Worcestershire 163 and 155 for 3 lead Northamptonshire 202 (Keogh 57, Richardson 5-70) by 116 runs

There may be a day or two left of the campaign, but Northamptonshire are already celebrating what may just be the finest season in the club's history.

Essex's failure to secure the bonus points they required to stand any chance of overhauling them means that Northants are assured of promotion to Division One of the County Championship whatever happens in the rest of their match with Worcestershire.

With the FLt20 already secured - only the fourth trophy in the history of a club that played its inaugural first-class game in 1905 - and the club assured of playing in the top division for the first time since 2004, it is easy to understand why the chief executive, David Smith, declared it "the best year we've ever had". They only missed out on a YB40 semi-final due to run rate, too.

Perhaps 1976 was better. That year Northants won the Gillette Cup and were second in the County Championship - long before the days of two divisions or a financial divide between the top and bottom sides - but, whichever way you look at it, 2013 will be remembered as a golden year in the history of a club that has generally been content to live in the shadows.

It is the contrast with last year that is so remarkable. Not only did Northants finish second from bottom of Division Two in 2012, they hardly won a match in limited-overs cricket. Across the three competitions, no side won fewer games. Spectators stayed away in their droves.

As a result, they changed their captain and their coach. David Ripley, the wicketkeeper when Northants last won a trophy in 1992, actually replaced David Capel midway through the 2012 campaign but it was only this year that he had the opportunity to instil his own values upon the side. Stephen Peters replaced Andrew Hall as captain of the first-class side and Alex Wakely became captain in the limited-overs formats, deputising in the Championship side when Peters was injured.

Hall, relieved of the burden of leadership, rediscovered his form as a player and emerged as their "standout four-day performer", in the words of Ripley. No one in the side has scored more runs than Hall's 909, while he has also taken 35 Championship wickets.

The club also recruited wisely. Steven Crook, arguably the signing of the season, was brought in from Middlesex to add pace with the ball and ballast with the bat, while Azharullah was signed from league cricket and Trent Copeland as overseas player. They have so far claimed 113 Championship wickets between them; only Lancashire have taken more bowling points than Northants in the division.

The batting was even stronger. No side in either division can match their 54 batting bonus points and, with 15 men having contributed half-centuries, there were times when a batsman as competent as Copeland, who has scored a first-class century and gone in as high as No. 7 in Australia, went in at No. 11.

But there is more to this improvement than strong batting and bowling. Northants have also instilled in their side a unity and spirit that has seen them overcome two defeats against Lancashire - the only side that beat them and the only side they admit were better than them - and the inevitable stresses and strains of a long county season. The split captaincy idea has resulted in all formats benefiting from increased energy and time for planning, and the momentum of success in all forms of the game has proved self-perpetuating.

Perhaps most pleasing is the emergence of some young players at the club - the likes of Olly Stone, Rob Newton, Rob Keogh, Ben Duckett, David Murphy and even Wakely - who could go on to form the basis of a strong team for a decade to come.

If you really want to pinpoint the change in fortunes of this club, you probably have to go back to January 2012. That was when a new chief executive, David Smith, was appointed and when the ambitions of a club that had seemed content with a supporting role were overhauled. It was Smith who sacked Capel and appointed Ripley and who had the energy and vision to see how the club could regain the relevance it once had in its local community. His job is not complete, but he has made a fine start.

Not only have Northants' on-field performances improved in the last 20 months, the club have bought the ground on which they play, improved their facilities and begun an economic development that will, in time, see their income grow by 30% or more. Only last Sunday, 13,000 people attended a Madness concert at the club, which will have earned Northants around £75,000.

Northants have come close to promotion before. In 2009 and 2011 they missed out by a single point and there were times over the first couple of days of this game when they feared history would repeat itself. Alan Richardson, hailed by Ripley as "still the best bowler in this division" produced a characteristically excellent spell of seam bowling in the morning to reduce Northants to 157 for 8 before Keogh and Murphy helped them secure a bonus point. Richardson, whose 14-over spell was a terrific effort for a 38-year-old, fully deserved his fifth five-wicket haul of the season and 23rd of his career.

In the end, though, Essex's shortcomings rendered the outcome of this game irrelevant to the promotion issue. Quite why Essex would invest in high-profile signings like Monty Panesar and Gautam Gambhir in the finals weeks of a season and then not select senior players such as David Masters, Reece Topley, Owais Shah and, though fitness was a factor, even Ravi Bopara for a game that could have earned them promotion, is anyone's guess. But the achievement means plenty to Northants.

"We're not Manchester United," Ripley said, "but to the 100 people who clapped us off the pitch and all the others following this game at home, this results mean a lot. I had plenty of doubts that we would get here so it's just a relief that we have.

"We know that it will be tough next year. But we've taken heart from the fact that Yorkshire have gone from runners-up in Division Two to runners-up in Division One in a season and the fact that we've been good in all formats and near the top of the Championship table since the first game shows we've deserved this."

George Dobell is a senior correspondent at ESPNcricinfo