Some special seasons, it seems, come out of nowhere.
Few expected rookie Jonathan Papelbon to take to the Boston Red Sox closer's role as well -- and as quickly -- as he has. The same goes for Dan Uggla, hardly the most highly regarded of the Florida Marlins' slew of rookies, yet, so far, the most productive.
Those kinds of astounding rookie seasons are rare indeed.
It's far more common for players to take some time before completing their learning curve. There are false starts, return trips to the minor leagues, frustrating slumps and perhaps even a change of organization.
We've picked five players who have made it this season, but only after encountering some roadblocks and detours. They are listed alphabetically.
Brandon Phillips, 2B, Reds
When the Cleveland Indians dealt Bartolo Colon to the Montreal Expos in June of 2002, Phillips was thought to be the centerpiece of the six-player deal for the Tribe. Instead, Phillips turned out to be a bust.
In his first full season in Cleveland (2003), Phillips hit just .208 and infuriated the organization with his cocky attitude. Over the next two seasons, Phillips languished at Triple-A and played a grand total of a dozen games for the Indians.
Phillips was out of options this spring and a Reds scout pestered Cincinnati GM Wayne Krivsky into taking a flyer on the infielder.
"I kept coming back to the same thing,'' Krivsky told reporters earlier this season. "He was young and talented and might need a change of scenery. He has good quickness and range and good hands and could turn a double play. Finally, I said, 'You've got to take a chance on someone this young  and [talented].''
Now, Phillips, much like his team, is enjoying a season no one could have anticipated, hitting .312 with seven homers and 42 RBI.
No one questioned his tools, or his sleek 6-foot-5-inch, 200-pound frame. But there was something undeniably absent. Rios was often too happy to hit the ball the other way and his power numbers suffered.
"He was hitting straight up and down,'' recalled general manager J.P. Ricciardi, "because he has this three-part swing. By the time he got to the ball, he couldn't get his hands through the zone.''
The Jays had tried last season to tinker with Rios' swing, but the outfielder was understandably reluctant.
"When you're surviving at the major league level,'' Ricciardi said, "it's hard to make those adjustments. You don't want to go backward.''
Instead, Rios overhauled his swing last winter, eliminating the hitches and it has resulted in his pulling the ball much more. The improvements have been obvious: Through Tuesday, Rios was slugging .602 and had posted a career-high 15 homers.
"He deserves a ton of credit,'' said Ricciardi.
Freddy Sanchez, 3B, Pirates
Despite some good Triple-A numbers at Pawtucket, the Red Sox weren't sure that Sanchez was ever going to hit enough. One member of the organization projected him as Chris Gomez -- a competent major leaguer, but hardly a star.
Sanchez's career has been one of obstacles. He was born with a club foot and in 2003 developed severe ankle tendinitis, which required surgery, costing him almost two full seasons.
The Pirates signed Joe Randa as a free agent last winter, but when Randa went down with a foot injury on May 1. Sanchez stepped into the third base position and made the most of the opportunity.
Now in his third season with the Pirates, Sanchez has blossomed, hitting .355, second in the National League, though his power has yet to come (four homers, 37 RBI).
A few weeks ago, GM Dave Littlefield said Randa would again be the starter once he got healthy. But as Sanchez kept hitting as Randa's replacement, Littlefield was forced to change course.
"This isn't my best or worst or anything,'' said Sanchez of his breakout season. "I'm playing the way I've always known I could play when I'm healthy.''
Nick Swisher, OF/1B, A's
Swisher, like Youkilis, first came to the attention of baseball fans in Michael Lewis' book "Moneyball."
Last year, his first full season in the big leagues, Swisher struck out exactly twice as much as he walked (110-55) and hit just .236.
This season, Swisher has learned to be more selective while not losing his aggressiveness.
"He's swinging at more strikes and playing under control a little more,'' said a longtime American League scout. "He was always raised in that "Moneyball" environment and I think he kind of rebelled against that. Now, I think he's controlling himself better and he's shown more power [19 homers]. I don't think anyone expected this power production. But he's being selective and he's having one of those years.
"He's also made some changes in his swing. He's not uppercutting all the time like he used to and he's using the whole field and presenting a lot of different looks to pitchers.''
Kevin Youkilis, 1B, Boston
After making his major-league debut in 2004, Youkilis rode the Boston-Pawtucket shuttle often last season, flitting between the big leagues and Triple-A thanks to an inexhaustible supply of options.
This season, the Sox had Youkilis penciled in as their primary first baseman, a shift across the diamond from his standard position at third base, now occupied by rebounding veteran Mike Lowell.
For insurance, they signed J.T. Snow and still were scouring for available first basemen as recently as spring training. As it's turned out, their fears were misplaced.
Youkilis has been a revelation. He's hit everywhere in the lineup except third and ninth and has compiled an on-base percentage of .434. While leadoff man Coco Crisp missed almost two months with a broken finger, Youkilis filled in nicely at the top of the batting order.
"He can hit anywhere in the lineup and be comfortable and you can't say that about many players,'' said manager Terry Francona. "He's got great knowledge of the strike zone, which means he doesn't give away at-bats or get himself out. And he's starting to really drive the ball [nine homers] and I think he's only going to get better in the power department.''
What's more, Youkilis has provided stellar defense at first, proving adept at scooping low throws while displaying good range around the bag. He made Snow, a six-time Gold Glove winner, irrelevant. Earlier this week, Snow was designated for assignment.
Sean McAdam of The Providence (R.I.) Journal covers baseball for ESPN.com.