Latest research shows managers inefficient when taking pitchers out of the game

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Peter Dizikes of the MIT News Office highlights one of the finalists in the MIT Sloan Sports Analytics Conference, currently being held in Boston. The paper, “A Data-driven Method for In-game Decision Making in MLB”, was developed by John Guttag and Ganeshapillai Gartheeban.

Guttag and Gartheeban’s developed a model that suggested when managers should take their starting pitchers out of the game by using data from the first 80 percent of the 2006-10 seasons to develop a model. Then they tested their model against the results in the final 20 percent of the season.

Dizikes summarizes some of the important findings:

The study finds that from the fifth inning on, in close games, pitchers who were left in games when the model recommended replacing them allowed runs 60 percent of the time, compared to 43 percent of the time overall.

[…]

Over 21,538 innings, the Guttag-Gartheeban model disagreed with the manager’s decision regarding his starting pitcher 48 percent of the time. About 43 percent of the time, the manager left the starting pitcher in when the model indicated he should be replaced. In just 5 percent of the cases did managers pull starting pitchers when the model suggested they should stay in the game

Guttag and Gartheeban do note that their methodology doesn’t consider every factor and recognize that the manager is considering a lot more than just the current game situation. Hypothetically, leaving Justin Verlander in with a 110 pitch count in a 2-1 game in the bottom of the eighth in late September when the Tigers are only in the lead by a game could be justifiable when most objective models would suggest taking him out.

That being said, many managers can improve simply by not having their pitchers throw unnecessary innings, like the seventh inning after their team has taken a 10-1 lead.

Report: Pirates sign Felipe Rivero to four-year contract extension

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Ken Rosenthal of The Athletic reports that the Pirates will sign reliever Felipe Rivero to a four-year contract extension that includes two club options. The total value of the deal is believed to be $22 million and each club option is worth $10 million.

Rivero, 26, did not come to an agreement with the Pirates to avoid arbitration in his first year of eligibility ahead of last Friday’s deadline. He requested a $2.9 million salary for the 2018 season while the Pirates countered at $2.4 million. This extension will cover all four years of Rivero’s arbitration eligibility and the two club options can cover his first two years of free agency as well.

Rivero was one of baseball’s best relievers last season, finishing with 21 saves, a 1.67 ERA, and an 88/20 K/BB ratio in 75 1/3 innings. The Pirates acquired him from the Nationals along with minor leaguer Taylor Hearn ahead of the 2016 non-waiver trade deadline in the Mark Melancon deal.

Presumably, Rivero’s extension was in the works before he knew anything about the Andrew McCutchen trade. He made a couple of tweets following this afternoon’s news. In one, he used only the “facepalm” emoji. The other was a .gif of The Office character Jim Halpert yelling, “What is going on?”