Ranking the biggest potential X-factors for each MLB playoff team

These 10 players, overlooked at the start of the season, could end up having a huge impact in October for their teams.

The playoffs begin one week from Tuesday with the American League Wild-Card Game, and all 10 entrants into the postseason tournament have their own stories about how the pieces came together to get here, including the pieces nobody expected to fit.

The Tigers wouldn't be in playoff position without a middle-of-the-order hitter who was cut in spring training by the worst team in baseball. The Orioles wouldn't be here without a slugger they cut themselves after the season began. The Angels' best pitcher came to camp this year with a career minor-league ERA close to five.

Somehow it all came together. The questions became answers. They were the X-factors of winning seasons.

And now the questions are back. Can they keep the magic going in the postseason? Will the best regular-season stories became postseason legends or busts? All eyes are now on these players: These are the biggest X-factors for the teams in playoff position, ranked in order of their impact.

• MLB division and wild-card standings: Sept. 23

1. J.D. Martinez, OF, Tigers

He turned around his career with the help of a secret coach.

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Martinez was hurt at the end of last season with Houston, giving him time to study his swing on video. He didn't like what he saw. Martinez hardly used his lower half, and his bat was in the strike zone for only a brief period, such was the extreme arc to his swing. He studied swings of other players that he wanted to copy, found one he particularly liked, and found out who that player used as a hitting guru. He called up the guru and asked if he would help him. The man said yes.

"He doesn't want his name out there," Martinez said of the secret coach.

Martinez went to the Venezuelan Winter League to try out his swing and mashed. But midway through spring training, citing a logjam of hitters, the Astros, the worst team in baseball last year, released Martinez. He was only 26 years old.

Tigers coach Dave Clark, who knew Martinez from Houston, heard about the release that morning and told manager Brad Ausmus he always liked Martinez and was worth a flier. Ausmus told general manager Dave Dombrowski to look into it. Two days later, Martinez was in Tigers camp — minor league camp. They didn't even bother to bring him to the major league side.

"I didn't see him," Ausmus said. "But I heard about him when he was there. He hit three home runs one day. Honestly? We thought he might be a guy who could give us a power bat off the bench."

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Martinez smashed 10 home runs in 17 games for Triple A Toledo. Detroit called him up. The power bat on the bench became a part-time outfielder who became the full-time leftfielder to provide protection behind Miguel Cabrera and Victor Martinez. He has hit 23 home runs and slugged .570, including 13 homers and a .648 slugging percentage in innings seven through nine.

Martinez still has his holes, like his 120 strikeouts with the Tigers. But he has such raw power and has hit so well late in games that he can turn around a postseason game or series with a swing at any time.

2. Steve Pearce, 1B/DH, Orioles

Where do you find a 20-home run hitter who slugs .557 with a breakout year at age 31? How about a guy who has been released, traded or designated for assignment seven times, who in 2012 once changed teams six times in 10 months, and who was dropped from the team as recently as April?

After a long journey, Steve Pearce finally catching on with the Orioles

When Baltimore designated Pearce for assignment only seven at-bats into his season, it appeared to be only the latest insult in an itinerant career. But the Orioles and Pearce had established such a respectful relationship that it amounted to a little more than a paper move. Pearce wanted to re-sign with Baltimore after it basically kicked him out open up a precious roster spot. He turned down the opportunity to play elsewhere — Toronto claimed him off release waivers — to come back to the Orioles.

What didn't happen with the Pirates, Twins, Astros, Yankees and Orioles the first time around suddenly is happening for Pearce. He is putting down roots.

The guy could always hit, but after moving to a 1970s-style closed stance to help him see the ball better, Pearce has become such a force in the Baltimore lineup that the Orioles don't miss Chris Davis, the slugger who is suspended because of a failed PED test.

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Pearce absolutely crushes lefthanded pitching (1.113 OPS) and does damage against righties, too (.858). He has hit .324 with runners in scoring position — especially impressive for a guy who, like Davis, uses half the field. (Pearce has only six opposite field hits all year, including only one single.)

Pearce has never played a postseason game, and his pull-field approach could be exploited in the postseason. But this guy has been beating the odds all year. You want to bet against him?

3. Josh Harrison, 3B, Pirates

Now even the Pirates are admitting they may have underestimated Harrison. It's been happening to him his whole life, which can be the case when you're only 5-foot-8. He was undrafted, and barely recruited, out of high school in 2005, drafted in the sixth round by the Cubs in 2008 and traded three years later to Pittsburgh, where he was labeled a utility player for three years.

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Now? After finally getting a chance to play everyday, Harrison made the NL All-Star team and became a true impact hitter. He leads the league in hitting (.318, including .340 in the second half) while slugging .500. The Pirates didn't give Harrison an at-bat in the postseason last year. But he plays with so much energy and confidence that his game looks like it's made for the playoffs. He's hitting .372 with runners in scoring position, and while he destroys first pitches (.450), he's also a well-above-average hitter with two strikes (.247).

