What must go right: Arizona's new ownership is apparently intent on creating a new era -- making concessions to swap unhappy pitcher Randy Johnson, spending above market price to sign pitcher Russ Ortiz and slugger Troy Glaus, and dealing for Shawn Green. The Diamondbacks could be a threat in the NL West if all of their new parts come together and perform (Javier Vazquez, most notably, if he's not traded), and some of the returning players rebound.
What could go wrong: There are potholes all over the place, for a team that went 51-111 last year. Vazquez needs to tinker with his mechanics and raise his arm angle back to where it was before the All-Star break last year. Glaus has to stay healthy, and Luis Gonzalez has to hit. Ortiz is generally regarded around the game as a good innings-eater, but not the rotation leader that the Diamondbacks need him to be. And, in keeping with Arizona team tradition, there is some question about the back end of the bullpen. Greg Aquino, 34 games into his major-league career, was the closer at the end of last season and converted 16 of 19 chances.
The X-Factor: Vazquez was demoted and dropped out of the Yankees' postseason rotation last fall, and that makes it easy to forget that he was an All-Star not too long ago -- like in 2004. He was 10-5 with a 3.56 ERA before the All-Star break, and was everything the Yankees expected him to be. Maybe he'll be unhappy pitching in Arizona, because his stated desire is to pitch for an East Coast team. But Vazquez is accountable and professional, and it's possible he could bounce back and be a terrific pitcher again.
Numerically speaking: The Diamondbacks hit 135 homers last season, tied with Milwaukee for the fewest in the NL, and they scored 615 runs, the fewest in the NL. Randy Johnson probably had those numbers memorized, before he headed out the door.
What must go right: The Braves reloaded their pitching staff this offseason, shifting John Smoltz back into the rotation, trading for Tim Hudson in what might be his last season before he's eligible for free agency, dealing for new closer Dan Kolb. With Smoltz and Hudson leading a rotation that also includes Mike Hampton (9-1, 3.13 after the All-Star break), John Thomson and Horacio Ramirez, the Braves are in position to win the NL East crown again -- assuming they identify some middle relief in front of Kolb, and assuming they hit.
What could go wrong: Gary Sheffield was once the centerpiece of the Atlanta offense, and when he left after the 2003 season, the Braves acquired J.D. Drew, who had Sheffield-like production for the last four months of last season -- before he left, too. The Braves did some small tinkering, such as signing Brian Jordan, but they didn't go out and get a big bat in the offseason, focusing on pitching. They've got some good hitters -- Chipper Jones, Marcus Giles, the surprising Johnny Estrada -- but probably need one more good bopper. The offense may struggle to support the staff.
The X-Factor: Atlanta GM John Schuerholz moves quickly and usually finds a way to get what's needed, and of all commodities on the trade market, a good-hitting corner outfielder is among the easiest to acquire. If the Braves appear through spring training as if they might flounder for runs, with the likes of Raul Mondesi and Jordan not looking good, Schuerholz likely will get busy.
Numerically speaking: Smoltz has 163 career victories, and 200 might turn out to be an important number for his Hall of Fame chances. After serving his time as closer and racking up 154 saves, Smoltz won't be held to the same general 250-win standard that other starters of his era might have had to reach (and Smoltz's postseason record is exceptional). But a career of 180-190 victories might not be enough; 200 could get it done.
What must go right: The Cubs frittered away a lot of the offseason waiting for someone to take Sammy Sosa off their hands, and by the time the Baltimore Orioles made a move, almost all of the healthy and productive players had signed or been traded elsewhere. So the Cubs must now hope that Jeromy Burnitz -- seemingly the last man standing on the free agent market -- will hit like he's in Coors Field, rather than in Shea Stadium, and they'll need solid contributions from shortstop Nomar Garciaparra. Third baseman Aramis Ramirez might have ranked among the five most improved players in the majors last season.
