Fantasy Football Definition of "Depth Chart"
Looking at an accurate NFL "depth chart" is important just before a fantasy football draft, because NFL depth charts remain fluid throughout the preseason. In fact, teams are purposefully deceptive about their depth charts sometimes, hoping to spring a surprise on their Week 1 NFL opponent. NFL.com no longer posts preseason team depth charts until after final cuts are made, because they can't stand by the accuracy of these depth charts. So having the right information on NFL starters and backups is a big advantage in a fantasy football draft.
Depth Chart and Fantasy Drafts
The later a fantasy football draft takes place, the more accurate your depth chart information is going to be. I would recommend having your fantasy drafts after Week 3 of the NFL Preseason at the very least, because that's considered the dress rehearsal for the NFL regular season. Though the starting lineups and who plays in the first half of these preseason games are not the end-all on team depth charts, they do provide the best in-game clues as to who the coaches like and trust the most on their teams. Some veterans (Ladainian Tomlinson, Frank Gore) won't play in these games, either, but those are no-brainer starters and therefore you don't need to look at their play-by-play to know these guys are the starters. The same can't be said for a lot of NFL running back situations and wide receiving corps.
Depth Chart Information
Even then, don't let the preseason be your only guide. Go to fantasy football sites that you trust and look at their depth chart information. Some of these will be updated daily, while others aren't updated for months. Look at multiple depth charts for the teams in question, seeing if there's an emerging pattern or an inconsistency that needs to be explored. Look at local media training camp reports, NFL news and preseason recaps to see if a team's beat reporters have an inside scoop on who the true starter is. Go on NFL message boards and forums and see what the local fans are seeing.
Using all these methods can still be inadequate. Divining what a team's true depth chart can still be next to impossible, if the coaches are determined to hide their team's secrets. Prior to the NFL Draft, teams are deceptive and evasive to the local and national sports media about their draft strategy, so it's no surprise they might be deceptive when talking to the same people about what the opening week lineup is going to look like. So you can use every method of your disposal to determine a team's depth chart, and still end up drafting the team's backup instead of their starter. My advice would be to avoid (in the first 6-7 rounds) any situations where there's a question, because you don't want to whiff on a high-round pick. The problem is, even seemingly answered depth chart questions can sometimes change in the week leading up to the NFL season. Let me give a couple of examples from this year.
Tampa Bay Buccaneers Depth Chart
The Tampa Bay Buccaneers signed Derrick Ward to a big free agent contract in the offseason, presumably to be their starting running back. That's what happens to guys signed to big contracts: they become the starters. Everyone assumed the Bucs depth chart would be Derrick Ward as the starter, Earnest Graham as the primary backup and Cadillac Williams as the definite third option. Any fantasy football draft that happened two weeks before the season or longer held to this logic.
Then, in the week leading up to the NFL season, media reports started to circulate that Carnell "Cadillac" Williams would be the Bucs starter, if he were healthy. This sounded like gamesmanship to fool opposing defensive coordinators at first, but then fantasy footballers were reminded that Troy Aikman had said the same weeks before in a Fox NFL Broadcast. Suddenly, more and more reports started coming in about Cadillac Williams as the starter, people started picking up Cadillac up off the waiver wire, and any Derrick Ward owners who weren't paying close attention found themselves having the rug pulled out from under them days before the season. Sure enough, Week 1, Cadillac Williams got the start and now was the Buccaneers starting RB.
Oakland Raiders Depth Chart
One should always be wary when drafting Oakland Raiders, because crazy old Al Davis is the man ultimately making the decisions in Oakland. But the idea that Darren McFadden was the Raiders' go-to guy at running back seemed about as set-in-stone as anything can be at the Raiders camp. Darren McFadden had been the 4th overall pick the year before and Al Davis loves speed. Darren McFadden had looked pretty good in one or two of the Raiders preseason games (less good in one or two others). Just about everyone assumed Darren McFadden would get his chance to prove he's a superstar in Oakland, if nothing else to keep Al Davis from looking the fool again.
Jump to the week before the 2009 NFL Season started. Tom Cable mentions casually he would decide by the end of the week who the Raiders starting running back would be: Darren McFadden, Michael Bush or Justin Fargas. This came out of the blue. Eventually, Tom Cable named McFadden the starter and all McFadden fans breathed a sigh of relief, assuming this was once again gamesmanship on the part of the Raiders. But when the Raiders took the field against the San Diego Chargers in Week 1, Darren McFadden and Michael Bush were splitting the carries at something like a 60/40 ratio. Panic and disgust sat in with the Darren McFadden fantasy owners around the country. Al Davis had struck again.
So fantasy football depth charts are sometimes like reading tea leaves: it's pretty much anybody's guess. Get the best depth chart information you can, draft accordingly and then cross your fingers.