To see an example of the value of good coaching, all you have to do is look at the Super Rugby season and the first test matches under the new All Black panel. I've been really impressed.
At Super Rugby level, we witnessed the emergence of a new Chiefs this year and saw the benefits of having coaches such as Wayne Smith, Dave Rennie and Tom Coventry really analysing the game they wanted to play, their players and their opponents.
They thrived with their week-in, week-out work. They really got hold of their team and did the business.
As for the All Black coaching panel, they have come out of it with flying colours so far. There will be some tough times to come - there always are in coaching - but the signs are good.
They did well against Ireland and learned the lessons that were there to be learned. There's no resting on any Rugby World Cup laurels; it's not even mentioned and they are looking ahead all the time.
"We want to get better" is the theme I hear emerging all the time.
Head coach Steve Hansen is doing well and, even if we don't see much of them in the limelight, Ian Foster, Aussie McLean and Grant Fox are clearly working well as a team.
For me, there's been two main achievements so far - the accuracy of this All Black team and the coaching that is going into them. There was some rust last weekend but it seems to me that all the All Blacks need is some fine tuning and they will be dangerous. What stands out for me is how accurate individually the All Blacks are in most things they do.
Taken over the five tests so far this season, the number of mistakes they make collectively could be counted on one hand.
In doing that, they build unbelievable pressure on their opponents. The only thing that kept the Aussies in the game last week was referee Alain Rolland. The game got away from him a bit, I felt, and he was a lot happier making it a stop-start affair as a result.
As for coaching making a difference, the players I speak to say that the experienced guys and the guys who need coaching are both benefitting from the work of this All Black panel. In past years, players were maybe able to cope better at top level and didn't need quite so much coaching input.
But the game has changed - a lot - and there are coaches who are really up to speed now and who really make a difference. I think that is what we are seeing with the early work of this new panel.
For example, in last week's test, look at the two tries they scored against the Australians from set pieces. They'd really done their homework there. They'd all sat down and worked it out - they knew how the Australians would react defensively and, for Israel Dagg's try, they knew that Dan Carter going left and Sonny Bill Williams running decoy would stretch the Wallaby defence.
Here in the UK, you can see the same thing happening when good coaches come into a club - such as Harlequins, where Conor O'Shea has really lifted them. It wasn't that the previous coaches were bad, it's just that new structures have been built, there's a new level of communication and the players are buying into it all.
That's what I can see is being set in place at the Blues too. John Kirwan is getting all his ducks in a row and it's a massive bonus for him to have Graham Henry there. With Mick Byrne also on board, you can see a strong coaching team starting to form and, as long as JK is in control, what a backstop he has in Henry as a mentor.
The signs are good for the Blues too - and they'll need the players to buy into what is happening - but it looks as though this will be another strong coaching team that can make a difference and which wants to "do better".