Ranking MLB's Greatest Rookie Postseason Pitching Performances of All Time

Mike Rosenbaum@GoldenSombreroMLB Prospects Lead WriterOctober 18, 2013

Oct 12, 2013; St. Louis, MO, USA; St. Louis Cardinals fans cheer as starting pitcher Michael Wacha (52) walks back to the dugout for a pitching change against the Los Angeles Dodgers during the 7th inning in game two of the National League Championship Series baseball game at Busch Stadium. Mandatory Credit: Jeff Curry-USA TODAY Sports
Jeff Curry-USA TODAY Sports

If there’s a central theme to the 2013 postseason, it’s that rookie pitchers are excelling in their first taste of playoff baseball. 

Fans have been treated to a glimpse of the game’s increasingly bright future on the mound this October thanks to impressive performances of right-handers Gerrit Cole, Sonny Gray and Michael Wacha.

In fact, Wacha has emerged as the postseason’s most talked about pitcher in the wake of his domination of the Pirates in Game 4 of the NLDS and Dodgers in Game 2 of the NLCS. In the latter contest, the 22-year-old out-dueled Clayton Kershaw and guided St. Louis to a 2-0 series lead with 6.2 scoreless innings. 

On Friday night, Wacha will have a chance to add to his already impressive postseason résumé when he takes the mound in Game 6 in St. Louis. And if his previous starts are signs of what to expect, the right-hander has the potential to be a household name by the morning.

However, Wacha’s overwhelming success in each series got me thinking: what are the best performances by a rookie pitcher in postseason history?

To get to the bottom of it, I turned to Baseball Reference’s highly addictive Play Index Tool, which helped me produce a master list based on age on the date of the game, which was then narrowed to include only rookies. 

In terms of how they were ranked, I ultimately decided that Win Probability Added (WPA) was most effective metric towards measuring a pitcher’s single-game performance, and especially in a best of five- or seven-game postseason series.

So, here’s a look at the 10 greatest rookie pitching performances in playoff history.

Highest WPA By A Rookie Pitcher in a Postseason Game
Livan Hernandez221997FLANLCS Game 59312150.609
Hugh Bedient221912BOSWS Game 5930340.603
Fernando Valenzuela201981LADNLDS Game 4941140.548
Sonny Gray232013OAKALDS Game 2840290.529
Mariano Rivera251995NYYALDS Game 23.120050.471
Paul Dean221934STLWS Game 6971240.471
Madison Bumgarner212010SFGWS Game 4830260.463
John Lackey232002LAAALCS Game 4730070.459
Paul Dean221934STLWS Game 3981570.400
Michael Wacha222013STLNLCS Game 26.250180.389

1. Livan Hernandez, RHP, Florida Marlins (1997)

As I expected before delving into and sorting the results, Livan Hernandez’s complete-game masterpiece against the Braves in Game 5 of the 1997 NLCS ranks as the best performance by a rookie pitcher in a postseason game. Throwing 143 pitches (88 strikes) in the outing, the 22-year-old allowed only five baserunners and piled up 15 strikeouts—the most of any pitcher on this list. Hernandez’s historic performance in Game 5, as well as an outstanding showing out of the bullpen in Game 3, resulted in NLCS MVP honors, while the Marlins went on to win its first World Series in franchise history.

2. Hugh Bediant, RHP, Boston Red Sox (1912)

Because I’m neither a baseball historian nor over 111 years old, I can’t offer any insight into Hugh Bedient’s Game 5 gem in the 1912 World Series. However, we do know that the right-hander served as Boston’s ace during the eight-game series—Game 2 was played to a 6-6 tie—posting a 0.50 ERA in 18 innings spanning four appearances (two starts).

3. Fernando Valenzuela, LHP, Los Angeles Dodgers (1981)

1981 will always be remembered as the year of Fernandomania.

After debuting in the major leagues at the end of the 1980 season, Valenzuela, 20, took the sporting world by storm with his performance the following year. Making 20 starts for the Dodgers, the rookie left-hander posted a 2.48 ERA and led all major league pitchers with eight shutouts and 180 strikeouts. As a result of his enormous success, Valenzuela was named as both the NL Rookie of the Year and Cy Young Award winner following the season.

The southpaw’s legend grew to epic proportions during the 1981 postseason when he pitched the Dodgers to their first World Series title since 1965. Though he was solid in each round of the playoffs, Valenzuela’s shining moment was undoubtedly Game 4 of NLDS when he fired a four-hit complete game to tie the series at two games apiece.

