I made a list, using Win Shares, of major league starters with 10 or more Win Shares last year, then tracked down their origins. I apologize for the bad formatting; I'm not using my normal computer today and am having some problems.

Tim Lincecum, RHP, Giants   27 WS        1^st round, 2006, University of Washington
C.C. Sabathia, LHP, Brewers        25 WS     1^st round, 1998, California HS
Cliff Lee,LHP, Indians            25 WS        4^th round, 2000, University of Arkansas
Roy Halladay, RHP, Blue Jays    23 WS    1^st round, 1995,  Colorado HS
Brandon Webb, RHP, D-backs    22 WS    8^th round, 2000, University of Kentucky
Johan Santana, LHP, Mets           21  WS    Free Agent, 1995, Venezuela
Dan Haren, RHP, D-backs        20 WS       2^nd round, 2001, Pepperdine
Ervin Santana, RHP, Angels     19 WS       Free Agent, 2001, Dominican Republic
Jon Lester,LHP, Red Sox          19 WS       2^nd round, 2002, Washington HS
Joe Saunders, LHP, Angels       19 WS       1^st round, 2002, Virginia Tech
Cole Hamels, LHP, Phillies       19 WS      1^st round, 2002, California HS
Mike Mussina,RHP,Yankees     18 WS      1^st round, 1990, Stanford University
Ryan Dempster, RHP, Cubs      18 WS       3^rd round, 1995, British Columbia HS
Roy Oswalt, RHP, Astros          18 WS       23^rd round, 1996, Holmes CC
Aaron Cook, RHP, Rockies       17 WS       2^nd round, 1997, Ohio HS
Diasuke Matsuzaka, RHP, Red Sox 17 WS   Free agent, 2007, Japan
Edinson Volquez, RHP, Reds       17 WS       Free agent, 2001, Dominican Republic
John Danks,LHP, White Sox       17 WS       1^st round, 2003, Texas HS
Zack Greinke, RHP,Royals          17 WS       1^st round, 2002, Florida HS
Ben Sheets, RHP, Brewers           16 WS       1^st round, 1999, Louisiana-Monroe
Chad Billingsley,RHP, Dodgers   16 WS       1^st round, 2003, Ohio HS
Carlos Zambrano, RHP, Cubs       16 WS       Free agent, 1997, Venezuela
Derek Lowe, RHP, Dodgers         16 WS        8^th round, 1991, Michigan HS
James Shields, RHP, Rays            16 WS        16^th round, 2000, California HS
Mark Buehrle, LHP, White Sox    16 WS       38^th round, 1999, Jefferson JC
Ricky Nolasco, RHP, Marlins       16 WS         4^th round, 2001, California HS
Felix Hernandez, RHP, Mariners   15 WS        Free agent, 2002, Venezuela
Gavin Floyd,RHP, White Sox        15 WS        1^st round, 2001, Maryland HS 
Gil Meche, RHP, Royals                15 WS        1^st round, 1995, Louisiana HS
Jake Peavy, RHP, Padres                15 WS       15^th round, 1999, Alabama HS
A.J. Burnett, RHP, Blue Jays          14 WS        8^th round, 1995, Arkansas HS
Armando Galarraga, RHP, Tigers   14 WS        Free agent, 1998, Venezuela
Justin Duchscherer, RHP,Athletics  14 WS       8^th round, 1996, Texas HS
Jeremy Guthrie, RHP, Orioles         14 WS        1^st round, 2002, Stanford
Matt Cain,RHP, Giants                    14 WS        1^st round, 2002, Tennessee HS
John Lackey, RHP, Angels              14 WS        2^nd round, 1999, Grayson County CC
Jesse Litsch, RHP, Blue Jays           13 WS       24^th round, 2004, South Florida CC
Jamie Moyer, LHP, Phillies             13 WS         6^th round, 1984, St. Joseph's
Kyle Lohse, RHP, Cards                   13 WS        29^th round, 1996, California JC
Matt Garza, RHP, Rays                    13 WS         1^st round, 2005, Fresno State
Scott Baker, RHP, Twins                 13 WS       2^nd round, 2003, Oklahoma State
Ted Lilly, LHP, Cubs                       13 WS       23^rd round, 1996, Fresno CC
Todd Wellemeyer, RHP, Cardinals  13 WS       4^th round, 2000, Bellarmine
Adam Wainwright, RHP, Cardinals  12 WS      1^st round, 2000, Georgia HS
Jair Jurrjens, RHP, Braves                 12 WS       Free agent, 2003, Curacao
Mike Pelfrey, RHP, Mets                   12 WS      1^st round, 2005, Wichita State
Paul Maholm, LHP, Pirates                12 WS      1^st round, 2003 ,Mississippi State
Randy Johnson, LHP, Dbacks            12 WS      2^nd round, 1985, Southern Cal
Scott Kazmir, LHP, Rays                   12 WS      1^st round, 2002, Texas HS
Shaun Marcum, RHP, Blue Jays        12 WS      3^rd round, 2003, SW Missouri State
Andy Pettitte,LHP, Yankees              11 WS      22^nd round, 1990, San Jacinto JC
Braden Looper, RHP, Cardinals        11 WS       1^st round, 1996, Wichita State
Josh Beckett, RHP, Red Sox             11 WS        1^st round, 1999, Texas HS
Javier Vazquez, RHP, White Sox      11 WS        5^th round, 1994, Puerto Rico HS
Jered Weaver, RHP, Angels               11 WS        1^st round, 2004, Long Beach State
Tim Hudson, RHP, Braves                 11 WS        6^th round, 1997, Auburn
Tim Wakefield, RHP, Red Sox          11 WS         8^th round, 1988, Florida Tech
Ubaldo Jimenez, RHP, Rockies         11 WS         Free agent, 2001, Dominican
Andy Sonnanstine, RHP, Rays          10 WS          13^th round, 2004, Kent State
Bronson Arroyo, RHP, Reds             10  WS         3^rd round, 1995, Florida HS
Edwin Jackson, RHP, Rays               10 WS           6^th round, 2001, Georgia HS
Greg Smith, LHP, Athletics               10 WS          6^th round, 2005, Louisiana State
Hiroki Kuroda, LHP, Dodgers           10 WS          Free agent, 2008, Japan
Kevin Slowey, RHP, Twins               10 WS          2^nd round, 2005, Winthrop
Nick Blackburn, RHP, Twins            10 WS          29^th round, 2001, Seminole JC

65 Starters Total

22 First Round Picks                34%
7 Second Round Picks              11%
7 Third to Fifth Round Picks    11%
9 Sixth to 10^th Round Picks      14%
10 11^th round or later Picks       15%
10  Free Agents                         15%

24 High School Pitchers               37%
8   Junior College Pitchers            12%
23  Four-Year College Pitchers     35%
8   Latin American Free Agents    12%
2   Japanese Free Agents                4%

High School Origins: California 4; Texas 4; Florida 2; Georgia 2; Ohio 2; Alabama, Arkansas,Canada, Colorado,Louisiana, Maryland,Michigan,Puerto Rico, Tennessee, Washington, 1 each.

We will look at closer origins next, then draw some conclusions.