Of current Championship clubs, what do Barnsley, Nottingham Forest, Scunthorpe and Watford have in common?

The answer is that none of them has had a player sent off yet this season, although Barnsley’s official tally of 252 fouls committed has been exceeded by only three teams.

The same Football League statistics show that Leeds top the Championship table when it comes to fouls with 268, on which I make no further comment, while the clubs with most red cards are Burnley, Crystal Palace and Sheffield United, with four each.

Promotion-chasing Leeds and bottom-of-the-table Preston have the most bookings with 42 each, an average of two per match.

Norwich City’s own disciplinary record has taken a bit of a knock in recent weeks with three red cards in the past seven matches, though one of them – skipper Grant Holt’s ridiculous dismissal at Reading – has since been rescinded.

The Canaries managed to get through the first three months of the season without seeing red until Andrew Crofts’ two yellow cards in the home game against Burnley. Then came Holt’s early exit at the Madejski Stadium a week later and, last Saturday, defender Leon Barnett’s injury-time departure for a second yellow card against Portsmouth.

Barnett’s regrettable reaction, throwing the ball at referee Simon Hooper, means the repercussions of his red card may well be felt beyond tomorrow’s one-match ban at Coventry – he has a personal hearing before the FA on Wednesday – and one can only hope his swift apology to the match official will help his cause.

While I would not condone throwing the ball, or anything else, at referees – though those green cushions in the old wooden Main Stand used to make very effective missiles – two points can perhaps be made in Barnett’s defence.

The first is that he may still have been feeling a sense of injustice over his initial yellow card, a harsh decision for a challenge on Dave Kitson, and the second is that it is hard to imagine anyone less likely to deliberately hurt an opponent or an official than this mild-mannered young footballer. It was, as he insisted, “out of character”.

Nevertheless, losing key players through suspension has already cost City this season and they should do all they can to eliminate self-inflicted damage.

The one match that defender Elliott Ward missed through a ban ended in a 2-1 home defeat by Crystal Palace and it could certainly be argued that top scorer Holt’s absence was a factor in last week’s 2-0 home defeat by Portsmouth.

With Crofts and Simon Lappin currently on four yellow cards, and Barnett resuming on four yellows when he has served his ban, there is a risk of losing key individuals over the Christmas and New Year period when City play four times in nine days.

There have been some questionable bookings, yes, but also some needless cautions for time-wasting and dissent.

Generally, though, whether by chance or by design, the players’ discipline appears to have tightened up a degree during Paul Lambert’s time as manager.

The four seasons of Championship football immediately following relegation from the Premiership brought the Canaries 17 red cards and 289 bookings. The 2007-08 season alone brought 77 yellow and seven red cards and City twice finished matches with nine men.

Though there were five dismissals last season, at least two of them – Fraser Forster at Gillingham and Darel Russell against Southampton – were debatable and, apart from Holt being suspended three times, City coped well during the few suspensions that came their way.

It is difficult to pin down statistics that show a definite correlation between success and good behaviour on the field but City’s own fairly recent past includes a good example of how the two can go hand in hand.

When Mike Walker’s Canaries finished in their highest league position of third in the FA Premier League in 1992-93, they also won the Fair Play Award.

When Walker returned as manager four years later, he inevitably had a less talented squad at his disposal in a lower division and they finished 13th in Division One, but with 10 red cards in his first season back, on-field discipline also suffered.

Is better discipline a symptom or a cause of success? It could be argued that teams are better behaved because they are winning most of the time and are therefore in a more positive frame of mind, but one might also argue that winning comes partly from being more disciplined in the first place – and therefore losing fewer players to red cards and suspension. City will certainly feel the benefit if they can keep the Christmas cards to a minimum.