The quality start was developed by sportswriter John Lowe in 1985 while writing for the Philadelphia Inquirer. 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.
Nolan Ryan has used the term "High Quality Start" for games where the pitcher goes seven innings or more and allows three earned runs or less.
Since 1950, and through June 2013, the overall leaders by percentage (min. 100 starts):
- Tom Seaver (454 of 647, 70.2%)
- Mel Stottlemyre (247 of 356, 69.4%)
- Adam Wainwright (115 of 167, 68.8%)
- Bob Gibson (328 of 482, 68%)
- Josh Johnson (103 of 152, 67.7%)
- Roy Oswalt (225 of 336, 67%)
- Randy Johnson (403 of 603, 66.8%)
- Jered Weaver (143 of 214, 66.8%)
- Brandon Webb (132 of 198, 66.7%)
- Pedro Martínez (273 of 409, 66.7%)
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.
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. Former pitcher Carl Erskine said "in my day, a quality start was a complete game ... you gave everybody a day's rest."
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 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, did not 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."
Possible new criteria
|This section does not cite any references or sources. (August 2014)|
Due to the reasons listed above, some have proposed a possible change in the criteria for a quality start. One of the proposals include that for every two innings pitched, the starter is allowed to give up one earned run, and as long as he pitches five innings, a quality start would be recorded. This criteria would give Randy Johnson and Gaylord Perry listed in the above examples quality starts. This criteria would still allow a pitcher to have a 4.50 ERA and earn a quality start, but would better represent a quality start.
Dayn Perry of CBS Sports has introduced what he calls the "Dominate Start".  This stat would award a pitcher with a Dominate Start if they go at least eight innings, and give up no more than one run, earned or unearned. This stat means that if a pitcher pitches a complete game and gives up two unearned runs, he would not get a Dominate Start. Perry argues that this stat would better show which pitchers are truly the best in all of baseball.
- