The one critical factor for the rest of the season that will carry United to its 13th Premier League title in its 20-year history is the partnership between Paul Scholes and Michael Carrick.
United have won all ten Premier League matches they have played together since Scholes came out of retirement. It is no coincidence that during that time United turned a five-point deficit into an eight-point lead.
Some people have even touted Scholes as Player of the Year, but my choice would be Carrick. Little more than four months ago, the Ginger Prince was languishing in retirement, and Carrick, in an injury-hit season, was getting his usual quota of disproportionate criticism.
And yet some people are even talking of the pair being England's central midfield in Euro 2012!
Sir Alex was probably being over-protective in resting Scholes against Wigan—and he paid for it as the Latics turned in a master-class.
Injuries permitting, the duo will finish out the season and is the main reason why I'm confident United will prevail.
They are just one pairing in United's most settled team that can carry us to glory yet again, and there are plenty of other reasons to be confident.
OK, so City have players with great individual ability, most notably Aguero, Silva, Hart, Yaya and Kompany.
But United have a series of partnerships that will see them home. Apart from Carrick and Scholes, there are:
Ferdinand & Evans
So, hands up all those who thought that Vidic's season-ending injury would mean United's title chances were gone?
Especially with Jonny Evans getting such a poor press and not having fulfilled Sir Alex's unyielding belief in his ability. Also, Chris Smalling in only his second season and Phil Jones coming in raw. Then there were the injuries...again...
Ever since Sir Alex advised Rio to make allowances for his lost yard of pace, he has been a rock in United's title defence. But Jonny Evans, who had a dreadful game against City in the 6-1 hammering, has come back to be one of the best central defenders in the League.
This season they have played 16 games together in the League, winning 14 with one draw and one defeat, conceding only six goals.
Rooney & Welbeck
OK, so they led the line when City won 6-1, but of the other 14 games they've started together, they've won 13 and drawn one.
They have an excellent understanding. Welbeck is very athletic and wins the ball in the air but is no mug on the ground. Rooney has scored 31 goals this season despite not playing that well.
Hernandez is the unlucky one, having "second season syndrome," but he has had injuries. Maybe defenders have worked him out, but he's working harder and covering more ground now. He'll be back, but he really must cut out the offsides.
Nani & Valencia
Ashley Young has done well in his first season and looks very versatile. Nani prefers to play on the right, but Valencia has been on fire since his return from injury.
Believe it or not, they've only started as a wing pair eight times this season, but they've won seven and drawn one.
These are the pairings that should see United home.
Manchester United won the first-ever Premier League title in 1992-'93 and have won 12 in total over the almost 20 years it has been in existence.
During that time they have never been outside the top three, and they've only finished third three times. They know what the back end of the season feels like.
And the common factors are, of course, Sir Alex Ferguson and Ryan Giggs, who have experienced every one of those title battles. Paul Scholes has known all but one of them.
Every year, the squad has a mix of plenty of experience and some younger players who are either coming into the squad or developing. This gives that enviable combination of energy and calmness. Look at the effect Scholes has had on the team since his return. Together with Carrick, they are not flustered in the middle.
But it's not just the players on the pitch that have been here so many times before. Old Trafford has a constant flow of former players who also know what it's like at "squeaky bum time"—players like Bryan Robson, Andy Cole and Gary Neville, who are all club ambassadors.
In truth, United have lost the odd title they should have won, but they especially know how to come from behind, as they did when overhauling a 12-point lead by Newcastle in 1995-'96. This was the season of Kevin Keegan's most famous managerial rant of all time after Fergie wound him up.
And this is another key factor with so few games to go. Sir Alex knows how to weather the pressure but also how to get under the skin of, especially, managers and players who've never won the Premier League before.
Is it my imagination, or does Roberto Mancini look significantly older than he did a year ago? Surely he has much more grey hair than when he arrived at Eastlands?
