Continuing the theme started last week of ranking the top five teams at a given position, we move on to starting rotations. Unlike with outfields, there is a lot more room for debate and diverging methods of evaluation with pitchers. Do you consider results only, even though they might be warped by luck, park factors and defense? Do you consider pitcher-dependent results only (strikeouts, walks, ground/fly balls)? Personally, I will be using the latter method, but would love to hear your thoughts and disagreements in the comments. Without any further delay, let's unveil my top five starting rotations in baseball.

Philadelphia Phillies

The Phillies have had baseball's best rotation dating back to 2010, but their grip has been slowly weakening. Roy Halladay, battling a right shoulder injury, had his worst season as a major leaguer since 2000, finishing 2012 with a 4.49 ERA. His strikeout rate fell to its lowest point since 2007, his walk rate rose to its highest point since 2004, and his average fastball velocity fell to a career-low. With an aging, injury-prone, declining Halladay, can the Phillies still have baseball's best rotation?

With Cole Hamels and Cliff Lee, the answer to that question is yes. They are two of baseball's three best left-handed starters (the other being Clayton Kershaw). Hamels, the recipient of a six-year, $144 million contract extension signed last July, has been nothing short of rock solid for the Phillies since making his debut in 2006. Last season, Hamels had the fourth-largest gap between his strikeout and walk rates (19%, 6%) among all qualified starters, illustrating that the lefty both has elite bat-missing capabilities and pristine control. Perhaps the scariest fact about Hamels, though, is that he is only 29 years old. Considering everything he has already accomplished, knowing that he could continue to get even better must be scary for opposing National League hitters.

Ignore Cliff Lee's 6-9 record: He's still one of baseball's best starters. AP Photo/Marcio Jose Sanchez

As good as Hamels is with strikeouts and walks, his teammate Lee is even better. Lee had the second-largest gap between the two rates (24%, 3%) among all qualified starters last season and has consistently been among the best in that area dating back to 2008. In fact, his 10.3 strikeout-to-walk ratio in 2010 is the second-best in baseball history, trailing only Bret Saberhagen's 11.0 in the strike-shortened 1994 season.

Lee was the target of criticism through the first half of the season, carrying an ERA north of 4.00 through June. Ultimately, he was simply the recipient of bad luck and when that bad luck turned around, he posted a 2.44 ERA between the start of July and the end of the season, reestablishing himself as one of baseball's most fearsome starters.

Once you get past the trio of Cy Young candidates, the Phillies' rotation doesn't look so scary. Kyle Kendrick and John Lannan are known as two of baseball's more contact-friendly starters, but both have the potential to be solid starters. Kendrick made huge strides last season, bumping his strikeout rate up from 12 percent to 17 percent, which helped him finish with a 3.90 ERA. Lannan induces a lot of groundballs. His 53 percent groundball rate dating back to 2008 is the 12th-highest among qualified pitchers in that span of time. He might not miss bats much and he might not have the best control, but Lannan succeeds by getting batters to roll over on his pitches.

Defense will be a concern for the Phillies' pitching staff throughout the upcoming season. The additions of Youngs Michael and Delmon, an outfield platoon of Domonic Brown and Darin Ruf, and Ryan Howard at first base, will make for some shoddy run prevention (and comedy). If the Phillies' rotation doesn't live up to its potential, it will likely be because of the defense.

Tampa Bay Rays

No James Shields? No problem. Leading the staff is defending AL Cy Young award winner David Price. The 27-year-old lefty has already accomplished so much in his young career, but there is the scary possibility he gets better and better. In 2012, Price's strikeout and walk rates hovered around his career averages, but his groundball rate spiked at 53 percent. This was a result of throwing more pitches lower in the zone. According to ESPN Stats & Info, in 2011, Price threw 31 percent of his pitches down in the strike zone, but increased that to 39 percent last season. Price already has the arsenal (which includes a fastball that consistently sits in the mid-90s), but if he can continue to master pitch location, he could become nearly unhittable.

Jeremy Hellickson is the Rays' No. 2 behind Price. Many sabermetric-friendly analysts thought he was going to regress heavily in 2012, but as we discussed here before the season, Hellickson has some nifty batted-ball skills. His BABIP did regress a bit as predicted (38 points), but was still the sixth-lowest among all qualified starters. While not a groundball or pop-up maven, Hellickson simply induces weak contact in general with a fastball-change combination that keeps hitters off-balance. The two pitches accounted for more than four out of every five pitches he threw in 2012, with a speed differential of nearly 12 mph. Hellickson finished with a 3.10 ERA, and it is safe to bet on him finishing somewhere in the same neighborhood in 2013.

Matt Moore posted a 3.01 ERA after the All-Star break in 2012, with 79 K's in 77 2/3 innings. Joy R. Absalon/US Presswire

The Rays' rotation gets interesting here. Youngsters Matt Moore and Alex Cobb, 23 and 25 years old respectively, make up the middle of the rotation. Moore missed nearly as many bats as Price with his 23 percent strikeout rate. Although his control still needs plenty of work, his ability to get strikeouts gives him a margin for error. Cobb doesn't have Moore's bat-missing skills, but induced a Derek Lowe-esque amount of groundballs in his 136.1 innings in 2012 -- nearly 59 percent, the second-highest rate among all starters (minimum 130 innings), behind only Trevor Cahill. Cobb also displayed great control with his seven percent walk rate.

