Top breakouts, busts for 2013

Randall Cobb burst onto the scene in his very first professional game after being the 64th overall pick in the 2011 NFL draft. He had a 108-yard kickoff return touchdown and hauled in a 32-yard touchdown pass in Packers' season-opening victory against the Saints. Cobb's 15 standard-league points had owners scrambling for his services on the wire.

Unfortunately for them, Cobb didn't do much the rest of his rookie season. He didn't score even half of his Week 1 total in any of his 14 games after that, averaging just over 2.0 points per game.

So how could anyone have seen Cobb's jump from 44 points in 2010 to 150 last season, 17th among all wide receivers? Were there any clues in his rookie season that could have predicted his success? As a matter of fact, yes.

• Cobb caught 25 of 31 targets in his rookie season, posting the highest catch rate (80.6 percent) of the 117 receivers with at least 30 targets.

• He also averaged 7.5 yards after the catch per reception, fourth-highest in the data set.

• His 8.6 average target depth showed a clear role for him in the Packers' offense as well. Only aging Donald Driver joined Cobb with an average target depth below 11.5 yards, and Driver's role was diminishing in the Green Bay offense.

• Cobb took advantage of his limited third-down opportunities as well, one way to gain favor from a quarterback. Cobb converted 5-of-8 (62.5 percent) third-down targets for first downs, a better percentage than any other Packers' receiver.

In limited action, Cobb proved himself reliable and explosive. Numbers backed him for a bigger role in the Green Bay offense, and he got it in 2012.

Of course, there's no certain way to nail down who will break out or who will bust. However, digging into the numbers behind the numbers can paint a clearer picture. Here are five players with 2012 peripherals that look better (or worse) than their current ESPN Fantasy projections for 2013.

Poised to break out

Ryan Tannehill, Miami Dolphins

Even though he has only 35 career starts at quarterback between college and the pros, Tannehill already has the blitz figured out. Tannehill averaged 8.4 yards per attempt when defenses sent at least five rushers after him, fourth-best among qualified QBs.

The deep ball is no concern, either. Tannehill completed 44.4 percent of passes deeper than 20 yards downfield last season. Only Robert Griffin III (47.1 percent) and Peyton Manning (45.9 percent) were better.

His numbers look even better considering whom he was targeting. Dolphins receivers dropped 5.6 percent of Tannehill's passes, eighth-highest among qualified quarterbacks.

Brian Hartline was the most-targeted Dolphin on downfield throws (24), 13th in the league. Hartline caught 57.4 percent of targets in the first three years of his career (before Tannehill), trailing 76 other qualified wide receivers. In addition, Hartline was clocked at 4.52 seconds in the 40-yard dash, hardly optimal for a big-play receiver. New Dolphin Mike Wallace was clocked at 4.33 at the combine, and brings more of a deep-threat pedigree than Hartline. Wallace has 16 touchdown catches on deep throws since the start of 2010, more than anyone else.

So why is Tannehill barely a top-25 quarterback in ESPN's rankings? He averaged 6.1 yards per attempt against standard pressure (four or fewer rushers), second-worst among qualified QBs. Tannehill's 50.0 Total QBR ranked 26th among qualified quarterbacks. Defenses keyed in on it as a weakness as the season progressed, too. Tannehill faced four or fewer rushers at a higher rate than league average (70.5 percent) in none of his first eight games, but did so in six of his final eight games.

There was cause for concern early, as Tannehill really struggled against standard pressure in his first 10 games. He completed 55.2 percent of passes with a touchdown and five interceptions against four or fewer rushers in those games. Tannehill's 40.7 Total QBR against standard pressure was 33rd among qualified quarterbacks through Week 1-11.

Tannehill's final six games were much better, as he completed 62.5 percent of his passes with six touchdowns and one interception against four or fewer rushers. His Total QBR rank against standard pressure jumped to 16th in that span. His schedule wasn't easy for a rookie quarterback down the stretch, facing the Seahawks, 49ers and Patriots twice (once with Aqib Talib).

Considering Tannehill had 19 starts at quarterback in his entire college career, it's reasonable that he needed 10 games to adjust to NFL defenses.

