SCOTLAND

Key player:

FINN RUSSELL

Age: 24 Position: stand-off

Club: Glasgow Warriors Caps: 22

The team’s principal playmaker remains inconsistent, but as he grows in experience he is learning to temper his natural attacking urges with more judicious decision-making. Having Gregor Townsend as his coach at Glasgow has been a vital part of Russell’s development, and the fact the partnership will continue when Townsend takes over as national coach next summer can only be a good thing.

Coach: Vern Cotter is in his last Championship before returning to club coaching in France, and is determined to go out on a high. He found it tough going at first, losing every match in the 2015 tournament, but by last year he had succeeded in stamping a distinctive and attractive style of play on the squad and was rewarded with victories against Italy and France.

Form guide: Those two wins last year followed two narrow defeats before the Championship ended with a heavier loss in Ireland. In the autumn, Scotland suffered an agonising single-point loss to Australia just as they had done in the World Cup, then recorded solid victories over Argentina and Georgia.

Strengths: An attractive attacking outfit, they have more strength in depth than for some time, particularly in areas like the centres and back row. They are also far stronger up front than they have been for some time, enabling them to play a more versatile game rather than needing to steer the ball away from the pack.

Weaknesses: The loss of WP Nel for the whole championship and Alasdair Dickinson for at least part of it has exposed their lack of options up front. Allan Dell and Zander Fagerson will cover at loosehead and tighthead prop for Dickinson and Nel respectively, but their inexperience could be exposed by some teams.

Prediction: third

IRELAND

Key player:

CONOR MURRAY

Age: 27 Position: scrum-half

Club: Munster Caps: 53

With stand-off Jonny Sexton’s match fitness in doubt, the No 9’s already important leadership role will be enhanced further. Just as useful in clearing his lines as he is in initiating attacks behind an advancing pack, he is also adept at getting under the skin of the opposition.

Coach: Joe Schmidt took up the post in late 2013 and won the Six Nations at the first attempt then retained the title in 2015. Under contract until 2019, he presided over last autumn’s historic win over the All Blacks in Chicago.

Form guide: That victory over New Zealand was an outstanding accomplishment, proving that Ireland at their best are a match for anyone. Wins over the Wallabies and Springboks as well made 2016 a memorable year for the Irish, although they underachieved in the last Six Nations, winning two and drawing one of their five games.

Strengths: Ireland have the combination of talent and experience that every team needs if it is to thrive in the long term. They coped apparently effortlessly with the loss to retirement of two of their greatest ever players, Brian O’Driscoll and Paul O’Connell, and at their best are far more than the sum of their parts.

Weaknesses: Sexton would be a big loss, and even if he is passed fit to start against Scotland on Saturday there has to be a doubt about his match sharpness. There is also a sizeable question mark looming over the No 13 position, where Jared Payne will miss at least the first two fixtures because of a kidney injury.

Prediction: second

FRANCE

Key player:

LOUIS PICAMOLES

Age: 30 Position: No 8

Club: Northampton Saints Caps: 57

The only member of the squad to play his club rugby outside of France, Parisian Picamoles is a class act who provides vital determination and defiance when the chips are down. He has been in and around the squad since 2008, so also provides vital experience to a relatively untried group of players.

Coach: Guy Noves took over the national team in late 2015 after being head coach of Toulouse for more than two decades, and won his first two games in last year’s Six Nations, albeit narrowly and unconvincingly before losing the subsequent three. He now seems to have got his team playing a more effective style after some indifferent early performances.

Form guide: After finishing fifth in last season’s Six Nations - behind Scotland on points difference - France beat Samoa well in the first game of the Autumn Internationals. They then lost narrowly to both Australia and New Zealand, but recovered a fair amount of self-respect in the process after their shambolic displays in some of those Six Nations matches.

Strengths: When on form, they still play with a zest for the game unequalled anywhere. Under Noves they are also increasingly able to get the better of a dour battle, whereas at times in the past they lacked the discipline to do so.

Weaknesses: Noves has changed the personnel in the squad a lot and is now significantly short of top-level experience in some quarters. While they have a coherent style when they put their minds to it or are forced to play at their best by top-notch opposition, there is still a doubt about their ability to play that way consistently.

