Ranking the greatest pitchers in baseball history: Nos. 20-1

Throughout the months of January and February, a cast of editors from theScore will share their rankings of the greatest teams, performances, pitchers, and position players in baseball history. This list focuses on the greatest pitchers:

100-81 | 80-61 | 60-41 | 40-21 | 20-1

Voter list:

• James Bisson, National Sports Editor
• Brandon Wile, Senior MLB Editor
• Jonah Birenbaum, MLB News Editor
• Michael Bradburn, MLB News Editor
• Jason Wilson, MLB News Editor
• Bryan Mcwilliam, MLB News Editor
• Simon Sharkey-Gotlieb, MLB News Editor
• Dylan Perego, News Editor
• Josh Wegman, News Editor

20. Roy Halladay

Brandon McCarthy described Halladay the best following his tragic death in November: "Roy Halladay was your favorite player's favorite player. A true ace and a wonderful person." The right-hander was among the elite in his pitching fraternity; an eight-time All-Star and one of six pitchers in history to win a Cy Young in both leagues. The accolades don't stop there, as he was the 20th pitcher to ever throw a perfect game, and just the second to ever toss a no-hitter in the postseason. Amazingly, those accomplishments came just months apart. -- Wile

19. John Smoltz

Smoltz was a chief member of a Braves dynasty that included Greg Maddux and Tom Glavine yet somehow only won one World Series championship. Three seasons after winning the Cy Young as a 29-year-old, Smoltz underwent Tommy John surgery and missed the entire 2000 campaign. When he came back, he spent the next four years as a closer and collected 154 saves, even leading the league in 2002, making him the only pitcher in history with at least 200 wins and 150 saves. -- Bradburn

18. Curt Schilling

Nothing Schilling says or does in his post-playing career can change what he accomplished on the mound - and he accomplished plenty, finishing top-four in Cy Young voting four times while posting a pair of 300-strikeout seasons and making six All-Star teams. And even if you don't buy the "Bloody Sock" narrative from Boston's incredible 2004 title run, you can't deny that Schilling was one of the best pitchers of his - or any - era. -- Bisson

17. Bert Blyleven

"Criminally underappreciated" may be the most apt way to describe Blyleven's career, during which he consistently dominated while failing to get recognized by fans (he was an All-Star just twice) or the BBWAA (he never finished higher than third in Cy Young voting) - a possible consequence of playing so many years in Minnesota. In 1973, for example, Blyleven led the AL in both WAR (10.8) and ERA+ (156), having crafted a 2.52 ERA with 20 wins over 325 innings. Regardless, he finished seventh in Cy Young voting. -- Birenbaum

16. Gaylord Perry

A big part of Perry's legacy may revolve around his notorious use of the spitball, but the right-hander should also be remembered as one of the most consistently effective hurlers in history. Over the course of his stellar 22-year career, Perry eclipsed both the 300-win mark (314) and the 3,000-strikeout mark (3,534). He's also one of just six pitchers to capture a Cy Young Award in both the American League (Cleveland Indians, 1972) and National League (San Diego Padres, 1978). - Perego

15. Warren Spahn

No left-hander in the history of baseball has won more big-league games than Spahn, who accumulated 363 during an impressive 21-year career despite three years of military service in the 1940s. Spahn won 20-plus games 13 times, threw more than 5,000 innings, and finessed his way through a career that only included a strikeout rate of 4.4 per nine (though he still led the NL in strikeouts four times). -- Mcwilliam

14. Lefty Grove

Robert Moses Grove won nine ERA titles, more than any other pitcher in history. He was the ace of Connie Mack's second Philadelphia Athletics dynasty, leading the A's to three straight pennants and a pair of World Series titles from 1929-31. He won the pitching triple crown in both 1930 and '31, while the latter campaign also saw him win 31 games and the AL MVP. Grove captured the league's strikeout title in each of his first seven seasons, and his 109.9 bWAR is the highest-ever total for a left-hander. That's how you earn the nickname, "Lefty." -- Sharkey-Gotlieb

13. Clayton Kershaw

Kershaw's only been in the majors since 2008, but he's building a resume that will place him among the titans of baseball lore. Heck, he's already there. And after 2010, it's like he just decided he wasn't going to walk hitters anymore, issuing less than two free passes per nine innings in every season since. Kershaw is the best pitcher of his generation, and he's only just about to turn 30. Barring injury, he'll go down as the greatest Dodgers pitcher of all time. -- Wilson

12. Bob Gibson

Luckily for baseball, Gibson gave up his brief stint with the Harlem Globetrotters to pitch for the Cardinals, and the intimidating right-hander went on to be one of the greatest pitchers in history. Gibson won 20 games in five different seasons, claimed two Cy Young Awards, and was the 1968 NL MVP. He was the second pitcher to ever amass 3,000 strikeouts and was the first to strike out 200 in a single season. He was at his best in the playoffs, though, where he authored a 1.89 ERA over nine starts, winning two World Series MVP awards. -- Wile

11. Christy Mathewson

Elected to the Hall of Fame in its inaugural class, Mathewson won the pitching triple crown twice during his 17-year career as one of seven pitchers to ever lead the league in wins, ERA, and strikeouts more than once. Famously never pitching on Sundays - refusing to work on the Sabbath - Mathewson later stepped away from baseball following the 1916 season and served in World War I in 1918. Exposed to gas during a training exercise, he developed tuberculosis, which led to his death seven years later. -- Bradburn

