The value of starting pitching was never more evident over the winter, when free-agent starters Barry Zito, Ted Lilly, Gil Meche, Jeff Suppan, Daisuke Matsuzaka, Jason Schmidt, Adam Eaton, Kei Igawa, Orlando Hernandez and Jason Marquis signed multiyear contracts worth a combined $490.5 million.

That's nearly half a billion dollars for 10 pitchers, or $11.68 million per year over the duration of the contracts.

Time will tell whether it was money well spent, but an informal polling of various baseball officials asked to rate the best rotations in the game for MLB.com's Best of 2007 series indicated quality depth, fewest health concerns, recent performance and experience were bigger factors in assessing rotations than money.

Depth was especially important. Minnesota's Johan Santana and Chris Carpenter of St. Louis might be the best starters in their respective leagues, but questions about the rotations behind the two Cy Young Award winners kept their teams off the top-five list.

Similar questions hurt Arizona, where 2006 Cy Young Award winner Brandon Webb and workhorses Livan Hernandez and Doug Davis are expected to be joined by 43-year-old Randy Johnson and perhaps Edgar Gonzalez, whose modest resume includes 17-career starts.

The unproven factor eliminated other rotations, which could otherwise prove to be among the best in 2007. Boston shelled out $103 million, including a $51.1 million posting fee, for Matsuzaka, but he's never started a Major League game. Another new Red Sox starter, Jonathan Papelbon, is moving from closer to the rotation.

Igawa's first regular-season start for the Yankees will be the first Major League start of his career, and the New York rotation is also expected to include right-hander Carl Pavano, who has missed the last season and a half with assorted injuries. Those two obvious question marks eliminated the Yankees' rotation from consideration, despite their having a very strong trio of Chien-Ming Wang, Mike Mussina and Andy Pettitte.

Similar situations exist for San Francisco, which has an impressive first three in Zito, Matt Cain and Matt Morris, but has the perception of a significant drop-off after that. And Toronto, with 16-game winner and former Cy Young Award winner Roy Halladay teaming up with A.J. Burnett and Gustavo Chacin, has an excellent starting trio but questions about the level of production from the final two slots -- projected to be Tomo Ohka and John Thomson -- derailed the Blue Jays rotation's chances of cracking the top five.

The Los Angeles Dodgers' trio of Derek Lowe, Schmidt and Brad Penny combined for 43 wins and more than 600 innings last season, but behind those three, there are potential health (Randy Wolf) and youth (Chad Billingsley) questions.

Atlanta (Mike Hampton returns from a two-year absence due to injury), Philadelphia (Eaton's health combined with Brett Myers' and Cole Hamels' youth), Oakland (which lost Zito but should have an outstanding rotation if Rich Harden stays healthy and Joe Kennedy comes through) and Seattle (Horacio Ramirez is the only projected Mariners starter with an ERA under 4.50 last season) have the potential to be among the top five at season's end, but didn't quite make the cut this time.

The Best
MLB.com spends a week exploring which teams are considered the very best in five key categories:
  • Everyday lineup
  • Starting rotation
  • Bullpen
  • Infield
  • Outfield

The rotations that did:

No. 5 -- Chicago White Sox
The White Sox are younger than they were this time last year, and yet they still have four starters who combined for 54 wins, 815 innings and a 4.65 ERA in Jose Contreras, Mark Buehrle, Jon Garland and Javier Vazquez. The question mark is projected fifth starter Gavin Floyd, who has made just 19 career starts and had a 7.29 ERA last season though he possesses an above average arm.

No. 4 -- San Diego Padres
The Padres' rotation led the National League in ERA last year (4.10) and should be even better this time with Greg Maddux (15-14, 4.20 ERA, 210 innings last year) joining Jake Peavy (11-14, 4.09 ERA, 202 1/3), Chris Young (11-5, 3.46 ERA, 179 1/3), Clay Hensley (11-12, 3.71 ERA, 187) and veteran David Wells (3.49 ERA in five starts after coming over from Boston).

No. 3 -- Los Angeles Angels
The Angels' rotation is once again deep and talented even with Bartolo Colon on the mend. Angels starters had the second-best ERA (4.16) of any rotation in the American League last season, gave up fewer homers (109) and held opposing hitters to a lower batting average (.259) than any team in the AL. John Lackey (13-11, 3.56 ERA, 217 2/3), Kelvim Escobar (11-14, 3.61 ERA, 189 1/3), Ervin Santana (16-8, 4.28 ERA, 204) and Jered Weaver (11-2, 2.56 ERA, 123) are all potential 20-game winners. Joe Saunders is expected to handle the other rotation spot until Colon returns.

No. 2 -- Cleveland Indians
Three lefties and two right-handers. Five guys who answer the bell, with the fewest missed starts of any team in baseball last year, and a proven ability to succeed at the Major League level. The Indians have all that in C.C. Sabathia (12-11, 3.22 ERA, 192 2/3), Jake Westbrook (15-10, 4.17 ERA, 211 1/3), Cliff Lee (14-11, 4.40 ERA, 200 2/3), Paul Byrd (10-9, 4.88 ERA, 179) and Jeremy Sowers (7-4, 3.57 ERA in 14 starts last year).

No. 1 -- Detroit Tigers
The Tigers' rotation ERA of 4.00 was the best in baseball last year, and the unit also set the standard in wins (75) and winning percentage (.615). Ace Kenny Rogers (17-8, 3.84 ERA, 204) once again heads up an exceptional rotation that will also include Jeremy Bonderman (14-8, 4.08 ERA, 214), Nate Robertson (13-13, 3.84 ERA, 208 2/3), Mike Maroth (5-2, 4.19 ERA, 53 2/3) and Justin Verlander (17-9, 3.63 ERA, 186).