Prediction1 — Los Angeles Dodgers2 — Arizona Diamondbacks3 — San Francisco Giants4 — Colorado Rockies5 — San Diego PadresLos Angeles Dodgers Last year's NL West race came down to the final week of the season, with L.A. just edging out the Diamondbacks. This year's race looks about the same, with the Dodgers and D-Backs pacing the division. What really separates the two is L.A.'s great opportunity for improvement; they've got the young talent to take the division by storm.It starts in the rotation with ace Chad Billingsley. The Dodgers will miss Derek Lowe, but Billingsley should be able to step up and do just as well, if not better. Last year, Billingsley posted a 3.14 ERA and struck out 201 batters in 200.2 innings. The only concern here is the big increase in innings pitched in 2008 (65.1 more than in 2007, including the postseason) as well as his 80 walks allowed. The other young stud in the L.A. stable is Clayton Kershaw. Long-term, Kershaw's ceiling may be higher than Billingsley's, but he's still quite young; he just turned 21. But while he may not top 200 innings, Kershaw looked pretty sharp as a 20-year-old rookie last year, managing a 4.26 ERA with 100 K in 107.2 IP. These young aces are backed up by the capable Hiroki Kuroda, who had a fine 2008, and Randy Wolf, added as a free agent for a modest cost. The #5 slot will probably go to young James McDonald, who proved himself capable in the role last year. The only problem will be if the Dodgers insist on starting Jason "Walking Wounded" Schmidt in an attempt to salvage something from his woeful contract.The Dodgers are taking a hit in the bullpen with the loss of closer Takashi Saito, but they have a fine replacement on hand in Jonathan Broxton. And behind Broxton, they've got reliable arms such as Hong-Chi Kuo, Cory Wade and perhaps McDonald if Schmidt ends up starting.The lineup isn't such a sure thing, although it did receive a tremendous boost with the return of Manny Ramirez. Manny won't hit like he did down the stretch last year (396/489/743* with L.A.), but he's a huge upgrade over Juan Pierre (who isn't?). Matt Kemp and Andre Ethier round out a group that may not be very strong defensively, but has the potential to be the best-hitting outfield in the league.* — Slash stats indicate (Batting Average/ On-Base Percentage/ Slugging Percentage)The Dodgers have a star behind the plate in Russell Martin, but they will need to resist the temptation to overwork him. Martin played in 155 games in 2008, a staggering number that took a toll on his offense as the year went on. Joe Torre will have to find more opportunities to rest his young star, although it would be nice to have a better backup than Brad Ausmus.The infield is problematic, but still pretty strong. Rafael Furcal and Orlando Hudson provide great defense up the middle, even if both are starting to show signs of age. James Loney is an All-Star waiting to break out at first, and the only non-star is Casey Blake at third. The Dodgers signed Blake to a silly contract in the offseason, but considering the lineup depth around him, it shouldn't hurt them too much (although they'll regret trading away these guys to get Blake). Any gaps in the middle infield can be filled immediately by prospects Chin-Lung Hu and Ivan DeJesus, Jr.There's still a lot here that can go wrong: injuries, personality clashes, as well as a stronger NL West than we've seen in a while. But the Dodgers are well-positioned to ride their young talent to another postseason berth.Arizona Diamondbacks The Diamondbacks, like the Dodgers, are a team that's relying on its young guns to lead the charge into October. The difference is mainly one of depth; the D-Backs have more holes than the Dodgers, with little help coming up from the farm. But there's still a lot of unfulfilled potential on the club, which could lead to some surprises.The D-Backs begin and end with their 1-2 dynamic pitching duo of Brandon Webb and Dan Haren. Webb is one of the best and most consistent pitchers in the entire league, and Haren isn't far behind them. The only question is what kind of support they'll get along the way. The way things look right now, it will be Doug Davis, Jon Garland and Max Scherzer backing up the big two. Scherzer is young but has great potential. The trouble is with Davis, who is reliable if unexceptional, and Garland, who's just unexceptional. The big drop-off in talent after Webb and Haren means that Arizona relies on them more than ever; if one of them goes down for any real length of time, the team's October hopes go down with them.The great untapped potential — and thus the great hope — lies in the lineup. Arizona has potential All-Stars playing at least four positions, and no one on the team is an easy out. But getting any sort of consistency from their young stars has been a real struggle. The poster boy for this problem is Justin Upton. Upton has as much potential as any young player in baseball; consider that he has two big-league seasons under his belt and is still just 21. The frustrating thing is what he's done in those seasons, which isn't a whole lot. He took a step forward last year after a forgettable rookie campaign, hitting 250/353/463, but he's capable of much more. The big problem is his 121 strikeouts in just 356 at bats. If Upton can improve his plate discipline, he'll hit for a better average and be better able to take advantage of his power.Equally frustrating has been center fielder Chris Young. Young has a great deal of raw power, but his plate approach tends to be all-or-nothing. Young struck out 165 times last year and hit just .248. He did notch 22 homers and 42 doubles, but even that isn't enough to compensate for a .315 on-base percentage. Even a small improvement would go a long way toward making Young a star, especially since his speed makes him a real asset in center field.The veteran of the group is left fielder Conor Jackson. Jackson was moved to left to accommodate the return of Chad Tracy, who was forced off of third base by Mark Reynolds. Both Tracy (durability) and Reynolds (204 strikeouts) have their faults, but Jackson turned in a pretty impressive 2008, hitting 300/376/446. But while he's a good contact hitter with a keen batting eye, Jackson just doesn't have the power associated with a left fielder. He hit 12 HR last year, and his career high is just 15.And then there's the infield, where the only sure thing is shortstop Stephen Drew. Drew took a big step forward in 2008, but has yet to become the all-around star the D-Backs drafted. I mentioned the problems with Tracy and Reynolds above, and second baseman Felipe Lopez is only has a job because of a lucky 43 games with the Cardinals last year.The potential is there for this team to win 90+ games and play in the postseason. But you can't count on another step forward from so many prospects in one year. It doesn't look like the D-Backs can compete with the Dodgers, which leaves them hoping for a Wild Card berth.