Oh, rookies. Why must you vex us?
Last year, Knowshon Moreno, Beanie Wells and Donald Brown were ESPN's three favorite rookies for fantasy football. And they finished 18th, 31st and 54th, respectively, in fantasy points among rushers in 2009. No rookie finished among the top 60 in all of fantasy. Gosh, that was a lot of pixel dust spent for very little value, wasn't it?
That's not to say rookies never contribute. In '08, Matt Forte, Steve Slaton and Chris Johnson were all top-11 running backs. Eddie Royal was a top-20 receiver. In '07, some dude named Adrian Peterson was the No. 3 rusher. But it's hard -- really hard -- to look at a first-year player and claim he's got instant fantasy-starter value. Talent has to meet opportunity, with a whole lot of luck mixed in, too. Here are the best candidates for '10:
1. Ryan Mathews, RB, San Diego Chargers: The clear preseason favorite to lead rookies in fantasy scoring, Mathews looks like an early-down starter right away, with Darren Sproles operating as a third-down back and all-around threat. That said, I think some are overvaluing Mathews. He was the NCAA's leading rusher last year and is a good player, but his talent is not sublime. LaDainian Tomlinson's grousing about the Chargers' offensive line last year was probably sour grapes, but if it wasn't, that's a problem. And Mathews is a guy coming off a 276-carry season his last year at Fresno State. I'm not saying you shouldn't want him on your team. But I think he comes with more risk than those who say he's a borderline first-round fantasy pick would have you believe.
2. Jahvid Best, RB, Detroit Lions: Best has had elbow, shoulder and hip surgeries, plus his collegiate career ended early after a concussion. But he's impressed his pro coaches so much this spring and summer, it looks like he'll be an every-down player, too, especially with Kevin Smith likely to begin the year on the PUP list. If Mathews comes with a bit of risk, fantasy owners should receive a complementary team of actuaries after drafting Best, yet if he stays healthy, this kid could be a big-play threat on the order of Chris Johnson. True, his health and his offensive line are in question. But his quickness and speed aren't.
3. Montario Hardesty, RB, Cleveland Browns: Hardesty has already undergone three knee surgeries and has the whiff of a collegiate "one-year wonder" about him, but the Browns couldn't have raved more about how much they thought of him during minicamps, which isn't always the case for Eric Mangini teams when it comes to rookies. A bruiser at 225 pounds, Hardesty makes a fine tandem with Jerome Harrison, which could lead to a frustrating fantasy situation. Hardesty does seem like the better bet for shorter touchdowns, though, if he can stay healthy.
4. C.J. Spiller, RB, Buffalo Bills: Spiller was my favorite rookie going into the draft, but landing in Buffalo did him no favors. Fred Jackson is a very good player and may lead the team in between-the-tackles carries, and for now Marshawn Lynch is also around. But Spiller has home-run speed, and the Bills will line him up in several spots to get him in mismatches. Plus he's likely one Jackson injury away from a starting gig, albeit behind what might be the worst offensive line in the NFL.
5. Dez Bryant, WR, Dallas Cowboys: One dinner with Deion Sanders and a few tardy slips shouldn't have lowered opinions on Bryant. Rookie receivers are rarely fantasy factors, but I'll make an exception for this big, fast, game-breaking player. At 6-foot-2 and 225 pounds, Bryant runs in the mid-4.4s and has otherworldly after-the-catch abilities. Folks who were high on Michael Crabtree last year before his holdout should be even higher on Bryant: He's faster, is as much of a playmaker and lands with a much better offense and more consistent quarterback. He could beat out Roy E. Williams and start in Week 1.
6. Ben Tate, RB, Houston Texans: Tate had one dominant collegiate year and then lit up the NFL combine this spring, so forgive me if I don't turn cartwheels at the notion of his rookie year. Yes, he lands on a team with a great passing offense that's been searching for a consistent big back for years, and yes, the Texans run a one-cut blocking system that should suit Tate's style. But Tate has battled a hamstring injury all spring and summer, allowing Arian Foster to reassert himself into the starting lineup. Injuries will likely wind up settling this situation, but for now, it looks like a three-headed attack, with Steve Slaton also potentially in the mix.
