If the twirl of the club after executing a shot is the definitive tell-tale sign of Rory McIlroy’s brilliance, it is something unseen that really makes him tick. That inner strength of mind, a total belief in himself, is something that money can’t buy; and the 27-year-old Northern Irishman’s Tour Championship victory and annexation of the FedEx Cup title with a combined $11.5 million bonus payday is testament to McIlroy’s conviction.

In terms of timing, McIlroy’s all-conquering win in the Tour Championship was perfect for Europe’s Ryder Cup team ahead of the match at Hazeltine this week. Yet, this win was for himself and his team and the decision to switch putters - made in the days and weeks after missing the cut at the US PGA at Baltusrol - has proven to be the wisest of moves.

McIlroy's personal CV is very nearly complete, with only the Masters left. By winning the Tour Championship - and, in typical McIlroy fashion, with drama and flair - the world number three turned a decent season into a great season. But that decision to switch to a Scotty Cameron prototype mallet could yet prove to be a career-defining move that could also contribute to ticking that final box at Augusta National some time.

Up to the PGA Championship, where he led the field tee-to-green but was towards the bottom in putting statistics and missed the cut, McIlroy had used his Nike Method Origin B2-01 putter. It was a blade-style putter head he had always favoured. By putting the Scotty Cameron Concept M1 prototype mallet into his bag, and starting to work with putting guru Phil Kenyon, McIlroy took it on himself to fix the one part of his game that was prone to let him down.

As he observed, "Leaving Baltusrol, obviously I was very disappointed and I needed to think about a few things. I needed to assess where my game was and address a few issues." And, when it mattered at East Lake, his putting stayed strong and did its job.

McIlroy - who has used the new mallet putter since the Barclays, the first of the FedEx Cup play-offs and a month of golf in which he has won both the Deutsche Bank and the Tour Championshp - explained that changing to a mallet helped to keep the clubface square at impact. "It doesn't encourage that face to close that much, which is the bad putt I was getting. It encourages the face to stay a little more square through impact."

It all sounds rather simple but the fact is that such a change took courage in its own way to make, and the dividends are now clearly evidenced by a bulging bank account on the back of his wins and manoeuvring his way to within 2.3 points of world number one Jason Day in the rankings.

This week McIlroy moves back into team mode for the Ryder Cup and the photo posted on the European Ryder Cup twitter account of those players and back-room members gathered in London celebrating his play-off win ahead of the flight to Minneapolis was proof itself of how it could yet galvanise Clarke's team. An in-form McIlroy is a sight to behold and the expectation is that he will play in all five sessions in an on-course leader role.

McIlroy's play-off victory, firstly seeing off Kevin Chappell who fell away at the first hole of sudden death and then beating Ryan Moore on the fourth play-off hole, was stunning and dramatic. The defining moment of course was in holing-out for an eagle two on the 16th in regulation and it was somehow fitting that it should all end on that same green.

Back in 2012, McIlroy had won twice in the FedEx Cup play-offs - the Deutsche Bank and the BMW - only to be overtaken by Brandt Snedeker for the ultimate megabucks bonus prize. This time, McIlroy entered the play-offs ranked 36th and manoeuvred his way into the winning position. "To shoot 66, 64 on the weekend to win the Tour Championship and ultimately win the FedEx Cup, that ranks up there with just some of my best performances on the golf course regardless of the tournament.....it means an awful lot. I've made no secret that it's one of the last things I feel like I had left on my golfing CV, and I made it a big goal of mine, especially after the summer had gone, to win it."