In the depths of this grim winter we’ve all needed something to keep us going, and for me it’s been rugby union’s Six Nations championship, which comes to a crunching conclusion tomorrow with three matches, including what promises to be an epic encounter between Wales and England in Cardiff.

Now, rugby is not to everybody’s taste. It’s dull, plodding and the laws are unfathomable, say the cynics, who contrast it unfavourably with the flowing, relatively straightforward game of football. And in some ways those critics are right. But they are missing the point that rugby is sport at its purest because, in reality, all sport is boring. It’s a tribal rite, not an aesthetic exercise, and no sport does tribalism better than rugby.

I had better admit at the outset that I am Welsh: born in Newport, which once prided itself on the greatness of its rugby team. (The team has taken a nosedive since I grew up there 40 years ago.) At secondary school I was taught by quite a few rugby players who played for Newport, including Colin Smart, the England prop who became famous when he downed a bottle of aftershave in a drinking contest after the 1982 France-England match and ended up in hospital.

I grew up with rugby, and loved the way the game defined Newport, who in 1963 were the only side to beat the mighty New Zealand All Blacks during a tour that included a remarkable 37 games. This muscular, dour industrial town based on iron and steel articulated itself through rugby. The football team was a national laughing stock, but the rugby players were world-beaters.

An England-Wales match is a titanic clash of cultures, histories and identities that no other sport can match. Football might claim England v Germany has the same resonance, but I don’t buy it. The emotional charge of Wales v England at Cardiff beats anything, and much of the power of Six Nations encounters is derived from the way the fans impose themselves on the occasion. This is so much more than a game.

The anthems often seem to last as long as the matches, especially in Scotland and Ireland, where they set popular anthems alongside the official ones. And the singing during games is fantastic. Whenever I hear the Irish sing The Fields of Athenry, I feel like crying, especially if they are beating the Welsh at the time, as has too frequently been the case in recent years.

Set beside all this emotion, whether the sport is a great spectacle is irrelevant. Which is fortunate because, if you treat it purely as an aesthetic form, rugby is unwatchable. The ball disappears under a heap of bodies for long periods; the scrums are endlessly set and reset as referees struggle to impose discipline; and no one really understands the rules, which makes the giving of penalties a lottery. A game lasts 80 minutes, and if 5% of that is made up of running rugby you’re doing well. The rest will be scrums, mauls, punch-ups and a small man squatting over the ball for minutes on end as he lines up a kick at goal which has resulted from some alleged offence no one can understand in the first place.

Last week’s Scotland-Wales game was reckoned to be one of the worst of all time, with neither team able to establish any fluency. It became a battle of the boot, and saw a record number of penalties in a Six Nations match. But I found it gripping. True fans don’t care about the boredom or opacity of their chosen sport. All they are seeking is validation. Of course it’s nice to win in style, as the Welsh teams of the 1970s did, but what really matters is getting one over the other nations, especially the English.

Sports like to pretend they are interesting for the casual watcher, but on the whole they aren’t. No one in their right mind would sit through a four-day golf tournament unless they were related to one of the players; cricket is best dipped into online or on the radio, or used as an excuse to sleep in a deckchair at Hove; a five-set tennis match between Federer and Nadal is a supreme athletic confrontation, yet even that starts to pall by about the third hour and I usually try to time it so I get back to the telly for the tie-breaks; as for football, it is entirely beyond the pale – all that diving, play-acting and moaning to the referee after the match.

Rugby commentator Brian Moore frequently says, “It’s not football”, when he is berating a player for indulging in soccer-style antics – complaining to the referee, say, or rolling around theatrically after being head-butted – and let’s hope that will always be the case. Rugby is the Eton wall game but with fewer points of spectatorial interest and a much less comprehensible set of rules. Therein lies its greatness. The game is so awful to watch that the crowd, the fans, the nation willing their representatives on to victory, have to create the drama.