No sooner do the AFL players stop swapping clubs, then the coaches start getting into it.

Tuesday was a remarkable day on that front, with the coaching musical chairs in full swing, with some surprising names heading to some even more surprising destinations.

The day started with Collingwood announcing that Matthew Lappin and Craig McRae were heading to the Westpac Centre. No major surprises there; Lappin was squeezed out by the arrival at Carlton of Alan Richardson and Gavin Brown, while McRae's return to Victoria has been mooted for weeks.

Then it got interesting. Geelong announced the departure of longtime assistant Brendan McCartney to Essendon. In their statement, the Cats accepted with "reluctance" that McCartney, named the assistant coach of the year by the AFL Coaches Association wouldn't continue to head up the club's development program.

The Bombers have earmarked McCartney as 'senior match day assistant' to new coach James Hird and his arrival at Windy Hill is surely further evidence that Mark Thompson - reportedly very close to McCartney - will follow some time in the new year.

Then came Todd Viney's departure from Adelaide after just two seasons to become Melbourne's general manager of player development, a new position created by the Demons, although as the cynics might suggest, one created purely to snuff out any hopes that Viney's talented son Jack might decide to stay home and play with the Crows rather than join the Demons as a father-son selection.

Viney was in a real hurry to get back to Adelaide two years ago for some sort of family reason. The Crows grabbed him quickly and were delighted to take some IP from Hawthorn, the recently crowned premiership team, of which Viney was a key architect.

Both Viney and McCartney were under contract and it used to be that coaches only broke their contracts for genuine promotions elsewhere. But in this, the year of the coaching carousel, that seemed to have changed.

So many AFL assistant coaches will sport new colours next season. Among the more notable: Robert Harvey (Carlton to St Kilda), Leon Cameron (Western Bulldogs to Hawthorn), Leigh Tudor (St Kilda to Sydney), Sean Wellman (Melbourne to Essendon), Gavin Brown (Collingwood to Carlton), Alan Richardson (Essendon to Carlton), David Teague (Carlton to West Coast), Paul Hudson (Collingwood to St Kilda) and Peter Berbakov (Sydney to St Kilda).

Sprinkled among these (Wellman and Harvey) are some favourite sons returning home. And seeing Collingwood lifer Brown in the navy blue and white will take some getting used to.

But it's mainly about a thirst for knowledge and the search for better opportunities that has caused such a huge turnover in the AFL coaching backrooms.

As clubs make more more money each season in a sport ruled by a salary cap, bigger and better-resourced coaching departments is where clubs hope to gain their competitive edge.

Between the line coaches and the development coaches, Like many clubs, Hawthorn will have a coaching department large enough to be its own cricket team. But it won't amount to anything if Jarryd Roughead still hasn't learned how to kick straight.