Robertson was initially intending to spend the 2012 season in the less stressful role of sideline observer but when Greytown found themselves without a coach and he was asked to fill the vacancy, his loyalty to his old club saw him step into the breach.
By his own admission, Robertson didn't regard Greytown as a serious contender for the Tui Cup title until the start of the qualifying games for that competition.
A slow start had seen them well down the table in the Kapene Cup first round series but he was encouraged enough by the steady improvement shown by the side through the latter stages of that campaign to think better things were close at hand.
"Honestly, I was surprised how quickly they developed once we got them on board and showed them the type of game which would be most suited to their talents."
The Robertson coaching method is based around identifying which players can best fit what he regards as the six most influential positions on a rugby field: hooker, openside flanker, No 8, halfback, first-five and fullback.
"Get those right, and you can build a team around them," he said.
Robertson also likes to ask each player to give him in order the three positions they would prefer to play, with the proviso that once they had been given the chance to show what they could do in them, it was up to the coach to decide where they ended up.
"You have to have trust in them and they have to have trust in you ... you all have to be working off the same page."
Another leaf out of the Robertson coaching book comes from a conversation he had with the great Sir Brian Lochore.
"BJ told me to never forget that you play rugby with a ball and therefore the more you used a ball in training, the more sense it made. I've never forgotten that."
Always one to speak his mind, Robertson strongly believes too many coaches these days have become stereotyped in their approach, something he reckons is the result of higher level coaching courses constantly stressing the same things.
"How often do you see forwards bashing the ball up league-style time and time again? You sometimes wonder whether variation is even part of the game any more," he said. "Coaches should be prepared to try something different, to not have their players acting like robots."
Almost without exception, Robertson watches the first half of games standing behind the goalposts at one end of the paddock, a position from which he can best see the alignment of both sets of backs.
"You often notice something which can be addressed at halftime," he said.
Robertson is also a great believer in noting the strengths and deficiencies of opposing teams with an eye to being better prepared for their next meeting. He also doesn't hold with club sides starting their training sessions as early as November.
"What you have to remember is that the real guts of our club season starts when the Tui Cup kicks off and that's when you need the players to be really hitting their straps. There's no value in having them going into that competition feeling flat and tired."
Whether Robertson's success with Greytown in 2012 will be his last hurrah as a premier division coach remains to be seen.
Right now, he has no intentions of a repeat but such is his affinity with the game, he admits any request from a club seeking help from him in a technical sense would be difficult to turn down.
"Maybe I still have a bit to offer ... we'll wait and see what happens."