Prediction: fourth

WALES

Key player:

ALUN WYN JONES

Age: 31 Position: second row

Club: Ospreys Caps: 105

An occasional captain in the past, the lock forward now has the job for the tournament. That is partly in order to allow former skipper Sam Warburton to concentrate on his own game rather than leadership, but it is also tribute to Jones’s stature as one of the most relentlessly efficient perfomers in the Championship.

Coach: Rob Howley has again taken over from Warren Gatland while the New Zealander is back in charge of the Lions, who embark on a three-Test tour to his native country this summer. Howley suffered a run of six defeats during his first stint at the helm, although he got back to winning ways in time to lift the 2013 Six Nations title.

Form guide: Second in last year’s Six Nations, three points behind England, they lost their form dramatically in the autumn. A 32-8 defeat by Australia was followed by narrow wins over Argentina and Japan before the year was rounded off more encouragingly with a solid victory over South Africa.

Strengths: When their tails are up they are capable of taking on anyone, particularly at home. Besides Jones and Warburton in the pack, they can also call on battle-hardened backs such as Jamie Roberts and George North.

Weaknesses: There are still concerns about the disruption caused by Gatland’s sabbatical, and doubts about Howley’s ability to find a balance between continuing the head coach’s good work and putting his own stamp on proceedings. With seven uncapped players having been selected, there is also a question about the overall experience of the squad.

Prediction: fifth

ENGLAND

Key player:

MARO ITOJE

Age: 22 Position: second or back row

Club: Saracens Caps: 7

Man of the match in last season’s Champions Cup final as well as on his international debut, Itoje brings a dynamism to the England pack that is the perfect compliment to the older hands who can be powerful yet ponderous. Having missed the Autumn Tests because of a broken hand, he could be selected in the back row rather than at lock.

Coach: Eddie Jones quickly transformed the team from a demoralised bunch into Six Nations champions last year, and has still to taste defeat. When in charge of Japan at the last World Cup he suggested he was on the verge of retirement; instead, he has gone on to the greatest achievement of his career so far, winning 13 matches out of 13.

Form guide: Unstoppable under Jones, England are at last making best use of their considerable resources for the first time since winning the World Cup back in 2003. They have yet to play the All Blacks since the Australian took over, but have got the better of every other leading rugby nation.

Strengths: A massive playing pool has not always been properly used, but Jones has imposed order on this embarrassment of riches. His confidence and zest for the game has communicated itself to his players, who have freed themselves from the shackles of uncertainty they displayed under his predecessor Stuart Lancaster.

Weaknesses: Hard to find any in a side ranked second in the world unless you are making a direct comparison with the All Blacks. Perhaps the fact they have to visit both Cardiff and Dublin will stretch them.

Prediction: Champions (but no Grand Slam this time)

ITALY

Key player:

SERGIO PARISSE

Age: 33 Position: No 8

Club: Stade Francais Caps: 121

Italy’s captain is getting towards the end of a magnificent career and may no longer be the power he was. Nevertheless, he remains the team’s only world-class player, and his vast experience will be essential if they are to spring a surprise or two.

Coach: Conor O’Shea, the former Ireland full-back and Harlequins coach, took over from Jacques Brunel last March. He has given the Azzurri a greater sense of purpose than they had latterly under Brunel, but needs more time to overhaul a limited squad.

Form guide: Mixed - which is to say, better than usual. They lost to Argentina but beat the USA and Canada last summer, then in November were heavily defeated by New Zealand before recording a first-ever win against South Africa. The joy of that result against the Springboks evaporated a week later, however, when they were beaten by Tonga for the first time this century.

Strengths: Powerful up front, they are capable of inspired performances if the pack begins to get on top and they sense that things are going well. As invariable underdogs, they are good at sniffing out weaknesses in the opposition’s make-up, and can be ruthless on the counter-attack.

Weaknesses: They lack strength in depth, and even their established first 15 has too many journeymen to give them much of a chance unless their opponents are having an off day. Too readily lose morale when the chips are down, in part because they know as well as anyone that they lack the game-changers needed to fight back.

Prediction: Wooden Spoon