7. Golden Tate, WR, Seattle Seahawks: The other Tate could start right away, either outside or in the slot, and he's a fabulous open-field runner after the catch. But his issues should ring familiar to Seattle fans: Do you trust Matt Hasselbeck or Charlie Whitehurst? I don't, which means I can't find a reliable fantasy starter in this receiving corps. I like Tate's career upside quite a bit, because despite his relative lack of size, he's got a toughness that reminds me of the Carolina Panthers' Steve Smith. But for now, it's hard to view him as a real threat to break into fantasy starting lineups.
8. Mike Williams, WR, Tampa Bay Buccaneers: Tampa's minicamps illustrated how thin the Bucs' receiving group is, and gave Williams a golden opportunity to start as the team's deep threat right away. Of course, Williams has kicked away opportunities before; he missed one year at Syracuse because of an academic suspension, and then quit school the next season because another suspension loomed. You would be correct in raising the question of whether he's got anything close to the maturity needed to excel as a first-year player. But Williams has skills, and at the moment, he looks like Tampa's starting flanker.
9. Demaryius Thomas, WR, Denver Broncos: Comparisons to Calvin Johnson aren't fair; Thomas and Megatron are both big and went to Georgia Tech, but Thomas isn't as fast and isn't nearly as polished as Johnson was coming out of college. Eventually, it's possible that Thomas replaces Brandon Marshall in the Broncos' flanker role and becomes the same kind of big-bodied terror. In the short term, though, there are worries about his pro readiness -- coming as he does from a run-first collegiate system -- as well as his fractured foot, which caused him to miss predraft workouts and some of minicamp. To begin the year, he looks like Denver's third receiver, behind Jabar Gaffney and Eddie Royal, though that's subject to change.
10. Arrelious Benn, WR, Tampa Bay Buccaneers: He has all kind of long-term potential, but this year Benn joins an inexperienced offense in which Josh Freeman's accuracy is a major question. In addition, news out of Tampa indicates that Benn wasn't able to partake in much of minicamp this spring because of an ankle injury, and he also missed time last season at Illinois with an injury to the same ankle. Mike Williams looks like the deep threat, and if the Bucs don't mind the idea of starting two rookies as outside receivers, Benn could be the possession guy.
11. Dexter McCluster, WR, Kansas City Chiefs: Is he a receiver or a running back? The Chiefs announced McCluster as a receiver after April's draft, but he should play all over and is a feared -- if undersized -- weapon. But with Jamaal Charles and Thomas Jones entrenched ahead of him in the backfield, and Dwayne Bowe and Chris Chambers possessing far more size and experience, it's legit to wonder whether McCluster will get to touch the ball enough on a weekly basis to be worth owning in fantasy.
12. Toby Gerhart, RB, Minnesota Vikings: Minnesota was a rough landing place for Gerhart, because Adrian Peterson should dominate the offense once more. The Heisman runner-up isn't a pass-catcher, so he's not a Chester Taylor replacement; he'll likely be AP's handcuff this year, but not much more. It'll take a Peterson injury for Gerhart to have independent value.
13. Anthony Dixon, RB, San Francisco 49ers: Frank Gore is still the workhorse in San Francisco, but the bruising Dixon can get in the mix during his rookie year. He could pass Glen Coffee on the depth chart and perhaps score a few short-yardage touchdowns, though Dixon did miss a few weeks this spring because of a hamstring injury.
14. Joe McKnight, RB, New York Jets: Leon Washington is gone from Gotham, so McKnight inherits his role as a scat back, receiving option, special-teams maven and all-around pain-in-the-butt for opposing defenses. If Tomlinson performs well, though, McKnight's playing time will be limited. But honestly, I don't really expect all that much out of LT. I don't believe McKnight would be a good Shonn Greene handcuff, but he may be enough of a drain to be a fantasy pest.
Deeper sleeper rookies
Sam Bradford, QB, St. Louis Rams: He's the best of the rookie quarterbacks (who include Jimmy Clausen, Colt McCoy and Tim Tebow), but there isn't enough talent around him, especially on an offensive line that's already almost impossibly banged up. Although he's got a good chance to start Week 1, outside of a dynasty league there's not much reason to draft Bradford.
