In 1884, Charlie "Old Hoss" Radbourn started 73 of his team's 112 games. In these games, Old Hoss went 59-12, setting an all-time record for pitching victories.
He also led the league with a 1.38 ERA and 207 ERA+. He was as effective as Sandy Koufax in his prime, pitching 2-3 times as many innings.
By the end of the season, Old Hoss couldn't raise his arm over his head. He couldn't dress himself every morning. That responsibility fell to his roommate, and manager, Frank Bancroft. Pitching through excruciating pain, he led the Providence Grays to a National League tittle.
Radbourn's 1884 season takes the cake as the greatest season any pitcher has ever had. But the game was different back then. Since 1900, baseball's modern era, no pitcher has approached Radbourn's 59 wins.
Even so, the game has seen it's share of dominant pitching seasons, from a 20-year-old phenom who took baseball by storm in the 1980s, to a pair of 34-year-old 300-game winners proving they were far from finished.
No pitcher will appear on this list more than once. A few could have, but I limited it to one season per pitcher.
Following the 1996 season season, Roger Clemens, whose 192 wins tie Cy Young for most in Red Sox history, declined to re-sign with the team he'd spent his first 13 seasons with.
The three-time Cy Young award winner had a career record of 192-111, and was coming off a season in which he led the American League in strikeouts, finishing seventh in ERA.
But Red Sox GM Dan Duquette felt as though Clemens was in the twilight of his career, and allowed his star pitcher to sign a four-year, $40 million contract with the Toronto Blue Jays.
Clemens stared off the 1997 season in style. In his first game versus the Chicago White Sox, Clemens pitched all 9 innings, allowing just 1 run, and striking out 9 batters. Despite a poor start against Seattle on April 25, Clemens finished the month of April with a 1.72 ERA.
From April 19 to July 28, Clemens strung together 20 starts of at least seven innings. In 16 of those starts, he allowed two or fewer runs. He struck out 10 or more batters eight times.
On July 12th, pitching against his former team for the first time, in Fenway Park, he pitched 8 innings, allowing 1 run and striking out 16 batters. He gave up just 4 hits, and didn't walk a batter.
By the end of July, the Blue Jays had fallen out of the AL East race. Clemens however was 16-6, with a 1.52 ERA and 183 strikeouts, a near lock to win the Cy Young award for the fourth time in his career.
Down the stretch, Clemens pitched four more complete games, struck out 10+ batters six more times, and finished with an ERA of just 2.05.
When it was all said and done, Clemens led the league in innings, ERA, wins, complete games, shutouts, strikeouts, and WHIP, giving him the pitching Triple Crown.
He nearly unanimously won the Cy Young award, receiving 25 of 28 votes. Clemens won his fifth Cy Young award the following season, again winning the Triple Crown, with 20 wins, 271 strikeouts, and a 2.65 ERA.
For 11 years, from 1890 to 1900, Cy Young dominated National League batters, winning 30 games three times. Still, in 1900, Young looked on the downside of his career.
At 33, he had lost as many games as he had won. His 3.00 ERA ranked just eight in the American League. He was still one of the game's biggest stars, but no longer seemed the best pitcher in baseball.
In 1901, Ban Johnson's American League officially declared itself a "Major League," the equal of the National League. Johnson lured over a hundred National Leaguers, including Young and the game's best hitter, Napoleon Lajoie.
Young joined the Boston Americans, and went on to post one of baseball's best seasons. In 41 starts, Young completed 38, throwing 5 shutouts. He led the league with 33 games on a Red Sox team that won 79, and ERA with 1.62 mark.
He also led the league with 158 strikeouts, giving him the American League Triple Crown.
The Red Sox finished second to Chicago that season. Young would lead the American League in wins in its first three seasons, and in 1903, lead the Red Sox to victory in the first ever World Series over Honus Wagner's Pittsburgh Pirates.
In April 1966, with the baseball season looming, Dodgers team doctor Peter Karlen told Sandy Koufax that his arm could not handle another season.
A year earlier, Koufax had awoken to find his left arm black and blue. Despite winning the 1965 Cy Young award, Karlen wanted Koufax to retire. Instead, Koufax had what was probably his greatest season.
Koufax began the season with a couple of short starts, but completed 14 of his next 16 games. At the All Star break, Koufax had 1.60 ERA and 165 strikeouts. He started the All Star game, and was the winning pitcher, giving up a run in three innings.
On July 27, against the Phillies, Koufax pitched perhaps his best game of the season. In 11 innings, Koufax gave up four hits and a run, striking out 16 batters.
He was finally relieved in the top of the 12th inning, and in the bottom of the inning, the Dodgers finally scored their second run.
Koufax's game reached another level down the stretch. He completed five of his final six starts, allowing 2 or fewer runs in each. The Dodgers won the pennant by a single game.