The last spot in the rotation is up for grabs. The Rays could trade Jeff Niemann, an underrated innings-eater with good control. Niemann enters his final year of arbitration after the season, when he will get a raise on his current $3 million salary. In the event Niemann is moved, 24-year-old Chris Archer would get the final spot in the rotation. Archer has always struggled with command, but missed bats at an incredible pace in his 29.1 innings last season. Between the two, Niemann is the known quantity while Archer has the much higher ceiling, leaving the Rays with an interesting decision to make before Opening Day. No matter what happens, though, you can expect the Rays to have a formidable rotation.

Detroit Tigers

It is no surprise the Tigers would be on such a list. Behind ace Justin Verlander, one of only two players in baseball history to win the Rookie of the Year, Cy Young, and Most Valuable Player awards, the Tigers will be close to unbeatable one out of every five days. Verlander has displayed incredible durability, tossing at least 200 innings in six consecutive seasons (220-plus in each of the past four!) with his fearsome arsenal of pitches. A mid-90s fastball, a knee-buckling curve, and deceptive changeup helped Verlander post the AL's third-highest strikeout rate last season (25%). Power pitchers usually have to sacrifice some control to generate those strikeouts, but Verlander also had the fifth-highest separation between his strikeout and walk rates last season (19%). There's a reason why he is a perennial Cy Young candidate.

Many of the best rotations have unsung heroes. For the Rays, it was Hellickson last year. For the Tigers, it was Doug Fister. The right-hander, soon to be 29 years old, boosted his strikeout rate from below 15 percent with the Seattle Mariners to over 20 percent last year with the Tigers. Combine that with his usual pristine control and an elite 51 percent groundball rate, and you have a guy who couldn't have frustrated opposing hitters more. Between 2011-12, he has a combined 3.10 ERA, which might come as a shock as he is among baseball's most underrated pitchers.

The Tigers rotation starts to get into top-heavy territory with the Phillies now, with Anibal Sanchez as their No. 3. Sanchez, acquired last July in a trade with the Miami Marlins, would be an ace on more than a few staffs and a No. 2 on even more, but the Tigers are loaded. Once slagged for his inability to stay healthy, Sanchez has made at least 31 starts in three consecutive seasons with an ERA that has ranged between 3.55 and 3.86. Twenty-nine years old on Opening Day, Sanchez has made strides since his early days with the Marlins, dropping his walk rate down to six percent last season. He doesn't have Verlander's frightening velocity, but has just enough to complement his ability to mix pitches.

Max Scherzer went 8-2 with a 2.69 ERA in the second half in 2012. AP Photo/Matt Slocum

Max Scherzer slots in at No. 4, and like Sanchez, he would rank a lot higher with many other rotations. Despite missing bats at an elite rate (the highest strikeout percentage among qualified major league starters at 29 percent) and walking very few hitters last year, leading to baseball's highest strikeout and walk rate differential, Scherzer finished with a 3.74 ERA, which included a 4.98 ERA through the end of June. By itself, we might label his .333 BABIP last season a fluke, but he has a .312 career average and was at .314 in 2011 and .308 in 2009. There is no doubt Scherzer has elite stuff, but he hasn't yet utilized his talent to its fullest potential. Few teams can claim that their No. 4 has Cy Young potential.

Like the Rays, the Tigers could make a trade to settle their No. 5 spot. Rick Porcello was in trade rumors throughout the offseason, but as of right now, he has the "leg up" on Drew Smyly for the final spot in the rotation according to general manager Dave Dombrowski. Porcello, the Tigers' first-round pick in 2007, has been a disappointment, sitting with a career 4.55 ERA. On the bright side, he made some very incremental improvements last year in all of the areas that are great for pitchers: strikeouts, walks and groundballs. Nevertheless, Smyly looks like a much more reliable option going forward. He finished with a 3.99 ERA in just under 100 innings last season, striking out 23 percent and walking eight percent. He doesn't have Porcello's groundball tendencies, but it won't matter much in spacious Comerica Park.

Washington Nationals

How scary is this? Dan Haren, a 10-year veteran with a career 3.66 ERA and a three-time strikeout-to-walk ratio leader, is listed as the Nationals' No. 5 starter on their official website. The Nats signed Haren to a one-year, $13 million deal two months ago.

At the top, of course, is 24-year-old Stephen Strasburg. Despite having been shut down before the postseason began in October, the right-hander was one of the biggest reasons the Nationals won 98 games and dethroned the Phillies. His 30 percent strikeout rate was higher than Scherzer's, and the highest rate by a starter with at least 150 innings since Erik Bedard in 2007. Feel sympathetic for NL East hitters who have to see him and his 90-mph "changeup" 18 times a season.