What could go wrong: A rotation that includes Mark Prior, Kerry Wood, Carlos Zambrano and Greg Maddux could be the best in baseball, and Chicago is all but a lock to stay in the playoff chase because of that foursome. But the closer situation is a mess that could undermine the work of that group. Maybe LaTroy Hawkins will finish games, or Ryan Dempster; or maybe Joe Borowski has one more life in a career of extra lives. But they need some stability in this situation, especially because it does not appear as if the Cubs are going to be flush with run production; they've got to be efficient with what they get.
The X-Factor: It wasn't too long ago that Garciaparra was a great -- as in transcendent -- major-league player. He suffered some injuries, developed some anger over his standing with the Red Sox, and it ended badly last season. That chapter is closed now, and maybe Garciaparra will move on mentally and become a great player again.
Numerically speaking: Prior's ERA was 6.17 in July, 5.13 in August, and 2.17 in five starts in the last month.
What must go right: The spring-training issues always seem to be the same with the Reds. Do they have enough pitching? How will they sort out a glut of outfielders? And will Ken Griffey, Jr. stay healthy? Last year, Cincinnati tried 12 different pitchers in a starting role, and no Reds pitcher accumulated 30 or more starts. At least this time around, they've identified a pitcher they will build around -- left-hander Eric Milton. He's got to pitch effectively and lead, the rest of the staff has to develop for Cincinnati to be a factor -- and not necessarily contend -- in the NL Central. Paul Wilson and Ramon Ortiz will occupy two other spots in the rotation, while two spots are up for grabs, and there are two to three spots open in middle relief behind closer Danny Graves and some other veterans.
What could go wrong: The Reds are still developing, still looking for an identity or a particular strength, and they're surrounded by either contending or improving teams in the NL Central. The Pirates have some good pitching, the Brewers have Ben Sheets and a generation of talented position players on the way, and the Cardinals, Cubs and Astros are all laden with proven veterans. The Reds, on the other hand, don't have a foundation set, no great strength, and that could make for a long summer.
The X-Factor: Griffey has played a total of 462 games in his five seasons in Cincinnati, his return to his hometown wrecked by injury. He hit 40 homers in his first year with the Reds, but in the last four years, he's managed no more than 22. If he comes back and proves he's healthy, he'll put the Reds in a better position to deal one of the team's other young outfielders, something that will be needed to upgrade the pitching staff.
Numerically speaking: Last year, the Reds had the highest NL ERA (5.19) for any team other than Colorado, the third fewest strikeouts (992), and their 236 homers allowed was the most in the NL by 38.
What must go right: The Rockies are in rebuilding mode, again; Colorado is like a car stuck chassis-deep in mud, spinning its wheels, looking for some way to get traction, somehow. The Rockies tried developing pitchers in the late '90s, and when some prospects did ascend, they seemed to be quickly swallowed up by the enormous outfield in Coors Field, their confidence suffering as hits fell. Then the Rockies tried signing free agents Mike Hampton and Denny Neagle, and that turned out to be a disaster. So once again, they are trying to build around young pitchers -- and left-hander Jeff Francis is regarded as a super prospect; maybe he and Jason Jennings can be the start of something good. But Colorado's reality is that unless it can find some way to cultivate pitching, it will constantly be in rebuilding mode -- or it'll be forced to go back to the '90s formula, when the Rockies fielded a lineup of mashers who beat up opposing pitching staffs and made the team's homefield advantage more acute.
What could go wrong: A return to the status quo. Nine seasons have passed since Colorado last made the playoffs, and the Rockies have had one winning season in the last seven. Their attendance has dropped from 3.9 million in 1996 to 2.34 million last year; they ranked ninth out of 16 teams last year. The worst thing that could happen is that the steady erosion that has been taking place for almost a decade continues.
The X-Factor: The thin air of Coors Field is always the X-factor. It makes it tough for opponents to play there, but it also makes it tough for the Rockies to develop and maintain and evaluate talent. For example: Jeromy Burnitz slugged 37 homers and drove in 110 runs for the Rockies last year -- and amid an explosion in the free-agent market, he had to settle for a one-year deal with the Cubs. Vinny Castilla drove in 131 runs, slugged 35 homers for Colorado -- and he got a modest two-year deal from Washington. There is an exchange rate applied to everything the Rockies must try to do, and it's really damaging the franchise.
Numerically speaking: Jennings went 16-8 in his first full season, impressively, with a 4.52 ERA -- and his ERA has increased since then to 5.11 in 2003, and 5.51 last year.
What must go right: Josh Beckett lorded over hitters in the 2003 postseason, dominating the Yankees on three days of rest to wrap up the World Series. But Beckett's regular-season contributions during his career have been much more modest -- a career record of 26-26, with an ERA of 3.49. The Marlins have a terrific lineup, with Juan Pierre and Luis Castillo hitting in front of Miguel Cabrera, Carlos Delgado, Mike Lowell and Paul Lo Duca; they've got a lot of reason for hope. But if Beckett and A.J. Burnett don't lead the staff, Florida isn't going anywhere.
What could go wrong: Guillermo Mota has been one of the best set-up men in the game, but now he'll be asked to take over for Armando Benitez, who had one of the most dominant performances in baseball last year. Like many small- and mid-market teams, the weak underbelly of the Marlins is their bullpen, and it could be that Mota won't make a successful transition to closing, or that those replacing Mota will have a tough time ferrying leads to him.
The X-Factor: Burnett threw very hard after returning to the rotation last year, and he seemed to gain command late in the summer; from Aug. 12 onward, he made six consecutive quality starts. And then he had to shut it down. He can be overpowering when he pitches -- but keeping him in the rotation can be a problem.
Numerically speaking: Miguel Cabrera is 21 years old, and already has 174 RBI and 101 extra-base hits in 917 at-bats in the majors. And that's before Carlos Delgado was slotted into the lineup behind him.
What must go right: The Astros must somehow find a way to make up for the offense lost during the winter, with the departure of Carlos Beltran and Jeff Kent and the offseason injury to Lance Berkman. Maybe the offensive juice will come from Chris Burke, and perhaps Mike Lamb can follow up on his solid showing last season when he hit 14 homers and drove in 58 runs in 278 at-bats. But they have to get more from someplace.
What could go wrong: We'll repeat the same line that's been written about Roger Clemens for the last six years -- at some point, he's going to stop being great. At some point, the clock will catch up to him. Andy Pettitte is coming back from injury, closer Brad Lidge is coming off a year in which he shouldered an enormous burden, and Roy Oswalt has broken down in the past. This quartet has to be solid for Houston to stay in the pennant race.
The X-Factor: Lance Berkman could rejoin the Houston lineup early in the season -- sometime in May, perhaps. But that does not guarantee he'll be a great player right away, or that he'll be able to play every day, as he would have before his knee injury. His rate of recovery and his production after he returns will be crucial for Houston.
Numerically speaking: The Astros have one player returning to their lineup who drove in more than 66 runs last season. Jeff Bagwell accumulated 89 RBI.
What must go right: The Dodgers didn't sign Adrian Beltre, the home-grown third baseman who earned the respect of his teammates last year by playing through injuries, and they've effectively replaced him with J.D. Drew, who has played more than 135 games once in his career. L.A. has got to have Drew on the field, producing.
What could go wrong: The best part of the Dodgers last year was their defense. Now Beltre and Alex Cora and Steve Finley are gone and L.A. will go into the season with a set of less than Gold Glove caliber infielders -- Hee Seop Choi at first, Jeff Kent at second and Jose Valentin at third, in a year when they've added Derek Lowe, one of the game's premier ground-ball pitchers.