10. Sandy Koufax

Imagine Kershaw dominating hitters next season en route to yet another Cy Young Award ... and then abruptly calling it quits. Dodgers fans wouldn't be able to take that happening again; not after watching Koufax leave the sport at his absolute pinnacle. The scintillating lefty won three Cy Young Awards in a four-year span, leading the NL in ERA five straight seasons while posting microscopic WHIPs across a six-year stretch. -- Bisson

9. Steve Carlton

His idiosyncrasies may have rubbed some people the wrong way, but "Lefty" was far more bothersome to opposing hitters, riding his nasty slider to four Cy Young Awards, 10 All-Star nods, five strikeout titles, and a Hall of Fame plaque (receiving it with 95.8 percent of the vote in his first year on the ballot, too). Among left-handed hurlers, only Randy Johnson accrued more WAR or racked up more strikeouts than Carlton, who was famously described by Hall of Famer Richie Ashburn as "a craftsman, an artist; he painted a ballgame." -- Birenbaum

8. Tom Seaver

When it comes to accolades, it's hard to find a pitcher more decorated and universally appreciated than Seaver. After bursting onto the scene with the New York Mets and earning Rookie of the Year honors in 1967, Seaver would capture three Cy Young Awards and post five 20-win seasons while stringing together nine consecutive 200-strikeout campaigns from 1968-76. He was inducted into the Hall of Fame in 1992, and held the record for highest voting percentage in history (98.8 percent) until Ken Griffey's induction in 2016. - Perego

7. Nolan Ryan

Twenty-seven years and 5,714 strikeouts summed up the hardest-throwing pitcher of his time, who didn't think twice about going high and inside. Ryan slots in at No. 7 thanks to a lightning bolt for a right arm. Sure, control wasn't really his thing (2,795 career walks), but that's what made him scary. Hitters not knowing where the ball would go created an uneasy feeling when they stepped to the plate against Ryan, whose seven no-hitters makes him the all-time leader. But somehow, Ryan (who appeared in an MLB game in four consecutive decades) never earned a Cy Young. -- Mcwilliam

6. Walter Johnson

Armed with the most powerful fastball of his day, "The Big Train" won an AL-record 417 games and his record 110 shutouts will likely never be broken. His 3,509 strikeouts stood as the gold standard for decades; in fact, he was the only member of the 3,000-Ks club for 50 years. Though he toiled on mediocre Washington Senators clubs for most of his career, Johnson still won two MVPs, three triple crowns, and 12 strikeout titles. When he finally reached the World Series in 1924, Johnson had his defining moment - four shutout innings out of the bullpen in Game 7 that enabled the Senators to win the championship in a 12-inning thriller. Johnson was a member of the Hall of Fame's inaugural class of 1936, and deservedly so. -- Sharkey-Gotlieb

5. Cy Young

He's the namesake for the annual award for the best pitcher in the game, keeping him in the public consciousness for more than a century after his final game. Young was more than the product of his time, too, as he still holds the all-time records for wins, losses, starts, innings, complete games, hits, and earned runs allowed. -- Wilson

4. Randy Johnson

An intimidating presence on the mound due to his 6-foot-10, 225-pound frame and ability to hit 100-mph with his fastball, Johnson is the best left-handed starter in baseball history. "The Big Unit" pitched for 22 seasons, during which he was a five-time Cy Young winner - four of those coming consecutively - a 10-time All-Star, and a 2001 World Series champion. He also threw a perfect game and a no-hitter 14 years apart, ranks second on the all-time strikeouts list, and recorded the fifth-most wins by a left-handed pitcher. -- Wile

3. Greg Maddux

The 1990s were defined by grunge music, Seinfeld, and Maddux on the mound. Over the ten-year span - seven of which he spent leading the Braves to three World Series appearances including one win - Maddux posted a 176-88 record with a 2.54 ERA, 2.77 FIP, and 1.06 WHIP while winning four consecutive Cy Young Awards. Since his retirement, he's become synonymous with the complete-game shutout in which the pitcher throws fewer than 100 pitches - a feat "The Professor" authored 13 times in his illustrious career. -- Bradburn

2. Pedro Martinez

It's hard to quantify just how incredible Martinez was in an era when the ball was leaving the park more frequently than any time in history - but we'll try our best. His 1.74 ERA in 2000 produced an ERA+ of 291, the greatest mark in modern baseball history and second all time to Tim Keefe, who posted a 293 ERA+ in 1880. Pedro won three Cy Young Awards, finished in the top four on four other occasions, and led the majors in ERA five times. He's a deserving runner-up on this list. -- Bisson

1. Roger Clemens

Sandy Koufax, they said, was blessed with the Left Arm of God. Bob Gibson wanted it the most. Nolan Ryan was a freak of nature. And Roger Clemens - the polarizing, decorated, misremembering Texas boy who became the archetype for the modern-day starter - won more Cy Young Awards than all of them. Combined. From his days at San Jacinto College, Clemens was indefatigable in his efforts to extract every last ounce of his potential - before him, pitchers didn't even really lift. That commitment, along with his considerable natural gifts, turned Roger into the "Rocket," a tireless, bat-breaking, strikeout machine who, throughout his 24-year career, accrued more WAR than any pitcher who ever lived, led his league in ERA seven times (and strikeouts five times), and took home seven Cy Young Awards. Were it not for his connections to PED use - and the ensuing legal trouble - Clemens would've had a plaque in Cooperstown years ago. -- Birenbaum

(Photos courtesy: Getty Images)