From SABR member Rob Mains at Baseball Prospectus on October 16, 2019:
The term quality start is credited to Philadelphia Inquirer sportswriter John Lowe. It’s been derided ever since he coined it in December 1985. This is a typical opinion, from early this season:
As an aside, the quality start metric is poor, especially in this day and age. To qualify, a pitcher need only hold the opposing offense to three or fewer runs over six or more innings. Similarly stated: a 4.50 ERA at minimum. A 4.50 ERA is what one might expect from a No. 4 starter, so it is not exactly indicative of a “quality” pitching performance.
Bill Baer, “Twins end Jacob deGrom’s quality start streak at 26,” Hardball Talk, April 9, 2019
No. No, no, no, no, no.
First, while Baer didn’t know it at the time, a 4.50 ERA in 2019 wasn’t that bad. The American League ERA was 4.60. The NL’s was 4.38. There were 146 pitchers who started at least 15 games last year. That’s close to five per team. Only 90, a little over three in five, had an ERA of 4.50 or lower. That’s not No. 4 starter territory. Here are some pitchers with an ERA over 4.50: Jake Arrieta (4.64), German Márquez (4.76), Dylan Bundy (4.79), José Quintana (4.80). Do any of those strike you as no. 4 starters?
Read the full article here: https://www.baseballprospectus.com/news/article/54521/flu-like-symptoms-the-state-of-the-quality-start-in-2019/
Originally published: October 17, 2019. Last Updated: October 17, 2019.