Strasburg's change-up averages 89 MPH. From 2009-12, 38 starting pitchers have fastballs with lower average velocity. — Bill Baer (@CrashburnAlley) January 29, 2013

Despite allegations of performance-enhancing drug use, Gio Gonzalez remains the Nats' No. 2. Having finished third in NL Cy Young balloting behind R.A. Dickey and Kershaw, Gonzalez posted a 2.89 ERA in 199.1 innings with a league-leading K/9 (9.3) and league-low HR/9 (0.4). At 27 years old, the lefty had been traded a whopping four times before landing with the Nationals: from the White Sox to the Phillies, from the Phillies back to the White Sox, from the White Sox to the Athletics, and from the Athletics to the Nationals. And that was despite ranking in Baseball America's top 100 prospects from 2006-09! Nationals fans should be very happy that GM Mike Rizzo found such a gem.

Jordan Zimmermann was quietly one of baseball's best starters. In 195.2 innings, the right-hander finished with a 2.94 ERA but did not show up with even a single point in NL Cy Young balloting. Zimmermann posted the eighth-lowest walk rate in the NL. Working alongside Zimmermann in the middle of the Nats' rotation is Ross Detwiler, a soon-to-be 27-year-old lefty with a penchant for inducing grounders. He is similar in a lot of ways to Lannan, both with the above-average groundball rates although an aversion to the strikeout. Detwiler, with a 92-mph fastball compared to Lannan's 89 mph, could certainly improve in that regard. Regardless, Detwiler finished with a 3.58 ERA last season, his first full season in the majors.

San Francisco Giants

Matt Cain keeps on getting better and better. He threw a perfect game on June 13 and helped lead the Giants to their second championship in three years, which was symbolic of his season overall -- a genuine masterpiece. Cain, in his seventh full season, set a career-high in strikeout rate (22%), and career-lows in walk rate (6%) and ERA (2.79). It marked the third season in the past four in which he finished with a sub-3.00 ERA. One of Cain's unique abilities is inducing weak infield pop-ups. He has had a 10 percent or higher infield pop-up rate in every season and owns the fifth-highest overall pop-up rate (12.3%) dating back to 2006.

Is this the year Madison Bumgarner makes the big leap and becomes a Cy Young contender? Jose Luis Villegas/Getty Images

Madison Bumgarner has quickly evolved into one of of baseball's best lefties after ranking in the top-15 of Baseball America's top 100 prospects in both 2009 and '10. He is one of only two active pitchers (minimum 500 innings) -- the other being Felix Hernandez -- to post a 110 or better adjusted ERA before the age of 23. Perhaps most importantly, Bumgarner has yet to allow a run in two World Series starts (one in 2010, and one in 2012). The lefty signed a five-year, $35 million extension with the Giants last April, keeping him in San Francisco through 2017, potentially 2019 with the two club options at the end of the deal. If Bumgarner can continue to succeed the way he has since moving into the rotation in 2010, that extension will look like an incredible bargain for the Giants.

It is strange to see Tim Lincecum as a No. 3, but after his 2012 showing it makes sense. The two-time Cy Young award winner finished with a 5.18 ERA in 186 innings over 33 starts. He moved to the bullpen for the postseason and finally found some success, allowing one run with a 17-to-2 strikeout-to-walk ratio in 13 relief innings. What was the issue? Lincecum's velocity declined across the board, but most notably with his fastball, down a whopping 2 mph. It is tough to project him going forward, since he is such a unique pitcher having experienced so much success at such a young age. Dan Szymborski's ZiPS projections, though, see him bouncing back to a 3.67 ERA, which would make the Giants very happy.

If any pitcher named in this article can be classified as a hidden gem it is Ryan Vogelsong. Originally a fifth-round draft pick by the Giants in 1998, Vogelsong spent the bulk of his career floundering with the Pittsburgh Pirates, then settling for minor league contracts with the Angels and Phillies before winding up back with the Giants. Vogelsong redeemed himself in a big way, finishing 2011 with a 2.71 ERA and making his first All-Star team. Many remained skeptical, however, so Vogelsong had to prove them wrong again last season, finishing with a 3.37 ERA and emerging as one of the Giants' most reliable postseason contributors, posting a 1.09 ERA in four starts. Now 35 years old, many still wonder when the carriage will turn back into a pumpkin, but for now, Vogelsong and the Giants are enjoying the ride.

Rounding out the rotation is Barry Zito in the last year of his seven-year, $126 million contract. Once thought to be a future Hall of Famer while with the Oakland Athletics, Zito has had tremendous adversity since coming to San Francisco in 2007. Since then, he has a 4.47 ERA in 1,006 innings. In 2002, the year he won his Cy Young award, he struck out 19 percent of hitters. Last season, he struck out 14 percent.

No, he is not close to the pitcher he once was, but if his performance in Game 1 of the 2012 World Series is any indication (5.1 IP, 1 ER), he still has something left in the tank.

With my top five candidates revealed and explained, I would rank them thusly:

1. Detroit Tigers

2. Washington Nationals

3. Philadelphia Phillies

4. San Francisco Giants

5. Tampa Bay Rays

How would you rank baseball's best starting rotations? Vote and let us know in the comments.

Bill Baer is the creator of the Phillies blog Crashburn Alley. You can follow him on Twitter @CrashburnAlley.