In his recent book The Black Swan, author Nassim Taleb takes his title from a David Hume quote. "No amount of observations of white swans can allow the inference that all swans are white, but the observation of a single black swan is sufficient to refute that conclusion." It's a good lesson to think about with fantasy football and injuries. Just as you know the schemes, the strategies, the dollar values, and that one thing you just know no one else does, you'd better know risk.

Everyone knows that LaDainian Tomlinson is the top pick in nearly every league, but most of us were just as sure last year that the next two should be Shaun Alexander and Larry Johnson. Injuries are a risk and a certainty, something that we have to account for, but can never really be sure about. That Alexander spent much of 2006 fighting injuries while Johnson spent much of 2006 making touchdowns doesn't make the decision to pick one or the other a coin flip. In fact, you could say that the opposite of what many would expect is true -- Johnson, not Alexander, is the more likely to be injured in 2007.

Over the course of this season, I'll be along to help you understand how injuries are affecting teams on the field and on your fantasy team. Luckily, injuries affect both pretty much the same way. The Colts are hosed if Peyton Manning goes down; so is your fantasy team. What you might not expect is that while Walter Jones won't show up on anyone's draft list, his injury last year affected Alexander, Matt Hasselbeck and Deion Branch -- who I assume are on a lot of draft lists. Looking at the game through the lens of player injuries and team health is a new way of looking at football, but it just might be your edge. With camps opening next week, let's get to it:

• 370. It's a number you're going to hear a lot this season when we discuss Larry Johnson. It's the magic number for running backs, or rather it's the reverse of magic numbers, the "cursed 370", because once a back passes that number of carries, he's in for a quick, precipitous decline. Research done by Aaron Schatz and Doug Farrar of Pro Football Prospectus shows that almost no one comes back from a 370-carry season with anything approaching their previous level of effectiveness.

The aggregate for an elite group that include John Riggins, Jerome Bettis, Earl Campbell and Terrell Davis was down over 30 percent the year following the heavy workload. Unless you're convinced that Johnson is the second coming of Eric Dickerson (the only player for whom the 370 bell didn't toll), then you're signing up for 30 percent less of Johnson at the same high pick or auction price.

Worse, his line has grown even thinner, and with the likelihood that Brodie Croyle opens the season under center, defenses are likely to stack the box, gambling that Croyle can't beat them and that Herm Edwards will intractably run, as he did in the Chiefs' playoff loss. Even a lengthy holdout doesn't figure to give Johnson enough rest to overcome the cursed 370, although Priest Holmes' reporting to training camp could put pressure on Johnson to report. Still, I fear we'll be talking about Johnson a lot in this column this season.

• As if the Falcons didn't have enough worries, they'll now be without Warrick Dunn through at least all of training camp. Dunn had what the Falcons called "minor back surgery." Of course, any back surgery is minor when it's not your back, but this procedure, likely a microdiscectomy, is as minor as back surgeries go. It's still back surgery, still requires at least six weeks to recover from, and worse, I can't find any comparable players who have had this type of injury or surgery and returned. It's more the fullback, blasting in bent down, that have this style injury. Dunn didn't do this on the field, so again, it's not the same thing. He's eminently risky at this stage and until we see him run and cut, I'd stay away. Jerious Norwood is likely to be the big beneficiary.

• Last year at this time, we all wondered how Daunte Culpepper and Carson Palmer would play coming back from major knee surgeries. Did we learn anything from their results? Absolutely! Palmer came back because he had a relatively simple, one-structure repair, played a "standup" game and had a line that could protect him. Culpepper had a multi-structure repair that he rushed back from, lost mobility without changing his game, and never seemed to fit into the Dolphins' schemes.

You might think that Donovan McNabb would be more like Culpepper, but when it comes to knees, McNabb's is more like Palmer's. Assume McNabb will be slightly less mobile and that he might be more inclined to hurry a throw. Why the hurry? Because instead of scrambling as McNabb once might have, the knee might give him just enough pause to ... not pause. It's a pattern we saw with Palmer last season until he gained confidence in the knee. I expect McNabb to return to his elite level quickly and without problems. Here's one key -- when McNabb participated in the team's offseason program, he didn't have significant swelling after the workouts. That's a big positive according to one of the physical therapists I consult.

• Having already said that McNabb isn't likely to be this year's version of Culpepper, what the heck can we expect from this year's actual Daunte Culpepper? While we don't know where Culpepper will land, there's one fact we do know that should be utmost in your mind. When Culpepper said he was healthy, both before and after the injury, he flat out stunk. Even if you discount the 2006 stats as injury-depressed, he still had twice as many interceptions as TDs in 2005.

Culpepper has always been erratic, save for those two amazing years in 2003 and 2004. Given Culpepper's injury status, you can't ever expect he'll be the positive-value rusher he once was, which leaves you hoping for a comeback based on the hope that maybe he's got one more season in him like 2004. Even in the most liberal views of quantum physics, it's very hard to go back in time. For fantasy owners and prospective employers, it's time to move on.

• Should we ever worry about the left side of a right handed QB's body? If you're thinking about drafting Matt Hasselbeck, you'd better. While it seems counterintuitive, the left arm is as important to throwing as the right. Think about your favorite QB -- or just look at this picture of Hasselbeck -- and you'll note that the non-throwing arm serves as something of a counterbalance. Film of Hasselbeck shows that he has a tendency to keep his off arm lower than most, which could explain why he tends to hold the ball higher than most QBs.

