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.

Kenley Jansen’s consecutive saves streak ends at 34

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Dodgers closer Kenley Jansen gave up three runs in the top of the ninth inning during Sunday’s game against the Braves, blowing his first save since August 26 last season. He had converted 34 consecutive saves.

Jansen yielded back-to-back singles to lead off the ninth inning, staked to a 4-1 lead. After getting two outs, Matt Adams hit a three-run home run down the right field line to knot the game at four apiece.

After Sunday’s lackluster performance, Jansen is now 24-for-25 in save chances this season with a 1.49 ERA and a 62/2 K/BB ratio in 42 1/3 innings.

Zach Britton sets American League record with 55th consecutive save

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Orioles closer Zach Britton finished Sunday’s 9-7 victory over the Astros with a scoreless ninth inning, earning his sixth save of the season. He has now earned the save in 55 consecutive opportunities dating back to September 2015, setting a new American League record. Tom Gordon previously held the record with 54 consecutive saves. Eric Gagne holds the major league record at 84.

Britton’s last blown save came on September 20, 2015, then converted two more saves before the end of the regular season. He went 47-for-47 in save chances last season and is six-for-six so far this year.

Along with his six saves, Britton has a 2.65 ERA and a 13/8 K/BB ratio in 17 innings this season. The lefty came off the disabled list earlier this month after missing two months with a strained left forearm.