Now consider Wallace wasn't the only weapon Tannehill added in the offseason. The tight end with the best catch percentage among those with at least 30 targets last year was new Dolphin Dustin Keller (28 receptions on 35 targets, 80.0 percent). Former Dolphin Anthony Fasano's 63.1 catch percentage ranked 26th among tight ends.

Just how big a step will Tannehill take this year? Only slight improvement might not help many owners, but Tannehill is worth gambling on as a QB2.

Chris Ivory, New York Jets

As of this writing, 27 running backs are projected to score more standard points than Chris Ivory this season, surprising given the uncertainty at quarterback for the Jets and the lack of proven options on the roster.

Whoever gets carries for the Jets won't finish the season as the 28th-best running back in fantasy, and Ivory looks to be the favorite, although yet another injury (he's played just 12 games the past two years) -- this time a hamstring -- has kept him sidelined throughout camp at this point. After all, as disappointing or frustrating as Shonn Greene was to own last year, he finished 14 spots ahead of Ivory's preseason projection rank.

Last season, the Jets called designed rushes on 46.4 percent of plays from scrimmage, fifth-highest in the NFL. They weren't elite running the football, but anything was better than when they passed; the Jets' 3.8 yards per rush ranked 23rd last season, compared to 6.4 yards per pass attempt (28th in NFL).

Factor in Mark Sanchez's proclivity for the interception, and they could have run even more. Sanchez threw a pick every 25.2 attempts, ranked 31st out of 32 qualified quarterbacks. Maybe Geno Smith breaks out right away, but the Jets' offense will likely need to run the ball to be effective at least in the beginning.

So the Jets will run, but will Ivory? Bilal Powell and Joe McKnight both failed to seize opportunities last season, prompting the team to acquire Ivory and Mike Goodson in the offseason. All four rushers have at least 112 career rushes, but none have more than Ivory's 256 (all with the Saints), so there's a decent enough sample size to compare here. It should be noted that Goodson still hasn't reported to camp following an arrest of drug and gun charges in the spring, further thinning the ranks.

Even if Goodson shows up, the numbers among this foursome back Ivory pretty strongly, since he averages better than a half-yard per rush more than the other three for his career. Since entering the league in 2010, Ivory has averaged 5.1 yards per carry. How many of the 62 active running backs with at least 200 rushes have a better average than Ivory? Three: Jamaal Charles, C.J. Spiller and Adrian Peterson. That's it. Shonn Greene's 4.0 ranks 42nd over that span, while neither Goodson, McKnight or Powell average better than 4.5 yards per rush in their careers.

It's not finesse running, either, which will no doubt please Rex Ryan and fantasy owners alike. Ivory's 2.4 yards after contact per rush ranks fifth among the aforementioned backs with at least 200 career carries.

His style of running has been effective moving the chains, though some of that may be attributed to letting defenses focus on Drew Brees. Still, Ivory has rushed for a first down on 28.1 percent of his career totes. Neither Powell, Goodson nor McKnight is even at 20 percent. Provided Ivory gets healthy, he's the man to watch in this backfield.

Pierre Garçon, Washington Redskins

It's not hard to see the risk involved with Garçon. He was nagged by a foot injury suffered in the first quarter of the first game of the season, and offseason shoulder surgery only adds to the possible headaches for fantasy owners.

Just don't forget the upside.

Garçon averaged 1.2 receptions for 17.1 yards per quarter played last season, which translates to 76.8 catches for 1,094.4 yards and 6.4 touchdowns for a full season. That brings Garçon to 147.8 fantasy points in a standard scoring league, a projection that would move him from 32nd among wide receivers in ESPN's current projected points to 18th.

Now let's factor in what Garçon played through last season. Garçon tore a plantar plate in his right foot, making accelerating and sprinting difficult. This reportedly affected him all season, meaning he put up those numbers playing through an injury that affected his biggest asset: Speed.

Garçon's injury may not be fully healed by Week 1, but the offseason of rest certainly didn't hurt. His production last year when playing through pain not only demonstrated his skill, but helped him build an obvious rapport with quarterback Robert Griffin III. RG III looked for Garçon often when he was on the field, targeting him 67 times on 190 routes run last season (35.3 percent). That ranked him third in the league among qualified wide receivers, with only Brandon Marshall and Percy Harvin targeted on a higher percentage of routes run.