4. Justin Turner, IF, Dodgers

The signing of a 29-year-old utility infielder with a .260 career average and eight home runs generated little enthusiasm for many of those who follow the Dodgers.

"We took some heat for letting Skip [Schumaker] and Nick [Punto] go," Los Angeles GM Ned Colletti said, "but we wanted to get younger, and we thought we had a younger version of Skip and Nick [in Turner]. We knew he could play all infield positions and we knew he could hit, but I can't tell you we expected him to hit like this. He's been one of our most productive guys, especially in the clutch."

Turner has hit .333 in 64 starts, .325 in 40 games off the bench, .393 as a pinch hitter and .410 with runners in scoring position. He is a weapon every manager wants in the postseason, especially in the NL: a clutch bat who can hit good pitching late in games.

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5. Matt Shoemaker, SP, Angels

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The Angels may have lost strong-armed youngsters Tyler Skaggs and Garrett Richards from their rotation, but they are thriving because of a 27-year-old rookie who throws 91 mph and posted a 4.52 ERA in seven minor league seasons. All Shoemaker does is get better and better, with a confidence that has impressed manager Mike Scioscia. Shoemaker has a 1.87 ERA in the second half, beating the doubters who thought the league would catch up to him.

Shoemaker throws a sinker, four-seamer, splitter and slider with near-enough equal frequency that he is a confusing puzzle to hitters. Assuming he's sufficiently recovered from the strained rib cage that has sidelined him lately, his stuff may play in the postseason — even with heightened scouting reports — because he has so many options.

6. Drew Storen, RP, Nationals

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After blowing Game 5 of the 2012 NLDS to St. Louis, Storen lost his closing duties to free agent Rafael Soriano and slumped to a 4.52 ERA last year. But this year, Storen found magic in his changeup, throwing it twice as often as he ever had before, and he's been so good in the past three weeks he wrested the closing job back from Soriano.

Storen has allowed seven runs all year, including only one in the past two months. He is manager Matt Williams' hot hand. But Storen's strikeout rate isn't eye-popping for a closer (7.1 per nine), and he's less effective with runners on than with the bases empty – which bears watching when he tries to put 2012 all the way behind him this October.

7. Sean Doolittle, RP, Athletics

The A's squandered $10 million on a closer who couldn't close (Jim Johnson), then realized they had a low-walk, high-strikeout, no-nonsense guy for the ninth all along. Lefthanders have almost no chance against him (.118, no walks, 32 strikeouts in 76 at-bats), and righthanders fare only slightly better (.198). Forget worrying about no experience closing games in the postseason; Doolittle's stuff is so good that hitters are batting .082 against him when he gets two strikes on them.

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8. Wade Davis, RP, Royals

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Think about how good Yordano Ventura is: He won the fifth starter's spot in spring training by beating out Danny Duffy and Wade Davis, both of whom have electric stuff. Davis' fastball is up by 3-4 mph since moving from the rotation to the bullpen, though he said a mechanical adjustment intending to store more power on his back leg also has helped. Davis is the first pitcher in history to throw 70 innings with an ERA below 1 (0.90) while not allowing a home run.

The key with Davis is how manager Ned Yost uses him if the Royals make a run. Yost has used Davis for more than three outs only four times all year and not once since May 29. As a former starter, Davis is too good a weapon to limit to one inning.

9. Jon Jay, OF, Cardinals

After poor outfield defense helped doom the Cardinals in the 2013 World Series, GM John Mozeliak traded for ballhawk Peter Bourjos, a move that was supposed to make Jay a spare part, especially with hot prospect Oscar Taveras also moving into a crowded outfield picture. Jay looked like a fourth outfielder through the middle of May, hitting .253, but he soon heated up and won back his everyday job, hitting .316 since then. His .376 on-base percentage for the season would rank in the top 10 in the league if he had enough plate appearances to qualify.

Jay is an odd player in that he plays in the middle of the field even though he doesn't have power (just 22 extra-base hits), speed (six steals in nine tries) or an elite glove. Also, his OBP is helped by a knack for getting hit by pitches. But he does consistently put together quality at-bats against both starters (.304) and relievers (.303).

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10. Joe Panik, 2B, Giants

One of seven second basemen tried by the Giants this year — anybody remember Brandon Hicks or Dan Uggla? — the rookie emerged as a solid starter with a huge August (.379). He cooled a bit in September (.276), but the Giants like the way he plays with confidence, no matter the stakes. He doesn't just hang in well against lefthanders, he rakes them (.342). He has also excelled by batting .400 in close-and-late situations, which are defined by STATS Inc. as being the seventh inning or later when the offensive team is either ahead by one, tied or has the tying run on base, at bat or on deck.