Here's a question as you ponder the Premier League title race that refuses to obey logic: can you remember a season when the following took place? Arsenal blew their title hopes by losing games to extremely humble opponents, including one defeat to a club now in League Two. One of the key title challengers then, like Chelsea now, failed to take enough points off their biggest rivals. And Manchester United did not play a league match for 26 days. The last clue is the giveaway, it was 1999-2000, when Sir Alex Ferguson's team returned from the ill-conceived and short-lived World Club Championship in Brazil to find the Premier League title still unresolved.
In response they lost just one of their remaining 19 league games (to Newcastle, remember when that could still happen?) and won the title by an imperious 18 points. Everyone said their break in Brazil had given United fresh impetus to push on and win the league. Arsène Wenger went one further, saying darkly, "The league had been set up for United from the start."
This year, United have a break coming up, albeit shorter and earlier in the season than in 2000, and how they respond when they return could prove decisive. With Liverpool on top by a point after 14 games, United will certainly not leave for Japan fearful of being badly adrift when they return.
Chelsea have taken just one point from their other three big rivals (in 1999-2000, Leeds, who finished third, took just three from 24 against the big four).
What follows is an attempt to make sense of the state of play at the big four this season. And that League Two team that Arsenal lost to eight seasons ago? It was Bradford City, currently second in their division. Suddenly Arsenal's recent defeat to Hull does not look so bad.
Without question, the team to beat. Six points behind Liverpool and with a game in hand, the performance against Manchester City looked much more impressive in comparison to defeat at Arsenal and that draw against Aston Villa. A personal theory is that the trip to Japan could yet have a profound effect on them.
They are away for nine days – travelling and playing in total – which is less than the World Club Championship in January 2000 but more than if they were playing the old-style one-off Toyota Cup game.
Ferguson's ideal scenario is that Liverpool and Chelsea lose their games in the round of fixtures played while United are in Japan. It is not beyond the realms of possibility with Liverpool away to Arsenal and Chelsea away to Everton. When they returned from Brazil in 2000, United drew at home to Arsenal leaving them three points behind Leeds with a game in hand. They cruised to the title after that.
Almost nine years on, the basics have not changed that much for Ferguson. He has the best squad in the Premier League because he buys the best players. Michael Carrick has been one of the most influential performers since coming back from injury and Rafael da Silva at right-back is something to be treasured. Of course, it could all be undone by an injury crisis, like the one that almost derailed the 2002-03 title-winning season, but United seem better equipped to roll with the punches.
If they come back exhausted from Japan, however, the story might be different. Two games in four days await them against Stoke (away) and Middlesbrough (home). They need to win those to stay in the pack.
Prediction: Champions, and wondering why it was so easy.
Whatever the merits of Luiz Felipe Scolari's attempt to play better football, his team are not as good – man for man – as the side which won the club's two titles in 2005 and 2006. Scolari is playing with wingers just the same but, for instance, you would take the Damien Duff and Arjen Robben of 2004-05 over Florent Malouda and Joe Cole. One of the great problems at Chelsea is that, in terms of real quality, they have struggled to maintain those early Roman Abramovich-era standards.
John Obi Mikel will be a great player but he is not yet at the level of his predecessor Claude Makelele. The injuries to Ricardo Carvalho have meant that there has been no settled partner alongside John Terry, like William Gallas was in the title-winning years for Chelsea. They have suffered with Carvalho, Michael Essien and Joe Cole out with injury and Didier Drogba injured then suspended. And there are deeper problems.
Watching Eidur Gudjohnsen wander around the pitch at Stamford Bridge long after the fans had gone home on Sunday you were reminded of the time when Chelsea really did have a second option in attack. Gudjohnsen was good at unlocking a deep-lying opposition defence at home and most defences that come to the Bridge are deep-lying. Amr Zaki and Karim Benzema are possible options. Gudjohnsen would be even better.
Prediction: Second, and promising big changes in the summer.
There was a telling moment against West Ham at Anfield on Monday night when David Ngog stripped off his tracksuit and the fourth official fiddled with his dot-matrix board. On the pitch you could see Robbie Keane say to no one in particular, "Bet it's me". He was right. It's a poor state of affairs when the £20m striker is not judged a better bet than the kid who scored no goals for Paris St-Germain last season.
Keane is the latest in a long line of Liverpool strikers who have found themselves at odds with Rafael Benitez. It started with Michael Owen and continued through Djibril Cissé, Peter Crouch and, to a lesser extent, Dirk Kuyt. Benitez does not play them in positions where they are able to do what they do best. Liverpool's problem of late has been failing to score against Fulham and West Ham. Benitez's major blind spot is how he treats his strikers who are not Fernando Torres.
With Torres fit, Liverpool are a decent outside bet for the title; without him they have got no chance. They could sneak through if United and Chelsea disintegrate spectacularly, but what are the chances of them both blowing up? Even top of the table they have done nothing to demonstrate they are better than third.
Prediction: Third, and running out of excuses.
Back in 2000, the issue with Arsène Wenger was the improving of his defence (he bought Sol Campbell the following summer) and the conversion of Thierry Henry from winger to centre-forward (it's fair to say that was an experiment that worked).
This time around the defence is still the problem with the victory over Chelsea concealing the fact that Johan Djourou has conceded a penalty and scored an own goal in his last two games.
There are outstanding performers in this Arsenal team, just not always in the key positions. A personal view is that their best player this season has been Gaël Clichy who – that slip against Spurs aside – offers so much in defence and attack.
The problem is that he is a left-back and not a centre-midfielder or a striker. In 2000, Arsenal were also judged over-reliant on Tony Adams to, as he said then, "rattle a few cages". They have someone like that now, although Gallas' cage-rattling days are probably best left behind him.
Prediction: Fourth, but as ever, facing the future with optimism.
Big Four dossier
Man Utd 14/28/+16
How injuries have affected them:
Martin Skrtel (knee) has been out since October, Sami Hyypia missed a fortnight while Fernando Torres (both hamstring) missed a month from early October and will be out until Christmas. Philip Degen has suffered rib and metatarsal injuries while Steve Gerrard (groin) has missed a handful of games.
Michael Essien (knee) has played just two games and will not return before March. Didier Drogba (knee) has missed 14 games this season while Ricardo Carvalho (knee and thigh) has sat out 15. Joe Cole (ankle/foot) should return soon, while Michael Ballack (calf) has missed 12 games.
Owen Hargreaves (tendinitis) is out for the season, Paul Scholes (knee) and Wes Brown (ankle) are out until Boxing Day, having both missed sizeable chunks of the season. Gary Neville (groin and ankle) has played just 11 times this campaign.
Eduardo has been out since February with an ankle injury. Tomas Rosicky (hamstring) has also failed to feature this campaign. Abou Diaby (thigh) missed 12 games, Samir Nasri (knee) sat out a month while Cesc Fabregas (hamstring) missed two weeks. Theo Walcott dislocated a shoulder last month and is not due back until the new year. Amaury Bischoff (groin) has featured just once while Mikael Silvestre (hamstring) missed two months. Emmanuel Eboué has been out for a month with knee trouble.