Garçon had receptions on 23.2 percent of those 190 routes, fifth-best in the league among qualified wide receivers. The only players better than Garçon were Harvin, Marshall, Michael Crabtree and Andre Johnson. Garçon's five catches on 17 red-zone routes bodes well, too. That 29.4 percent rate is best among 74 qualified receivers, showing how Griffin was not looking for Garçon to be just a big-play threat.

Choosing Garçon on draft day is undoubtedly a gamble. However, if the reports from training camp are positive as August wears on, Garçon's potential production is worth it.

Bound to disappoint

Antonio Gates, San Diego Chargers

The days of "Antonio Gates, fantasy superstar" are long behind him. Gates finished 12th among tight ends last year, and a closer examination makes it a surprise he wasn't lower.

There were 10 games last year in which Gates was active and had three catches or fewer. Of the 32 qualified tight ends last season, only Zach Miller, Lance Kendricks, Anthony Fasano, Joel Dreessen and Benjamin Watson finished with three catches or fewer in more games than Gates.

Gates averaged 3.3 catches for 35.9 yards and 0.47 touchdowns per game last season, his lowest averages since his rookie season of 2003 (1.6 catches, 25.9 yards and 0.1 TD). The problems Philip Rivers had last year affected Gates (more on that below), but this is no isolated season.

Gates' involvement with the Chargers' offense has decreased each year since 2009. He was targeted on 17.2 percent of his routes last year, ranked 31st among 32 qualified tight ends. That's been steadily declining from 27.3 percent in 2009, 22.0 percent in 2010 and 20.6 percent in 2011. In addition, his 11.2 catch percentage ranked 30th among qualifiers. Given the inconsistent involvement, Gates needs to do significant damage in the end zone to salvage top-10 value.

That's where it gets even more troubling, though. From 2009-11, Gates was targeted on 31.1 percent of red-zone routes, trailing only Jimmy Graham among tight ends. Last year, Gates was targeted on 21.3 percent of red-zone routes, 22nd among tight ends.

At least Gates made the most of his targets, catching 7-of-10 for six touchdowns. There still may be a little value to owning Gates, whose preseason projection ranks seventh among tight ends, but there should be plenty more than six tight ends who finish better than Gates this season.

Danario Alexander, San Diego Chargers

The physical tools keep making Alexander so tantalizing, but he just can't stay on the field. Alexander has never appeared in more than 10 games in a season, and enters his fourth year as more untapped potential than reliable option.

Alexander arrived in San Diego as a cost-effective replacement option for Vincent Jackson last year, but the Chargers couldn't replicate the downfield success they had with Jackson. Alexander's 7.0 drop percentage was the eighth-worst among 76 qualified wide receivers.

Part of Alexander's problem lies with Philip Rivers. In 2010, Rivers ranked second in the league with a 43.6 completion percentage on throws deeper than 20 yards downfield, averaging a league-high 16.3 yards per attempt. He's regressed in each of the past two seasons, tying for 15th with a 33.3 completion percentage in 2012, while his 10.7 yards per attempt ranked 22nd.

Due to the ineffectiveness, Rivers threw downfield less and checked down more. Rivers had 54 attempts deeper than 20 yards downfield, his fewest in the past five years. He also threw 156 passes at or behind the line of scrimmage, most in the league and at least 50 more than he had thrown in a season since 2008.

Even in a Norv Turner offense last season, Rivers threw 56.4 percent of his throws five yards downfield or shorter. The only quarterbacks who threw short more often were Christian Ponder and Brandon Weeden. He threw 297 passes five yards or fewer downfield, his highest total in the past five seasons and sixth-most in the league. Rivers flat-out missed (over or underthrown) on 14.9 percent of those attempts. The only quarterbacks with higher off-target percentages on short throws than Rivers were Cam Newton, Jake Locker and Ryan Tannehill.

Short passes do not play to the strength of the 6-foot-5 Alexander. He's dropped six of the 49 targets (12.2 percent) in his three-year career on passes five yards or less downfield, the second-highest rate among 94 receivers with at least 40 such targets during the past three years.

Alexander's injury history and drop problems, plus regression from Rivers, are a lot to overcome for Alexander to live up to his projection as the 28th wide receiver.

Editor's note: Alexander suffered a torn ACL on Aug. 6, and will miss the entire 2013 season.

John Parolin is a member of the ESPN Stats and Info group.