Skill levels at the highest echelons of 15-a-side rugby union are "miles behind" other professional sports, Ben Ryan has claimed.
Former England Sevens coach Ryan, who led Fiji to the Olympic men's rugby sevens title in Rio last summer and is currently working as a Welsh Rugby Union consultant, is one of rugby union's most respected figures.
And he believes that skill levels are lower than they should be.
Writing in a blog published on his website www.benryan.co.uk, Ryan said: "When you compare rugby XVs skills at the highest levels to other professional sports - particularly in the USA - then we are miles behind.
"Take the NBA (National Basketball Association). Every attempted shot is technically on the money. Every single one.
"Watch them play or train, and you will see the same exacting technique that has been practised ad nauseam.
"You need to be technically brilliant in attack and defence, or you get found out quickly. Skill reproduction is seen as a huge priority. Why? Because the teams at the highest level win the most. Skill = success.
"We are still a very young professional sport in comparative terms, and I would say that our pass, catch and tackling skills are no more advanced than those playing the game 30-40 years ago.
"If the skill sets aren't encouraged to improve across the board, then the game will become less accurate and based more on size and strength than skills and technique. That would only lead to a dilution of the sport."
Ryan highlighted the skill of players' passing ability as a particular issue.
"Pass technique varies with every pass, and rarely do their hands end up pointing towards their intended target,' the 45-year-old said.
"Hands are rarely up ready to receive a pass unless they are actually acting as a decoy player. A movement sideways, rather than forward, is often the case.
"Tackle technique is more about the hit than the process. Again, players' arms at their sides in the defensive line, not up and ready to tackle, their feet too far away from the tackle and their head facing down towards the grass, unable to see what's happening.
"It's often summed up by clips shown on websites or TV of a team preparing.
"Last week, there was one of England and all their players with their arms down in the defensive line. That was prefixed by a clip of an attack with players taking steps sideways, hands late to come up to receive the ball and passes too low."