Maro Itoje is a special player who could really take it to the All Blacks on the Lions tour.

OPINION: I first played in what was then the Five Nations way back in 1973, and first coached a team in the competition in 1986. I have watched it develop and evolve over time and have never been less than fascinated by it.

I can honestly say, though, that it has been quite some years since I have looked forward to a tournament as much as I have this one.

In my opinion, this year has all the ingredients to be one of the most intriguing, hard-fought championships we have ever had.

REUTERS France are the dark horses for the Six Nations after strong performances against New Zealand and Australia.

Six genuinely competitive teams - Italy, perhaps, still a rung or two below the others, but remember, they beat South Africa a couple of months ago and no one will relish playing them, particularly early in the tournament; the new tackle directives, as I have written in these pages before, I believe could lead to a faster, more open game; the incentive of bonus points, new this year. Again, a positive development in my opinion, with nearly every other competition in the world using that format.

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And of course, this year's Six Nations has an extra dimension to it. Why? Because it is a Lions year. Not only that; it is a Lions tour to New Zealand this year.

GETTY IMAGES Vern Cotter has done a great job turning Scotland around.

New Zealand tours can define a player's career, his legacy; make him a legend. Win against the world champions and that Lions team will go down in history. As much as they will all try to focus on their performances, it will give an extra frisson to the individual clashes we will witness over the next seven weeks. Whether it is Rory Best going up against Dylan Hartley, or Finn Russell against Dan Biggar, everyone will be looking to make a point to Warren Gatland.

It is going to be a thrilling ride and it really is a difficult one to call. Based on the autumn internationals, England and Ireland have to be the favourites, with France, Scotland and Wales fighting for third place.

But the Six Nations is utterly unique in the way that it is structured. It is not a 'home and away' format like the Rugby Championship. You play each other only once, and the way the fixtures fall can have a huge effect on the overall outcome.

The uneven spread of three home matches and two away, or three away matches and two home, can decide the outcome. That might not be totally fair, but it gives the tournament a unique flavour.

If pushed, I would say England are my favourites, because you cannot deny the quality of what they did last year, going 13 games unbeaten (14 in total if you go back to Uruguay in the 2015 Rugby World Cup). They have depth, they have leaders, they have confidence. But they also have injuries. I think Eddie Jones is going to have a look at Maro Itoje at six, given Chris Robshaw is out, and it is going to be fascinating to see how he performs in his second international season, now that his opponents know what to expect from him. Itoje is a special player, one of those you can really see taking it to the All Blacks.

Ireland also face England at home, which has to count in their favour. So I don't think it is necessarily going to be a grand slam year. Whoever wins, it is going to be close.

Both England and Ireland have exceptionally difficult first games; France at home and Scotland away respectively. England then go to Wales in the second game, which is traditionally an extremely tough fixture. What helps England is the fact that Ireland also have to go to Cardiff - and on a Friday night, too.

I would go so far as to say the championship will be decided in Cardiff. Wales were not at their best in the autumn. Of the home nations, they are the ones searching for their identity. But you cannot underestimate them. If they win those two matches all bets are off.

Their back row is still world class. If Sam Warburton, Justin Tipuric and Taulupe Faletau are all available, that is as good a back row as you could field. Alun Wyn Jones taking on the captaincy could really free Warburton up to play his natural game.

You look at every weekend and there is a match which could go either way. Scotland are as good as they have been for a decade. You have to give enormous credit to Vern Cotter. All through the team they have real solidity; front row, second row with the Gray brothers, back row.

Greig Laidlaw has an excellent kicking game at nine. You have Finn Russell, who has now proved for Glasgow that he can control a game, at 10; Tommy Seymour, Duncan Taylor, Huw Jones, Sean Maitland, Stuart Hogg. For the first time in ages, it feels as if Scotland have real depth and options from the bench.

France are the dark horses. They have settled under Guy Noves. He is clearly keen on an offloading game but France went too far with it last year. I noticed that against New Zealand and Australia in the autumn they had cut down on that. If the offload was not on they would take the tackle.

I am intrigued by their back row, which basically features three No 8s in Kevin Gourdon, Loann Goujon and Louis Picamoles, and a very young second row. A lot will depend on the mobility of these big forwards.

Italy are more than capable of giving the bigger nations a bloody nose. As they proved by beating South Africa in the autumn internationals, they represent a stern test, particularly in Rome and particularly in the first two games of the championship. It is not a nice place to start for Wales.

The start is everything in a five-game championship. Win your first match and you have momentum. Lose and you are on the back foot. It is very difficult to recover.

There is still nothing like the Six Nations in world rugby. We can argue over the relative strengths and weaknesses of the northern and southern hemispheres. I can accept that their skill levels are still ahead of ours. But this is the most intense tournament in the world. I think southern hemisphere refs are sometimes caught out by the intensity.

Every fixture has its own identity. It has built up over generations. It is not just the match, it is the weekend, the atmosphere. Every venue has its own.

Some complain that it is all becoming gimmicky now, with the Six Nations dancing to the tune of TV executives, with Friday night kickoffs and staggered match times.

I draw the line at playing five matches on five consecutive weekends. That was clearly the brainchild of someone who has never played or coached at international level. But tell me that final day from a couple of years ago, when Ireland ended up winning despite England's last-gasp effort against France, was not one of the great days of rugby.

I have a feeling we are in for more final-day drama this year. It is hard not to imagine that the Ireland v England finale will have the title riding on it.