Quality start

In baseball, a quality start is a statistic for a starting pitcher defined as a game in which the pitcher completes at least six innings and permits no more than three earned runs.

The quality start was developed by sportswriter John Lowe in 1985 while writing for the Philadelphia Inquirer.^[1] The statistic is preferred by sabermetricians to that of winning percentage (the number of wins garnered by a pitcher as a fraction of his total decisions) insofar as it acts independently of some factors beyond a pitcher's control such as fielding errors, blown saves, and poor run support.^{[citation needed]} ESPN.com terms a loss suffered by a pitcher in a quality start as a tough loss and a win earned by a pitcher in a non-quality start a cheap win.^[2]

All-Time

The highest "quality start" percentage for a given season was recorded by Dwight Gooden, who had 33 of them in 35 games in 1985. Bob Gibson was 32-for-34 in 1968.

Since 1950, and through June 2011, the overall leaders by percentage are:

1. Tim Lincecum (101 of 139, 72.7%)
2. Tom Seaver (454 of 647, 70.2%)
3. Adam Wainwright (83 of 119, 69.7%)
4. Mel Stottlemyre (247 of 356, 69.4%)
5. Roy Oswalt (216 of 316, 68.4%)
6. Josh Johnson (77 of 113, 68.1%)
7. Bob Gibson (328 of 482, 68%)
8. Roy Halladay (226 of 338, 66.9%)
9. Felix Hernandez (127 of 190, 66.8%)
10. Randy Johnson (403 of 603, 66.8%)

Criticisms

High ERA

An early criticism of the statistic, made by Moss Klein, writing in The Sporting News, is that a pitcher could conceivably meet the minimum requirements for a quality start and record a 4.50 ERA, seen as undesirable at the time. Bill James addressed this in his 1987 Baseball Abstract, saying the hypothetical example (a pitcher going exactly 6 innings and allowing exactly 3 runs) was extremely rare amongst starts recorded as quality starts, and that he doubted any pitchers had an ERA over 3.20 in their quality starts. This was later confirmed through computer analysis of all quality starts recorded from 1984 to 1991, which found that the average ERA in quality starts during that time period was 1.91.^[3]

That the category is more reliable in the aggregate can be seen with countervailing individual examples, such as the ones listed by Sports Illustrated writer Joe Posnanski in a 2011 piece on the subject:

"In July 2000, Mark Mulder went 6 2/3 innings, gave up 15 hits and nine runs — but only two were earned, so that was a classified as a quality start.

In June 1997, Randy Johnson struck out 19 in a complete game but allowed four runs. That was not a quality start.

In July 1982, Mike Scott allowed seven hits and walked five in six innings, didn’t strike out anybody, gave up seven runs, but only three of those were earned. Quality start.

In April 1974, Gaylord Perry went 15 innings and allowed four runs. Not a quality start."^[4]

Complete games

Another criticism against the statistic is that it is not beneficial for pitchers who pitch many innings per start. If a pitcher allows three earned runs in six innings, he gets a quality start with an ERA of 4.50 for that game. But if a pitcher pitches for nine innings and allows four earned runs, he would have a 4.00 ERA, but would not get a quality start.

Park effects

Like almost every baseball statistic, quality starts are affected by the home park of the player. At the extreme there are "hitters' parks" with some combination of good visibility, short dimensions, little foul territory, hard turf that aids ground balls in getting past infielders, and warm temperatures at high altitudes that inflate batting averages, increase walks, and make home runs easier to hit. Atlanta's Fulton County Stadium was one such place. Coors Field in Denver was an even more extreme hitter's park before its occupant, the Colorado Rockies, installed a humidor to store game balls in what proved a successful attempt to counteract the effects of Denver's dry, high-altitude climate on baseballs. In contrast, a stadium such as the Oakland Coliseum has unusually long distances to the outfield fences, copious foul ground for fielders and catchers to catch foul fly balls, thick grass that slowed ground balls, and generally cool temperatures that create air resistance to any fly ball. Thus pitchers of similar quality for the Oakland A's would tend to have lower-scoring games and more quality starts than those of the Atlanta Braves or the pre-humidor Rockies.

Team effects

Like most pitching statistics, quality starts are affected by the quality of the defense behind the pitcher. A better defense will result in fewer runs scored and a better chance that the pitcher will be credited with a quality start.

References

1. ^ Neyer, Rob (2006-04-13). "Quality start still a good measure of quality". ESPN. http://insider.espn.go.com/mlb/insider/columns/story?columnist=neyer_rob&id=2407313&action=login&appRedirect=http%3a%2f%2finsider.espn.go.com%2fmlb%2finsider%2fcolumns%2fstory%3fcolumnist%3dneyer_rob%26id%3d2407313. 
2. ^ "MLB Statistics Glossary". ESPN. http://sports.espn.go.com/mlb/news/story?page=stats/glossary. Retrieved 2007-04-19. 
3. ^ Smith, David (Spring 1992). "The Quality Start is a Useful Statistic". http://207.56.97.150/articles/qstart.htm. 
4. ^ http://joeposnanski.si.com/2011/07/03/all-you-never-wanted-to-know-quality-starts/#more-7666