The X-Factor: The Dodgers have experience in their rotation, with Jeff Weaver, Lowe and Odalis Perez. But they need someone to lead and Brad Penny might be the best candidate, and he was last seen walking off the mound and grimacing, holding his injured right arm late last season. His status will be important.
Numerically speaking: Eric Gagne has thrown 247 innings in the last three seasons, and allowed 145 hits and 49 earned runs, with 365 strikeouts. That's a pretty good weapon at the back end of your bullpen.
What must go right: The Brewers swapped closer Dan Kolb and center fielder Scott Podsednik when their value was high, and in return, they got outfielder Carlos Lee and hard-throwing Jose Capellan. That means Milwaukee has to find a new closer and fill other holes around ace pitcher Ben Sheets and a decent young lineup. Nobody expects them to win 105 games like the Cardinals did last year, but they might get a whiff of the front-runners in the NL Central this summer. And, believe it or not, for the first time in years, the Brewers might be on the verge of having a window of opportunity to contend.
What could go wrong: Sheets's status -- will he sign a long-term deal, or won't he? -- will be a priority for the organization in the months to come; an inability to lock him up would be devastating for the Brewers. It stands to reason that the better the Brewers play this year, the more likely it is that Sheets will feel comfortable remaining in Milwaukee, rather than waiting until after the 2007 season to sign long-term with someone like the Yankees or Red Sox.
The X-Factor: The Brewers have a wave of talented infielders on the verge of reaching the majors together -- first baseman Prince Fielder, second baseman Rickie Weeks and shortstop J.J. Hardy. While Hardy might open the season with Milwaukee, it's possible that Fielder and Weeks will arrive sometime later in the summer, depending on how they fare in the minors and depending on the needs of the team.
Numerically speaking: It's a mind-boggling set of numbers that flew under the radar last year, along with the rest of the Brewers -- Sheets struck out 264 batters and walked only 32 in 237 innings.
What must go right: They've got a lot of bodies who will contend for spots in middle relief, and at least two from the group that includes -- among others -- Scott Strickland, Roberto Hernandez and Felix Heredia have to perform beyond expectations. Otherwise, the relief weakness could sabotage the work of what should be a good rotation. And while Mike Piazza doesn't have to be a star anymore at catcher, he does at least have to be serviceable on defense; otherwise, his throwing problems will become a serious distraction for the pitchers.
What could go wrong: With the exception of first baseman Doug Mientkiewicz, the infielders are all young, and there will probably be days when they make young-player mistakes. Kaz Matsui will be new to his position at second base. And at some point, the Mets will probably need another bat -- something they can obtain in a midseason deal.
The X-Factor: Cliff Floyd has had a decent career, hitting .283 over 12 seasons, and with all that speed in front of him, from Jose Reyes to Matsui to Carlos Beltran, he should be in a position to drive in some runs. Maybe that group will energize him.
Numerically speaking: Beltran already has five seasons of 100 or more runs, five seasons of 100 or more RBI, five seasons of 20 or more homers, five seasons of 27 or more stolen bases. And he's just 26 years old.
What must go right: Something was missing last year, undoubtedly -- something other than the injuries, something beyond the temper of Larry Bowa. It was like the Phillies just didn't know how to win games. You look at the stats, the track records of some of their better players, and you think it should have worked -- and it didn't. Maybe new manager Charlie Manuel -- more laid back than Bowa, for sure -- will have answers. Maybe the middle of the order will put the ball in play more and generate more runs. Maybe Randy Wolf and Brett Myers can put it together. But something's got to change.
What could go wrong: Individually, Bobby Abreu, Jim Thome and Pat Burrell are all capable of producing good numbers. But between them, the trio mustered 309 walks and 390 strikeouts, with 1,530 at-bats, and that's a ton of plate appearances without contact. Maybe they just don't work well together. Neither Cory Lidle nor Jon Lieber would be confused as an impact-type pitcher, but the newly signed starters might have to generate more if Wolf and Myers flounder like they did last year.