Maybe it's the stress of managing volatile and mercurial personalities like Balotelli and Tevez, but in this press conference he doesn't look like he's sleeping well.
He's definitely trying to play mind games with someone by conceding the title. Is it to gee up his players, or is he trying it on with Sir Alex? In the latter case, he cannot win unless City do indeed win the title.
Has it taken the blowing of City's nine-point lead and an eight-point deficit for them to throw all caution to the wind, resulting in the thumping of West Brom and Norwich in a few days?
Sir Alex is being canny as usual, refusing to accept the inevitability of a title win.
Failing a City slip-up at Wolves, it seems certain that the Derby at the Etihad will have at least temporal significance, even if it is just for the summer's bragging rights. And yet even if City win, United will still have their destiny in their own hands provided they can beat Everton.
Yes, Mancini has won trophies in Italy, but this is the Premier League, with the intensity of competition, where any team can beat any other on the day, as Wigan have shown in a glorious few days.
What is certain is that neither manager can afford complacency for himself or his team.
Ferguson wins on points.
Chicharito can't get a regular start, and Ji Sung Park can't even get on the bench.
So, although United still have six long-term injuries and City have none, the former still have great strength in depth.
Part of the reason is that Sir Alex has faith in so many of his players, including young ones who are only just beginning to establish themselves in the squad.
In recent games, both Cleverly and Pogba have not only been on the bench, but have also got on the pitch. This is nothing to do with injuries, because Sir Alex has had plenty of fit players to choose from. He has chosen to rest Scholes, for example, against Wigan, but that backfired.
Even with things so tight, he is eager to give his future young stars experience of what it is like at a time of such intensity. Even losing is a critical learning experience when United go out and expect to win every match.
As usual, Patrice Evra has featured in virtually every Premier League match this season, with 33, but none other has played even 30 matches. Only nine have played 20 or more, compared to ten for City.
When you factor in the European and other matches, however, every one of City's first-choice team has played 33 matches or more, with the key players being Hart with 47, Kompany 38, Silva 43, Aguero 44 and Yaya Toure 38 so far. In addition, the latter played six games in the African Nations Cup.
In total, City's first-choice team has started an average of 35 games. For comparison, United's first-choice team (in the absence of Vidic) have started an average of less than 30 games all season.
On the other hand, City have used 23 different players in the Premier League and 28 in total, while United have used 29 and 35.
A couple of months ago, David Silva would have been voted Premier League Player of the Year. Then he disappeared. Hardly surprising, as he began to look exhausted.
Mancini may have been canny in resting him for the title run-in, and he did have an injury, but City missed him, as it showed this week when he was back running the show.
Yaya Toure has also looked a little jaded, whereas Paul Scholes at 37 looks as fresh as a daisy.
It's not just about physical fatigue, of course, but players are training almost every day that they are not playing, and Premier League regimes are among the toughest in the world.
It's also about mental fatigue. This shows particularly in defence as the pressure is on, because defence is based on the organisation of the whole team, not just the five at the back.
City have conceded eight goals in their last seven matches, while United have conceded only one.
In the middle of the title run-in, Sir Alex took the entire first team squad to St. Andrews for a couple of days to play golf. That shows tremendous faith in his players and a unity in the squad. It has showed since they returned.
OK, they lost at Wigan, but that was an anomaly. If they hadn't had two diabolical decisions against them, the Latics would have beaten Chelsea, United and Arsenal in the space of a week—and deservedly so.
That goal was the only one United have conceded in six weeks and one of four in the last ten weeks of the league.
For much of this season, this has been described as the worst United team for years, and yet they may win a 20th title and 13 in 20 years. Given the extraordinary catalogue of injuries, that can only be put down to team spirit.
Only two or three United players would make a team of the year, and probably only Scholes and Rooney could now be counted as genuinely world class, so it must be the team collective that has carried the day. This can best be summed up by the matches United have won by an odd goal or in the dying stages.