Coming off a 1965 season in which he set the modern baseball record for strikeouts, Koufax one-upped himself. Though he struck out fewer batters, he led the league with 317, and also led the league with a 1.73 ERA and 27 wins, winning baseball's Triple Crown, and his third unanimous Cy Young Award in four seasons.
The Dodgers were swept in the World Series that season. Following the loss, Koufax called a press conference, announcing his retirement at the age of 30.
Steve Carlton, entering 1972, did not have a future Hall of Fame resume. He had been a good pitcher for several seasons, made 3 All Star games, and was coming off his first career 20 win season.
But he had also led the league in losses in 1970, and had only struck out 200 batters once in his career. His 1972 season was the picture of dominance.
Steve Carlton was the National League's best pitcher in the first half of the '72 season. He won 14 games with a 2.48 ERA and struck out 201 batters.
He made his fourth All-Star game. Bob Gibson started the game, but his ERA was a bit higher, he won fewer games, and he struck out 90 fewer batters.
Carlton pulled away in the second half. Though his team lost nearly 100 games that season, Carlton won 13 after the All-Star break, losing just 4. His ERA was a minuscule 1.32, and he completed 15 of his 17 starts.
Though his strikeout numbers dropped off a bit, Carlton allowed fewer than a baserunner an inning.
At the end of the season, pitching for a horrible Phillies team, Carlton had a record of 27-10. He led the league in wins, with six more than second place Tom Seaver.
He also led the league in ERA at 1.97, and in innings, with 346, 57 more than second place Fergie Jenkins. He led the league in strikeouts with 310, 61 more than second place Seaver, and in complete games with 30, seven more than the next highest finisher.
He won the Cy Young unanimously with 24 first-place votes.
Baseball's biggest phenom, Dwight Gooden, was the fifth overall pick in the 1982 MLB draft, selected by the New York Mets out of a Florida high school.
After a 1983 season in which he struck out 300 batters in 191 innings, Gooden jumped to the Majors for his second pro season.
In 1984, Gooden led the league with 276 strikeouts, finished second with a 2.60 ERA, and nearly won the Cy Young as a rookie, finishing second to Rick Sutcliffe. Dwight didn't have to settle for second best in 1985.
During the '85 season, Doc went 24-4, to lead the league in wins. In his four losses, Gooden struck out a batter an inning and posted a 2.89 ERA.
Dwight's 1.53 ERA was 129% better than the league average, and 40 points lower than anyone else in the National League.
Dwight completed 16 of his 35 starts, and shutout his opponent on eight occasions. He led the league with 276.2 innings pitched, and allowed fewer than a base runner per inning.
At the end of the season, Gooden won an unanimous Cy Young award, with 24 of 24 first place votes. The Mets won 98 games, and fished second in the NL East.
The following season, at 21, Gooden would again finish in the top-5 in wins, ERA, and strikeouts, leading the Mets to their second World Series Championship.
Greg Maddux is one of the greatest pitchers of all time, finishing his career with over 350 victories and an ERA+ of 132. It's amazing that Maddux's best two seasons were interrupted by the 1994 strike.
It is reasonable to debate whether Maddux's 1994 or 1995 season is better. Maddux had a better ERA in 1994, and pitched about as many innings both years. But his 8.8 Wins Above Replacement in 1995 ranks as the most of his career.
Going into the 1995 season, Maddux was easily baseballs best pitcher. Coming off three straight Cy Young awards, Maddux was a control artist, the smartest pitcher in the game, and also the most durable, leading the league in innings four straight seasons from 1991 to 1994.
The '94 season ended early due to the strike, and the '95 season started late. Maddux's first start was April 26, but he still finished the season with over 200 innings, leading the league with 209.1.
Maddux made 28 starts that season, completing 10. He won 19 games and lost just 2, for a .905 W%, by far the leagues best.
Though Maddux was not known as a strikeout pitcher, he finished third in the league with 181. He walked just 23 batters, giving him a league leading 7.87 K/BB ratio.
His 1.63 ERA was 162 percent better than the league average, and 91 points better than the second place finisher, Hideo Nomo.
Maddux led the Braves to a division championship that year, and in the playoffs, went 4-1, leading the team to a World Series title. He won his fourth straight Cy Young award, capturing all 28 first-place votes.
In my opinion, Lefty Grove is probably the second greatest pitcher who ever lived. In 1926, 1929, and 1930, Grove led the American League in ERA. In fact, he did this nine times.
But it was his 1931 season that would go down as one of the greatest of all time.
Grove was the star pitcher of the Philadelphia Athletics, the 1930 American League Champions. Led by Hall of Famers Jimmie Foxx, Mickey Cochrane, and Al Simmons on offense, and Lefty Grove on the mound, the team was nearly unstoppable.