The X-Factor: Burrell came back a long way from his horrible '03 season, regaining some balance in his swing. If he puts it all together, with Bowa out and Manuel in, Burrell might be the one guy capable of transforming the Phillies' offense.
Numerically speaking: Wolf, Myers and Vicente Padilla -- three members of what was supposed to be a rotation capable of carrying the Phillies to the playoffs -- combined to go 23-26 last season.
What must go right: If you had Oliver Perez on your fantasy team last year, you know what a great year he had. Otherwise, you might've missed it -- a 12-10 record, 2.98 ERA, 239 strikeouts and 145 hits allowed in 196 innings pitched. That's the stuff of an ace. If Perez delivers again, and Kip Wells comes back from injury, the Pirates will be respectable -- not a contender, but a team that can cause some problems. Josh Fogg went 5-3 with a 3.32 ERA after the break, Jose Mesa converted 43 of 48 save chances, and veteran Mark Redman has been added from Oakland. It's a nice group.
What could go wrong: The Pirates had a marginal offense, anyway, and in order to free up some payroll, they swapped Jason Kendall, who had been a consistent source of hits and runs. Jack Wilson, Craig Wilson and Jason Bay will lead the offense, but in the end, scoring runs could be a problem. And there is this reality: If Pittsburgh does have a serious hole, it is not in a position to go get a veteran (read: expensive) hitter, the way the Cubs or Cardinals or even the Astros would be.
The X-Factor: Wells has great stuff, but he seemed to get into early-inning trouble constantly, and struggled to get himself out of crucial moments; he'd pitch well enough to stay close, but not well enough to win. The Pirates can't get off to a good start quickly -- and they play the Cardinals, Cubs and Astros in 11 out of 13 games in mid-to-late April -- unless Wells steps up.
Numerically speaking: The 26-year-old Bay may have tired late last year, as some young players tend to do; he hit .338 in July, .290 in August, and .232 in the last month, his monthly strikeouts climbing during those periods from 22 to 30 to 33.
What must go right: Mark Mulder, the new St. Louis ace, insisted that he was healthy as he faded in the last two months of last season; scouts have their doubts, and wonder whether he'll have chronic problems. Chris Carpenter led the staff last year before he went down with injury, and Matt Morris seemed to be gassed at the end of 2004. Every team has injury questions, but the Cardinals will have more than most.
What could go wrong: The St. Louis starting pitching was good but not dominant -- and that was good enough, with the incredible support of the daunting Cardinals offense. But Albert Pujols complained during the offseason about nagging injuries, Jim Edmonds turns 35 this season, and Edgar Renteria -- an underrated member of this attack -- is gone. It's possible the Cardinals won't be able to support the pitching the way they did last year.
The X-Factor: Rick Ankiel was once the game's most talented young pitcher, until he was overcome by a throwing neurosis. Now Ankiel has made his way back onto the radar, slowly and steadily. No player has ever come all the way back from this kind of problem, but if Ankiel does, the left-hander could be an impact player.
Numerically speaking: The Cardinals' offense may miss Renteria, but St. Louis will have Larry Walker for an entire season. In just 44 games for St. Louis last summer -- a little more than a quarter of the season -- he racked up 11 homers, 29 runs, 27 RBI and 19 extra-base hits.
What must go right: The Padres could have the best pitching staff in the NL West -- Jake Peavy may be among the five best pitchers in the NL, Brian Lawrence seems to find a way to give the Padres a chance to win, and Woody Williams is a bulldog. But San Diego clearly needs Adam Eaton to take his superlative stuff to the next level, to reduce his inconsistent outings; he had eight outings in which he allowed zero or one earned runs in six or more innings, and yet he finished the season with a 4.61 ERA. He's the key guy.
What could go wrong: The Padres struggled for run production in the middle of their lineup, and Phil Nevin griped repeatedly about the spacious dimensions of San Diego's new field. Nevin's got to get over that entirely, and worry only about driving in runs -- something he'll have an opportunity to do with Dave Roberts, Mark Loretta and Brian Giles hitting in front of him. Ryan Klesko was a bust last year, as well, and the Padres must have a turnaround year from him.