In fact, the best example of all must surely be the stunning comeback from 3-0 down against Chelsea.
On the contrary, apart from an apparent drawing together since they fell eight points behind, the City squad can hardly have been likened to a tightly knit team by other than City supporters.
If you want to avoid red cards, maybe it's not the best idea to draw attention to yourself.
Mario Balotelli is an enigma. It has been suggested that he may even have to see a psychiatrist to iron out his personality flaws.
OK, he had a troubled childhood beyond our comprehension, yet when he wears a T-shirt saying "Why Always Me," he is not only attention-seeking, but he clearly doesn't get the point that he is making.
Recently, Mancini revealed he almost substituted him after five minutes in one match, and earlier in the season he was substituted having been brought on as a sub himself!
Apart from gatecrashing Claudio Ranieri's press conference in Italy and setting off fireworks in his home, he is a walking disaster area. How on earth Mancini hasn't had a heart attack is a miracle.
And then there is Carlos Tevez.
Nobody could persuade me that such goings-on at City haven't been doing the heads in of the team collective. If City don't win the title, Balotelli may get more attention than he wants from his colleagues, who will be divided in their opinions about Carlos Tevez, also.
Then there are the players who either want to leave or are going to be sold.
These are the sort of diversions you don't get at United. It seems light years away that Wayne Rooney threatened to leave...
Who's this chubby little South American?
With Balotelli so unpredictable, Mancini has had no alternative but to turn to Carlos Tevez, who is certainly overweight and surely can't yet be match fit.
It was hilarious when Patrick Vieira suggested that United were desperate when they brought back Paul Scholes. As Sir Alex said, how desperate do you have to be to play one of the best English midfielders ever? Anyhow, Paul was kicking the door down to come out of retirement, because he was so bored.
Scholes has been the main reason why United have turned the tables on their cross-City rivals, and he is also what will carry United to a 20th title.
There is no getting away from the fact that Tevez is a very talented—indeed world class—player, as his performance against Norwich showed.
With Dzeko disgruntled and probably on his way out, Mancini will probably have to rely on his pair of Argentinian strikers, David Silva and Yaya Toure, to carry them through the rest of the season. Some of the other players seem to have gone off the boil, and others are obviously fatigued.
In their style of play also, surely City will have to play out and out attacking football, as they have to win every match and still hope for two United slips. That will leave them more exposed at the back, which has been their downfall since the turn of the year.
Meanwhile, you can bet your life that Sir Alex would take four 1-0 wins.
Alan Pardew would be my choice for Manager of the Year.
What he has achieved at Newcastle has been little short of a miracle. It's not just the way they've played, or the team spirit he has engendered. In the time Kenny Dalglish has spent £113 million to be 33 points adrift of United, he has spent less than the fee he received for Andy Carroll to take his team to the verge of Champions League qualification.
And City have to visit them before the end of the season. So, whatever happens at the Etihad in the Manchester derby, there is still a roadblock lying in wait at St James Park (I refuse to call it the SportsDirect.com stadium).
They've only been beaten twice all season at home; they've won their last five matches; and Demba Ba can't even get into the team at the moment.
With every chance of making it into the Champions League, they won't lack any incentive to beat City in the penultimate match of the season—if United haven't won the title by then.
The match at the Etihad on 30 April may be the match of the season. United's slip-up at Wigan has guaranteed that the title won't be won before then, but it could be won on the day.
The Premier League has already decided the trophy won't be presented on the day, but will we see a repeat of the guard of honour that United gave to Chelsea, if they have a seven- or eight- point lead at the end of that match?
The FA Cup match at City in January showed just how motivated United can be—and make no mistake, they will treat every match as a cup match until the end of the season now.
So, the City supporters may say, what about the 6-1 drubbing? Frankly, United brought that on themselves, starting with Jonny Evans being asleep while Balotelli scored the first goal and then getting sent off. That's not going to happen again.
Prediction: United win and let the celebrations begin.