The secret deals in poaching assistant coaches in the AFL Former Melbourne assistant coach Neil Craig, right, has joined Essendon to help stand-in coach Mark Thompson, who takes over for James Hird in 2014. IT happens in private phone calls and meetings at neutral venues. Deals are kept quiet until announcements are made and clubs are paranoid about secrets that are told. It's the merry-go-round of assistant coaches in the AFL, where half of the time assistants are moved on when a new coach comes in or seek a move to further their own careers. This year, it has been raft of interchanges between clubs, because that is the nature of this other trading period. Prominent assistants who have made a move include Collingwood Team of the Century member Gavin Brown, who crossed from Carlton to North Melbourne, and respected senior assistant Phil Walsh, who returned to Alberton after a stint at West Coast. There are few things that worry clubs more than intellectual property, IP, walking out the door, because there are still incredibly valuable secrets in football. In particular, clubs value their game plan, training methodology and list management strategy. Astute judges can narrow down how a team wants to play - its ball movements, key players, exit strategies from stoppages, ruck combinations, kick-outs and kick out defence. But teams rarely executes its game to perfection, there are always nuances that are lost, pattern that did not unfold according to plan. Knowing exactly what each player is instructed to do and what the team rules are in certain situations would be invaluable for an opposition club. Likewise, clubs have training sessions for the world to see, and even the closed ones are impossible to safeguard. But much is done behind closed doors at football clubs. The programs designed by clubs have different emphasis on running versus weights, meetings versus recovery, shifts in training load and what order in which to do things. The secret is not so much what the players do - those in the know could probably copy some of the best programs - but how they do it. But the big one is list management. Because of the amount of movement among assistant coaches, they are often kept at arm's length from the exact details of these documents. They have an input - they are often asked how they see the short-term and long-term future of players several times a year - but the full details of list management IP are generally kept to as few people as possible. The list manager, the senior coach, the football manager and maybe the senior assistant. These documents include what each player is paid each year - important as the puzzle of keeping under the salary cap is put together - and what the club's plans are for the player. One current coach said you could spot leaked IP every year; when a player from a development academy is suddenly signed on a three-year deal or when a mid-range player is courted heavily by a club who has an assistant who previously worked at the players' club. Measures other than keeping the knowledge base to a limited amount of people are in place at most clubs. At this time of year, computer servers are shut down and there is some information that, year-round, can only be accessed on computers at the club. In 2007, part of Damien Hardwick's challenge when he applied to the vacant job at Essendon was that Hawthorn, his employer, did not allow him to take his laptop to present the information he had compiled. There was a risk Hawthorn IP on the computer would leak out. For all of the safeguards, clubs still try to find out what the other mobs are up to. One coach said the interview stage of the hiring process was an ideal time to find out. "Even if you're pretty sure who you're after, it always pays to interview a few candidates from the best clubs," he said. You always find out something from the process, even if you don't end up hiring the person. The other thing about most IP is that it exists in the coaches' memories. It is part of why assistants at the leading clubs have their stocks soar. The moves are either club driven, or initiated by the assistant. As a rule, assistants are on shaky ground when a new senior coach arrives. Depending on the club's finances, the new senior coach may either be in a position to clear the decks and bring in his own men - like Malcolm Blight did at St Kilda - or is forced to have the assistants at the club at least serve out their current contracts. Clubs on AFL assistance and those with small profit margins are most likely to opt for the latter, with the board considering paying out a handful of assistants a frivolous waste of money. There are also times when clubs actively search for a proven assistant. Port Adelaide knew the strategic influence that could be gained from Walsh and was in a position to recruit him when assistant Shaun Rehn's contract was up. But the assistants also seek moves in a calculated manner, taking advantage of the transient nature of the industry. Then there's the assistant who has missed out on the senior job at his club, like Mark Bickley at Adelaide. Bickley is an exception in that he remains at the club under Brenton Sanderson, who beat him to the position vacated by Neil Craig, because more often a not it could have led to an awkward relationship. What settled it was that Sanderson was strong in endorsing Bickley to stay with the Crows. For an assistant to be considered, he has to have one of two assets: a reputation within the industry, or well-credentialed figures who can vouch for him. Some former players have clubs clamouring for their services before they've even put their hands up. Cameron Ling, the former Geelong premiership captain, remains one of the game's most sought-after assistants but has so far resisted. His media work has only helped his prospects; he deals with the clubs on a regular basis, has come across as confident and level-headed and had a chance to express the values he stands for. Others in Ling's category include former Sydney captain Brett Kirk, who was widely regarded as the spiritual leader of the Bloods. He is now Fremantle's midfield coach, having also spent time as a commentator. But other, lower-profile players, make it. Generally it is because of their close working relationship with one of their coaches, who has seen first-hand what the player is like when it comes to leadership and integrity. His greatest challenge will be to impress other clubs if he wants to one day advance to a senior position. Then there are those who take the long way, like Nathan Bassett and Josh Francou, who built up their coaching resumes in the SANFL.