For many football supporters, especially of clubs like Chelsea that have enjoyed so much success in recent times, May is a month of anniversaries. A month to for us remember cup-winning outings to Wembley, Stockholm, Munich, Amsterdam and, further back, to Athens. Of clinching titles and promotions at Stamford Bridge, but also of trips to Grimsby, to Wolverhampton. (Old Trafford in 1970 and Bolton in 2005 are of course equally memorable, but were in April.)

These are successes that help define a football club, that stay in the memory for a lifetime. Social media has rightly been full of supporter memories and photographs of these great occasions, of the trip, the socialising, the match itself, the celebration – shared experiences that create an unbreakable bond among supporters. This welter of reminiscence has been especially useful this end-season, as it has slightly helped mask the realities and the pain of what has been, however you look at it, a season of unedifying farce for Chelsea Football Club. In years to come there will be no celebration and little fond reminiscence of the season just ended. May 2016 has not been an opportunity for the club to add to its trophy haul, to give the supporters another happy memory to file away for future basking. Far from it.

From the moment Romelo Lukaku stuck in his second goal in the Goodison Park FA Cup tie in mid-March, it has been clear that there would be no trophies for us to celebrate, no wonderful memories to file away for future use. The season died for Chelsea that moment, and the past two months has been a case of a team going through the motions, of loyalty unrewarded. Supposed main rivals Manchester City and Manchester United also underachieved in the league and, despite winning domestic cups, both have sacked their managers. Chelsea’s inability to exploit this situation, and indeed to contrive to have worse a season than either, should be a cause for serious embarrassment at all levels of the club.

The unwarranted lap of appreciation after the Leicester game unsurprisingly became a tribute to John Terry, a response from supporters suspecting their talisman was making his final appearance in a Chelsea shirt, albeit as a non-combatant. The subsequent agreement for a further season’s contract is clearly to be welcomed, as much for his influence off the pitch as his inevitably waning powers on it. As has been pointed out before, the post-Terry Chelsea are in danger of being as leaderless on the pitch as they sometimes seem to be off it.

Terry is the last survivor of the magnificent core of players that served the club so well for a decade or more, and the inability of the club hierarchy to replace their ability, charisma and winning mentality has resulted in a large flock of chickens coming home to roost at Chelsea. The grim reality seems to be that, without Terry’s leadership, not only are there a lot of roosting chickens but that many appear to be lacking their heads.

It is very hard for supporters to identify exactly why the past nine months have been so painful and exactly what factors resulted in the perfect storm of failure we have witnessed since August.

Complacency. Arrogance. Incompetence. Disloyalty. An irreversible breakdown in key relationships. A ludicrous array of individual errors. A collective loss of will and form. The ageing process. Being tactically and technically found out. A levelling out across the Premier League. Inept transfer dealings. An ill-advised pre-season schedule. Unwarranted owner intervention. The Carneiro saga. A dysfunctional hierarchical structure where players could complain to the technical director behind the manager’s back. Personal issues. There are certainly no shortage of theories and the reasons for Chelsea’s abject season will doubtless be the subject of books by journalists who may, or may not, be in-the-know. Probably the latter.

Celebrating Tottenham not winning the title, though pleasurable, is hardly the same as winning one ourselves. A double over Arsenal is all well and good, but has happened four times in eleven seasons so is hardly a shock. Analysis of the season thankfully now ended makes truly depressing reading, and helps highlight the size of the challenge that Antonio Conte has in front of him to turn the club around before the owner presses the ‘Next’ button. It is clear that this was Chelsea’s worst season for at least twenty years.

Consider the following statistics with regard to league performance:

Chelsea started the season deserved League Champions. In the past 50 years, only four teams have defended their title less effectively – Manchester City, Everton, Aston Villa and Leeds and each took years to effectively rebuild. Leeds never have. Nobody is saying Chelsea are going into terminal decline but bouncing straight back will not necessarily be as straightforward as some seem to think.