Grove won the pitching triple crown that year, leading the league for the sixth straight season with 175 strikeouts, and in ERA for the fourth time with an incredible 2.06 mark, 122 percent better than the league average and 61 points better than anyone else.
He won 31 games, losing only four, and completed 27 of 30 starts. He also pitched 11 times in relief, finishing 10 games.
The Athletics won the American League pennant again in 1931. Lefy Grove won the first game of the series, striking out seven batters in nine innings, and allowing just two runs.
After losing game three, he came back to pitch another complete game to win game six. The A's eventually lost to the Cardinals in seven games.
1968 may have been "the year of the pitcher" but no pitcher approached what Bob Gibson did that season.
Gibson had a strange career path, struggling in his first several Major League seasons before becoming one of baseball's all time greats.
Gibson was one of the most intimidating pitchers in the National League, throwing harder than anyone else, and nearly falling over as he followed through on his pitches. He also won nine Gold Gloves.
In 1968, Gibson was unhittable. He completed 28 of 34 starts, pitching 304.2 innings, third in the National League, and won 22 games, second in the league, though Juan Marichal and Fergie Jenkins started 38 and 40 games respectively.
What jumps out about his season is his 1.12 ERA, 158% better than the league average, even in the great year of the pitcher, and 87 points better than the next best finisher.
He saved his team 60 runs, more than double Tom Seaver, who finished second in the National League. He was also credited with 11.9 Wins Above Replacement, 4.4 more than Seaver, who again finished second.
The Cardinals won the 1967 pennant, and Gibson put together a legendary World Series performance. He completed, and won, each of his three starts, allowing just three runs in 27 innings.
His 10 K performance in Game Seven clinched the World Series for St. Louis.
The greatest pitcher in baseball history, Walter Johnson had several seasons that could have appeared on this list.
I chose 1913 as his best, but 1912 was also one of the greatest seasons a pitcher has ever had, as were 1915, 1918, and 1919.
Coming off a season where he led the league in ERA, and won 33 games, it was tough to argue that Johnson was baseball's best pitcher. Many in the media still considered the beloved Christy Mathewson the best in the game, but after 1913, it would be pretty difficult to take that stance.
Johnson led the league with 346 innings pitched. He also won 36 games, losing just 7, for a winning percentage of .837, the best in baseball. He led the league with a 1.14 ERA and 259 ERA+, and also with an incredible 0.780 WHIP.
He allowed just six hits, and one walk, per nine innings pitched. He also led the league with 243 strikeouts, and 11 shutouts, completing 29 of his 36 starts...also leading the league.
He led the league in both strikeout rate and walk rate, and won the MVP award over Shoeless Joe Jackson.
Johnson set several modern baseball records that season, among them wins with 36, and WAR, as he was credited with 12.4 on the mound.
Johnson led the league in wins four of the next five seasons, won another MVP award, and is widely considered the greatest pitcher in the history of the game.
Finally, we're here at No. 1. Pedro Martinez's 2000 season, at the height of baseball's second greatest offensive era, is in my opinion, the greatest pitching season of all time.
Pedro had already been the best pitcher in baseball for a few years. He won the NL Cy Young award in 1997, and after a trade to the Boston Red Sox, won the AL Cy Young award in 1999.
In fact, it could be argued that Pedro's 1999 season was the better year. That just shows how great Pedro was over those two seasons.
Pedro's 2000 statistics are incredible. In 217 innings, Martinez struck out 284, walking just 32. His 0.737 WHIP was the lowest in Major League history.
He allowed just 128 hits that year, becoming the first pitcher the history of Major League Baseball to have more than twice as many strikeouts as hits.
He also set the modern Major League record with 5.3 hits allowed per nine innings. Pedro did all this in 2000, one of the five greatest offensive seasons in the history of the game.
Pedro's 2000 ERA of 1.74 was 191 percent better than the league average, setting a Major League record. The American League average ERA in 2000 was nearly 5.00, and the American League's second best ERA in 2000 was 3.70, and belonging to Roger Clemens, and more than twice Pedro's ERA.
He also set the Major League record for adjusted pitching runs, saving his team 79 runs on the mounds. In 217 innings, Pedro saved his team more runs than Walter Johnson, or Bob Gibson, or Sandy Koufax did in well over 300.
Although Martinez won just 18 games, he did so in 29 starts. In his 6 losses, his ERA was 2.44, still almost 130 points better than the second best ERA in the American League.
Even having lived through this season, it's almost impossible to comprehend. Pedro was literally twice as good as the next best pitcher in his league.
Pedro won the Cy Young unanimously, finishing in the top-4 three of the next four seasons. Martinez has the best career ERA in Major League history relative to the league.