“It’s like going on a date with somebody else.”

Jim ‘Bones’ Mackay’s analysis of the effect a new caddie can have on a tour player was a rather neat summation.

One swallow doesn’t make a summer, but Jason Day certainly looked none the worse for his split with long-term bagman Colin Swatton when posting an opening 64 in the first round of the BMW Championship.

Mackay, of course, has insight few others can offer into the complex player-caddie relationship.

But if his split with Phil Mickelson, after a quarter of a century, sent tremors through the golf world then Day’s parting from Swatton was seismic.

Taking him as a kid who drank too much and got into fights, following the death of his dad when he was 12, this new father figure coached and mentored him into a major champion.

Swatton will remain in the camp – and Day hasn’t ruled out going back to him at some point in the future.

But, for the moment at least, he is the latest in a growing list of casualties in the schism between leading PGA Tour players and caddies.

With Mickelson ditching Mackay for brother Tim, and Rory McIlroy parting company with JP Fitzgerald for close friend Harry Diamond, a trend seems to be emerging.

Jason Day split

Professional golfers can be like lemmings leaping off a cliff. One does something, another thinks ‘oh, that looks good’ and, before you know it, half the tour are following suit.

Want an example? Just think about the meteoric rise of the TaylorMade Spider putter employed so successfully by Day.

Dustin Johnson was among the first of the game’s superstars to ditch the ‘professional’ caddie and look a bit closer to home for inspiration.

His brother Austin did little to start with other than handing him a club, cleaning his ball, raking a bunker and giving him a bit of brotherly love in a tough situation.

That relationship has clearly developed over the years as DJ has risen to the top of the sport.

It’s difficult to imagine, though, despite Diamond’s pedigree as an excellent amateur golfer, that he and Rory are currently conversing – Spieth-Greller style – about the intricacies of this or that particular wind.

So what’s all this really about?

It’s like having a girlfriend for 10 years and then being cut loose (ditched). You might turn to your ‘best girl friend’ for a shoulder to cry on, things feel different, they feel nicer.

You’re like a new person, you like the new you. Why not make this permanent?

All of which could have interesting ramifications for the future role of the looper.

Modern golf projects player/caddie combinations as inseparable teams. The player hits the shots, of course, and is ultimately responsible for the outcome.

But 21st century caddies are also portrayed as selfless heroes.

When things are going well, they are written about as being up as the sun rises – pacing the course to get the day’s pin positions, picking out that unusual yardage that might just occur every one in 100 rounds, and generally leaving absolutely no stone unturned in the pursuit of victory.

Players routinely reinforce this in interviews with the use of the third person. It’s not ‘I’, it’s ‘we’.

Jason Day split

‘We hit a good number on 13’. ‘We ground it out on the back nine’.

We. A team. A partnership.

Is there an argument that some of the game’s best players are now starting to get away from that?

“I’ve got a buddy on the bag,” said Day explaining his decision to swat Swatton. “I might have another buddy on the bag at the Presidents Cup.”

Whether this all bears significant fruit remains to be seen. It all seems very short term to me.

Unlike Johnson, neither McIlroy nor Mickelson, until last week at least, have been pulling up any trees since their respective divorces.

But if that changes anytime soon, then perhaps we’ll be hailing the rise of the ‘pal’ rather than the professional caddie.