Players are rated on a range of skills, and those with an overall score of 75% or above will be watched by chief scout, Steve Head.
Character checks will be made, Head will then watch the player himself and make recommendations to Russell Slade, who has the final say.
Duane Holmes – now at table-topping Scunthorpe – is an example of a player who fell at the final hurdle.
The midfielder’s contract at Huddersfield expired in the summer, and he was expected to join the Addicks, but Slade vetoed the move.
Charlton have already compiled a provisional list of targets for the January window, and this will be monitored and regularly updated if injuries change the manager’s priorities.
Lowly Chesterfield visit The Valley on Saturday and Slade will be confident of taking the three points.
Despite having striker Ched Evans in their ranks, the Spireites have generally found goals hard to come by this season. They have yet to win on their travels, drawing two and losing five of their seven away games in the league.
They have drawn one and lost six of their last seven games in all competitions.
Slade will have Kevin Foley and Patrick Bauer available, and he will have to decide whether to include Nicky Ajose in his starting line-up.
The Addicks may look something like this:
Rudd; Solly, Bauer, Pearce, Fox; Holmes, Crofts, Ulvestad, Lookman; Magennis, Ajose.
Subs: Phillips, Konsa, Chicksen, Foley, Jackson, Novak, Hanlan.
The referee will be John Busby of Oxfordshire.
This is a game Charlton will be confident of winning, and anything less than three points would be disappointing.