The offseason surgery shouldn't affect this and, in fact, his normal low position for the left arm may be affected less than most "normal" QBs. The biggest worry is that Hasselbeck will get hit and driven onto that right shoulder, breaking apart the fixes performed and leaving him in a mirror state to Chad Pennington a couple years back. It's a small risk, one that should be considered but that should have little or no real statistical effect. (That means you should be using this at your draft. "Oh, thinking about Hasselbeck? What about his shoulder surgery?")

• I know it's hard to think of Matt Leinart like any other QB, but let's try to ignore his Hollywood adventures. If you focus on what he'll mean to the Cardinals, you'll realize that his left shoulder is going to be carrying a heavy load and that a sprain to that very left shoulder ended his rookie campaign. Leinart didn't need surgery to fix the Grade II sprain and he received a clean bill of health from Dr. James Andrews as well. There's some concern about his weight, but he's never been mobile, so as long as he doesn't come to camp looking more like Levi Brown, no one's going to complain that he's not someone else. There's plenty of concerns for the second-year QB -- like his completion percentage and lack of a running game -- but injuries shouldn't be one of them. Here's a key -- Leinart doesn't sell his play action, so that allows rushers to avoid that small hesitation that Peyton Manning always gets. Guess who gets hit more often?

• I read that they're bringing back the Bionic Woman to TV this fall. I don't remember the original, but the phrase, "We have the technology. We can rebuild," should be a tattoo somewhere on Frank Gore's body. Put it near a scar for maximum effect because he has plenty.

He's had both knees and both shoulders rebuilt and has seemed to come back even better. He had over 300 carries last season and some great stats. The one that should count more than his yards per carry (which was inflated by his big plays) is that he played in all 16 games. Gore's health is about the only thing that can hold him back from even bigger things (fumbling is another), but the acquisition of offensive lineman Joe Staley in the draft and the emergence of Alex Smith as a real NFL QB should help Gore run more and stay in the game. If you've got a top-10 pick this year and aren't at No. 1, you're going to have to consider Gore.

• Everyone is watching Adrian Peterson given his chronic collarbone problems, but what about teammate Chester Taylor? It's hard for me to get excited about a guy who, on my draft board, should be a No. 3 RB and only if you believe he'll hold off Peterson. I have Taylor down in the thirties on my draft board in large part because the evidence doesn't indicate that he can carry the feature load, which is one of the reasons that Peterson was drafted.

Taylor clearly wore down at the end of the season, having only one 100-yard rushing game and another at 99 during the second half last season. After those, he missed a game with sore ribs, the result of all the little hits he was taking. Taylor didn't reach 370 carries last year, but another interesting piece of that research shows that running between the tackles has a much higher cost to a runner than getting outside does. It's simple -- there are bigger guys inside. We've seen Taylor pay that price now and he's not likely to do any better this year, especially if he's splitting time.

• Once labeled injury-prone, it's nearly impossible to shake the tag. NFL careers, especially those of running backs, sometimes don't last long enough to make much more than a first impression. Clinton Portis has shown immense talent when he's on the field, but he's done that less and less. Last season's shoulder and hand injuries were fixed, but the problems don't end there. The injuries allowed Ladell Betts to establish himself and while Portis could be helped health-wise by a timeshare, he won't be helped production-wise.

Worse still, Portis has dealt with patellar tendinitis throughout the offseason, something that could limit his practice time and lead to more opportunities for Betts to impress. Portis has never had the success he had in Denver since moving east, and while he's still only 25, he's playing much older, showing definite signs of wearing down that come with chronic injury and a heavy workload. He's still got the burst, but I don't think he can stay healthy enough to break back into the elite level.

• In baseball, I have Sandy Alomar Jr. as a poster boy. In football, it's Fred Taylor. Thing is, Alomar was never as good as Taylor is when he's healthy. In fact, few backs are. It's a fantasy rule that you stay away from timeshare backs. But with Taylor and his running mate Maurice Jones-Drew, they actually are more than the sum of their parts. Taylor has well known issues staying healthy under a feature load, while MJD isn't big enough to get the benefit of the doubt with most when it comes to durability. It will be tough to get both on draft day, but don't be scared to take just one. Jones-Drew is likely to go higher, but the value that Taylor has will come cheaper. Given how well he played -- and more importantly how often -- Taylor is a mid-round bargain who I think will put up similar numbers to 2006.

Bumps and Bruises: Shaun Alexander is fine. Really. Fractures heal and tend not to recur ... Kevin Jones will start the year on the PUP list. It's no surprise, but don't be scared off by this -- he'll be a late-round steal. He's already running at full speed, which is well ahead of expectations. ... Laurence Maroney cleared his pre-camp physical, so there's at least one positive sign out there for you. To me, he's still too risky to take high. ... You're worried about Byron Leftwich's ankle? Good lord, when he's healthy he's slower than Joe Namath. And I mean Namath now. ... Ben Roethlisberger spent this offseason trying to get the plays into his head rather than trying to knock them out on car hoods. That's a positive. ... Chris Simms is said to be back to full health after last season's splenectomy. As you probably expected, there's no comps for this injury. Jeff Garcia is more of a problem for Simms at this stage.

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