4. Sonny Gray, RHP, Oakland Athletics (2013)

Called up from the minor leagues for good in early August, Gray was the A’s hottest pitcher over the final two months of the regular season, posting a 5-3 record and 2.85 ERA with 61 strikeouts in 60 innings. Despite his inexperience at the major-league level, the 23-year-old’s composure and success in the heat of a playoff race gave manager Bob Melvin the confidence to start him in Game 2 of the ALDS against the Tigers. 

With the A’s already behind 1-0 in the series, Gray matched zeroes with Detroit starter Justin Verlander over the course of the game, allowing only four hits and two walks with nine strikeouts in eight scoreless innings.

5. Mariano Rivera, RHP, New York Yankees (1995)

It’s only appropriate that the lone reliever to make this list is none other than Mariano Rivera.

After debuting with the Yankees in late May, Rivera appeared in only 19 games (10 starts) during the regular season as he bounced between the bullpen and starting rotation. Basically, the organization knew they had something special in Rivera but, at that time, wasn’t sure what that was exactly.

Well, the 25-year-old answered any questions about his future role with his lights-out performance out of the bullpen in Game 2 of the 1995 ALDS against Seattle. Entering in the 12th inning with the game tied 5-5, Rivera allowed only two hits with five strikeouts over 3.1 scoreless innings and picked up the win after Jim Leyritz hit a walk-off home run in the bottom of the

6 & 9. Paul Dean, RHP, St. Louis Cardinals (1934)

In addition to being the only pitcher from the Live Ball Era (1920-1941), Paul “Daffy” Dean is also the only player to appear twice on this list. Though he didn’t have a Hall of Fame career like his brother, Dizzy Dean, who was also a teammate on the Cardinals, Paul turned in an outstanding rookie season in 1934 with a 3.43 ERA and 16 complete games.

During the World Series later that year, the 22-year-old rookie posted a 2-0 record courtesy of back-to-back complete games for the Cardinals in Games 3 and 6. While he had a solid sophomore campaign in 1935, Dean’s career steadily deteriorated as he logged only 284.1 innings over parts of the next seven seasons.

7. Madison Bumgarner, LHP, San Francisco Giants (2010)

After opening the 2010 season in the minor leagues, Bumgarner was called up to join the Giants’ starting rotation in late June and went on to register a 3.00 ERA in 18 starts during the regular season. While the 20-year-old left-hander pitched well in both the NLDS and NLCS that year, he put himself on the map as one of baseball’s best young pitchers with his Game 4 start in the World Series against the Texas Rangers.

With the Giants already up 2-1 in the best-of-seven series, Bumgarner fired eight scoreless innings in which he allowed three hits and two walks with six strikeouts. More importantly, San Francisco won the game, 4-0, and went on to defeat the Rangers the following night in Game 5 to win the 2010 World Series. 

8. John Lackey, RHP, Los Angeles Angels (2003)

Called up to the major leagues in late June of the 2002 season, Lackey solidified the back end of an already solid Angels starting rotation by posting a 3.66 ERA and nine wins in 18 starts. Meanwhile, the 23-year-old’s consistency and knack for excelling in big games helped the Angels win the AL Wild Card and secure a spot in the postseason.

After working out of the bullpen in the best-of-five ALDS, Lackey was moved into the starting rotation for the LCS against the Twins. Making his first career postseason start in Game 4 with the Angels leading the series 2-1, the rookie right-hander allowed three hits with seven strikeouts over seven scoreless innings and needed only 79 pitches (55 strikes) to complete the outing.

10. Michael Wacha, RHP, St. Louis Cardinals (2013)

Inserted into the Cardinals’ starting rotation in early September, Wacha was 2-1 with a 1.72 ERA, .198 opponent batting average and 28/10 strikeout-to-walk ratio in 31.1 innings (five starts) over the final month of the season. As a result of his overwhelming late-season success, the 22-year-old was named to the team’s playoff rotation.

Facing elimination with a loss to the Pirates in Game 4 of the NLDS, Wacha was highly impressive in his postseason as he allowed one run on one hit and two walks with nine strikeouts over 7.1 impressive frames. The right-hander carried a no-hit bid into the eighth inning before surrendering a solo home run to Pedro Alvarez with one out.

Amazingly, it wasn’t that start that earned him a spot on this list.

Moved up in the rotation to start Game 2 of the NLCS against the Los Angeles Dodgers, Wacha captured the nation’s attention as he out-dueled soon-to-be two-time Cy Young Award winner Clayton Kershaw and gave the Cardinals an early 2-0 lead in the series. Even though Wacha’s 6.2 innings in the outing represents the shortest start among pitchers on this list, his being removed from the game was the result of a high pitch count (112 pitches). It obviously had nothing to do with his performance; the right-hander allowed five hits and a walk in the contest while fanning eight batters. 


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