Jermaine Gresham, TE, Cincinnati Bengals: Right now he looks like the best of the rookie tight ends for '10 (that list includes Aaron Hernandez, Rob Gronkowski, Ed Dickson and Dennis Pitta), but that's mainly because he seems to have a starting gig to himself. If his knee is right, Gresham could add a new, vertical dimension to a stagnant Cincy pass game.
Jonathan Dwyer, RB, Pittsburgh Steelers: The backup role behind Rashard Mendenhall is there for the taking, and Dwyer might oblige. Considered a second- or third-round talent leading up to the draft, he lasted until the sixth because of concerns about the fact that he didn't play in a pro-style collegiate offense.
James Starks, RB, Green Bay Packers: In his rookie year, Starks is likely to focus on special teams for Green Bay, but he's a good enough all-around player that a strong training camp might put him in competition with Brandon Jackson for the right to back up Ryan Grant. Certainly, he'd appear to already have more reliable pass-catching hands than any other Packers back.
LeGarrette Blount, RB, Tennessee Titans: LenDale White is gone from Tennessee (and perhaps the NFL) and Javon Ringer isn't a banger, so there's an opportunity here for the giant Blount (238 pounds) to become a short-yardage complement to Chris Johnson. He isn't fast and runs too upright, but Blount can dish out a hit as well as take one.
Charles Scott, RB, Philadelphia Eagles: Scott is already Philly's No. 3 back behind LeSean McCoy and Mike Bell, and based on Bell's injury experience last year, it's not a stretch to imagine Scott working his way into shorter down-and-distance situations at 220 pounds during his rookie season.
Deji Karim, RB, Jacksonville Jaguars: He's big (210 pounds) and fast (4.37 40), which makes the small-college Karim an interesting developmental project. Rashad Jennings is the current backup to Maurice Jones-Drew, but Karim could change that in short order.
Brandon LaFell, WR, Carolina Panthers: LaFell's draft prospects were brighter before his disappointing senior year, but he can be a good red zone threat right away if he's in there. He doesn't have deep speed and too often showed shaky hands in his final year at LSU. Yet there's tons of opportunity in that Carolina receiving corps (especially in light of Steve Smith's broken arm), and LaFell and fellow rookie (and converted quarterback) Armanti Edwards may take advantage.
Jordan Shipley, WR, Cincinnati Bengals: Reports out of Cincy indicate that Shipley is in the mix along with Andre Caldwell to be the Bengals' third receiver. A super-reliable route runner with good hands, Shipley lacks separation speed but doesn't need it if he finds a Wes Welker-style role in the NFL. That's a lofty goal for his rookie year, but hey, ya gotta dream big.
Taylor Price, WR, New England Patriots: Price was a pre-draft favorite of mine, and he landed on a team that doesn't mind playing the most deserving guy, even if he's a small-school rookie. The odds are that Torry Holt, Brandon Tate, Julian Edelman and (eventually) Wes Welker will stay ahead of Price. But his is a name to remember.
Mardy Gilyard, WR, St. Louis Rams: A collegiate playmaker with great after-the-catch skills, Gilyard will be a special-teams factor in St. Louis right away, and could get in the mix as a slot receiver, too. But that Rams offense doesn't look like it can support one fantasy-ready receiver, let alone three or four.
Marcus Easley, WR, Buffalo Bills: He toils for what looks like an awful offense, but only the unimpressive James Hardy and Steve Johnson are ahead of him in a battle to start opposite Lee Evans. It's likely that Easley uses his rookie season for developmental purposes, but he's got that size/speed combo to one day be a star, if he works at it.
Carlton Mitchell, WR, Cleveland Browns: Like Easley, Mitchell is a freakish athletic prospect who'll work in what looks to be an awful passing offense, and he probably needs at least one full NFL season to get his feet under him. Again, though, the depth chart ahead of him in Cleveland isn't particularly star-laden.
Damian Williams, WR, Tennessee Titans: Williams was a productive collegiate player who figures to feature in the return game during his rookie season, as he learns behind Kenny Britt, Nate Washington and Justin Gage during his rookie year. Whether or not you believe in his long-term future may depend on how well you think USC receivers can adapt to the NFL.
Christopher Harris is a fantasy analyst for ESPN.com. He is a six-time Fantasy Sports Writers Association award winner. You can ask him questions on Facebook.