– Manchester City, Everton, Aston Villa and Leeds and each took years to effectively rebuild. Leeds never have. Nobody is saying Chelsea are going into terminal decline but bouncing straight back will not necessarily be as straightforward as some seem to think. The final position, tenth, is the club’s worst league position for twenty years .

. At no stage of the season were Chelsea higher than eighth in the league, so at no point were we in a European qualification place.

The appalling total of five home wins, the worst since the 1978/79 relegation season under Danny Blanchflower, when at least the club had the excuse of having to sell the best players because they were skint. The most home defeats for over twenty years . Just twelve months earlier, Chelsea had the best home and away records in the Premier League.

season under Danny Blanchflower, when at least the club had the excuse of having to sell the best players because they were skint. . Just twelve months earlier, Chelsea had the best home and away records in the Premier League. Only Bournemouth and Aston Villa conceded more home goals. In 2014/15 Chelsea conceded just nine home goals, this time we let in 30 .

. Chelsea ended the season 31 points behind deserved winners Leicester, their biggest gap from the top since the 1993/94 season, and achieved their lowest points total since 1995/96 .

deserved winners Leicester, their biggest gap from the top since the 1993/94 season, and achieved their . The least wins, and least points, since 1995/96 . The most defeats since 1997/98 . The fewest goals scored for sixteen years . The most goals conceded since 1996/97. The worst goal difference for nineteen years. The roll-call of shame goes on.

. The . The . The most goals conceded since 1996/97. The worst goal difference for nineteen years. The roll-call of shame goes on. Chelsea finished as fourth-placed London team , their worst capital performance for twenty years.

, their Since Roman Abramovich transformed the club, Chelsea have averaged 79 points a season. Given this, 50 points in 2015/16 can only be described as rampant under-achievement.

That statistical litany of underperformance underlines exactly how poorly the team performed last season. Given the resource and ability at the club, especially compared with the dog days of the late '70s and early '80s, there is a strong case for arguing it was Chelsea’s worst season for decades.

For all the affection felt for him, Guus Hiddink’s home record of one win in ten league games is diabolical, although it can be argued that when he arrived the die was already cast in terms of likely league position. He did indeed avoid relegation, though given the resources at his disposal this was hardly something to boast about. There never seemed the hunger to climb further than ninth or tenth.

No club has a right to win trophies every season and a harsh dose of reality may do some of our support a favour by firmly making that point. Even given this, though, the fall-away over twelve months, as spelt out above, is chilling. The worst season since the days of Craig Burley, Eddie Newton and Frank Sinclair, when the club were just starting to attract world-class players and building from a much lower base, cannot be acceptable.

Next season is clearly critical. Bouncing straight back into serious title contention under Conte will certainly not be easy, especially in a league enhanced by the return of Mourinho and the arrival of Guardiola. If Chelsea do recover quickly and are in there fighting for the league title, then 2015/16 can be written off as a blip, a best-forgotten freak. Should the decline not be addressed, and the inevitable summer purchases and sales not make the required difference, then the club would face a serious problem. Moving to the temporary stadium may happen in twelve months time, or there may be a delay until 2018/19. Whichever, selling tickets at Wembley or Stratford would be a lot harder if the club were not in Europe and were not seen as serious title contenders. The feel-good factor around the Stamford Bridge redevelopment would also inevitably be tarnished if the team went into medium-term decline.

Being generally optimistic I have to believe that under Conte, Chelsea will seriously compete for honours next season and qualify for the Champions League. Rooted in my subconscious, though, is a nagging fear that the problems at the club are deep-rooted and systemic, and will take more than a summer’s break, a disciplinarian manager and three or four new players to resolve. Let's hope my subconscious is worrying unnecessarily and that in twelve months time we can again start to store up memories from a season of success and achievement.

Tim Rolls is chair of Chelsea Supporters Trust, though writing in a personal capacity. He is a home and away season ticket holder, so his sense of disillusionment will hopefully disappear over the summer.