After months of speculation and two weeks of intense negotiation, the 2018 AFL Trade and Free Agency period came to a climactic conclusion last night as the final deals hit the desks of AFL HQ.

Well, we figure most of the action was happening behind closed doors.

The trade and free agency period saw 41 players find a new home and 39 different exchanges, an equal record and up by nine on the last trade period.

The draft is easily the most important way, by volume, of acquiring talent, but trading helps determine where the picks will fall. Trading can also fill the gaps with targeted additions.

At least in theory.

Although the trade period has just closed, our early analysis suggests some probable winners and losers.

We developed a series of analytical tools to evaluate the history of good and bad list management for the book, Footballistics, published by ABC Books this year.

The key was a method of player evaluation we called Player Approximate Value (or PAV, for short).

Brownlow Medallist Tom Mitchell led the league in PAVs this season. ( AAP: Julian Smith )

PAV gives each player a season rating in three different areas (attack, defence and midfield) based on the ability of their team, and their contribution to their side's effort.

More than 20 PAVs is an outstanding season. The league average is about eight PAVs (about what Luke Dahlhaus produced in 2018), with the least productive player in the league close to zero (the injured Tim Broomhead).

Tom Mitchell led the league with 26 PAVs this year, with Patrick Dangerfield, Brodie Grundy, Dustin Martin and Max Gawn filling out the top five.

Utilising the PAV rating system, we have also developed a method of future career prediction called PAPLEY that models a player's future career value based on more than 16,000 player seasons over the past 30 years.

Past performance and historical comparisons are used to project the most likely future PAV for each player in the league.

Finally, we have modelled the expected output of each draft selection based on the past performance of draft picks. This means that both picks and players are measured in the same future expected PAV terms, so everything that gets swapped during trade week can be directly compared.

Still with us? Good.

The big winners

Best single trade win — Port Adelaide

Chad Wingard has left the Power to join Hawthorn, but Port Adelaide may have got the better of the deal. ( AAP: Joe Castro )

Port Adelaide obtained Ryan Burton, pick 15, pick 35 and Hawthorn's 2019 round four pick in exchange for Chad Wingard and a future third-round pick.

All trades have both immediate and long-term consequences, and few trades better display the difference between the two than this one.

Wingard should be the most valuable element from this deal in the AFL in 2019: possibly an All Australian contender.

However, Burton is already a good player with a long career ahead of him. He was second in the Rising Star two years ago, and should continue to improve at Alberton.

In the long run, it is likely that the combination of an excellent young player, a first-round pick and a second-round pick will produce more value than four to five years of a borderline All-Australian.

Best additions for 2019 — North Melbourne

North Melbourne defied rebuilding mode in 2018 and nobody was more aggressive in getting ready-made, potential best 22 players for 2019.

Jared Polec could help make the difference to the North Melbourne midfield. ( AAP: Julian Smith )

The Kangaroos shed a talented back-up ruckman (Braydon Preuss) and a promising young defender/midfielder (Ryan Clarke) for four players in the prime of their careers in Jared Polec, Dom Tyson, Jasper Pittard and Aaron Hall.

Either Pittard or Hall should fill Clarke's 2018 role, while Tyson and Polec should upgrade a midfield unit that sometimes lacked depth and variety.

However, as Essendon and Port Adelaide showed in 2018, sometimes recruiting players isn't enough. Clubs also need to figure out how to integrate them into existing tactical setups.

Most long term value added — Fremantle

Fremantle balanced their trade period nicely between recruiting for their most pressing need in a powerful key position forward (Jesse Hogan), and building for the future.

The Dockers capitalised on Port's desperation to move up the draft order, getting two decent second-round picks for a small slide in the first round, the result of which (pick 11) was later included in the Rory Lobb deal.

While they ended up losing reigning club champion Lachie Neale, the midfield is potentially the most overstocked part of the Fremantle list. Their slide down the draft order should be relatively inconsequential in the long run.

The big losers

Most long term value lost — Carlton

Carlton finished bottom of the ladder last season, and have lost a lot of their long-term value. ( AAP: Julian Smith )

Carlton have lost by far the most long-term value, shedding most draft picks and giving up their two state league concessions.

History suggests mature-age draftees tend to contribute at late second-round pick levels over their career: exactly the types of players Carlton need to fill out their best 22.

The Blues will back Mitch McGovern and Will Setterfield to outperform our projections and make up some of this ground, but it is far from certain they will.

Most ground lost in 2019 — GWS

The Giants, perhaps unsurprisingly, have lost more ground on our measures than any other club next year.

Rory Lobb, Dylan Shiel and Tom Scully (ankle permitting) were all going to be valued best 22 players.

The Giants' compensation comes in the form of draft picks, especially 2019 selections.

Picks nine and 11 could provide some immediate on-field value.

The Giants will need better luck with injury, and more midfield value from Tim Taranto, Jacob Hopper, Lachie Whitfield, Zac Williams, and maybe Harry Perryman, Nick Shipley and Aiden Bonar, to remain in premiership contention next year.

Let's check back in with the trade room for the final summary.

The exasperated man on the left brings up a good point. While these projections will likely be somewhat accurate, we won't know the final outcomes of the trades for at least 12 months, or maybe even in the next decade.