The X-Factor: Third baseman Sean Burroughs plays a power position but hasn't yet hit for power, and now that he's being bumped into the bottom half of the lineup, he could have a chance to drive in runs -- but he can't do so unless he generates more than the 23 doubles, three triples and two homers he mustered last season.
Numerically speaking: Klesko had nine homers in 402 at-bats last season -- seven of those coming after the All-Star break.
What must go right: The Giants will be better defensively in the infield, they've got the closer they so desperately needed last year with the signing of Armando Benitez -- who was the game's best regular-season closer last year -- and their rotation has a chance to be pretty good. But all these ancient players, from Moises Alou to Omar Vizquel to Ray Durham to Marquis Grissom, must stay healthy. In particular, the Giants must keep Barry Bonds and Jason Schmidt healthy. No organization relies as heavily on two players the way the Giants rely on Bonds and Schmidt. "I can't imagine how that team would look if they didn't have Bonds in the middle of that lineup," said one NL scout. "He changes everything."
What could go wrong: Brett Tomko pitched like a beast late last season, helping to make up for the late-season problems that Schmidt had, and Jerome Williams finished well. But the staff has to put it together for the entire season. Alou may do a good job of protecting Bonds and taking advantage of those times when opposing managers work around Bonds, but there's no getting around the reality that the San Francisco outfield defense could be abysmal -- and devastating, in crucial moments. Alou's playing right field in San Francisco -- one of the biggest outfields in baseball -- at this stage in his career makes you cringe.
The X-Factor: Even if they contend in the NL West from start to finish, there's no getting around the fact that the Giants will be a traveling sideshow this summer, while one player will exist in the Big Tent. Bonds will be the focal point from the moment he arrives in spring training, to the day he passes Babe Ruth in the all-time home run chase, to the last day of the season. The Baltimore Orioles had a comparable situation in 1995, as Cal Ripken neared the consecutive-game record, and some members of that staff thought the team, as whole, was affected -- distracted, almost.
Numerically speaking: Bonds needs 11 more homers to tie Babe Ruth, and 52 more to reach Henry Aaron. He also needs 270 hits to reach 3,000, 157 RBI to reach 2,000, 198 walks to reach the unimaginable number of 2,500. And -- by the way -- he's got 506 career steals.
What must go right: They are the only NL East team not projected to be part of the division race, and the Nationals' small pod of good players -- Jose Vidro, Livan Hernandez, Brad Wilkerson and Cristian Guzman -- must stay healthy and perform to ensure that Washington is not steamrolled as the old Senators were. Because they play so many games within the division, the Nationals undoubtedly will have an impact on the NL East race; the four contenders will treat games against Washington as must-win contests, in the same way the Yankees and Red Sox have looked at their Tampa Bay games as must-win -- and there's a danger in that.
What could go wrong: Undoubtedly, there is going to be word of some stadium snafus when the Nationals play their first home games at RFK; the delay in closing the deal with the city greatly reduced the Nationals' time to prepare properly. But few will expect perfection in 2005 -- either at the ballpark, or from the flawed team itself.
The X-Factor: Washington general manager Jim Bowden is not a patient man; his nature is to make moves, shake things up, take chances. He'll have to work through some restrictions, because Major League Baseball still operates the team, but Bowden is not going to let the Nationals fly under the radar all season -- he'll be making deals.
Numerically speaking: Twelve of Washington's first 19 games are on the road, and all but three of their April games will come against NL East opponents, so Bowden will get an early read on just how competitive the Nationals will be in what should be a rough division.
Buster Olney is a senior writer for ESPN The Magazine. His book, "The Last Night of the Yankee Dynasty," is a New York Times best seller and can be ordered through HarperCollins.com.