fact I've won it every year since then except one.''
Of course Wales is a small country, so this in itself doesn't mean too much, but by 1980 Jones had moved up enough to be a strong contender for the British Olympic team. He went for it in the steeplechase but finished fourth, beaten for the third and last spot by just a few seconds.
''It was tough,'' he says, ''but I didn't spend much time thinking about it. You can't sit around and be disappointed. There's so much more to achieve.''
Over the next few years Steve had some good international races, topped by a third in the world cross-country championships last March. He also made the 1984 British Olympic team in the 10,000, going on to finish a very respectable eighth in Los Angeles.
As for the marathon, Jones had never even run one when he accepted an invitation to the 1983 America's Marathon in Chicago - primarily, he says, because it meant a nice expenses-paid trip to the United States for himself, his wife, Annette, and their two young boys.
And why did the organizers want a track runner who had no ''name'' value?
''I think I had built a reputation for giving a full effort, for making it a race,'' he says. ''I'm not the kind of guy to hide in the pack. I don't mess around. I think they said, 'If Jonesy is in the race it'll be a good one - whether he wins it or not.''
Unfortunately, Jones injured his ankle the day before the event. He tried to run anyway, but had to drop out at 16 miles. The Chicago people appreciated his effort, though, and invited him back this year - which turned out to be a pretty smart move on their part!
And what's ahead now for Steve?
''I'll run in Chicago next year,'' he said, ''and I'm thinking of doing one other marathon in the spring. There are the European and world cross-country championships too, and I also want to continue my track career.
And is he looking as far ahead as 1988 and the next Olympics?
''Everyone else seems to be, so I might as well,'' he said with a smile. ''Originally I thought about the 10,000 again. Now I'm thinking marathon too. But I will pick one - I won't try to do both.''
Finally, what about the chances of breaking his own world record?
''I think I can run faster,'' he said. ''I'm not saying how much. Maybe just a second. But I think under the right conditions I could break it - and so could a number of other people. All 10,000-meter runners, I might add!''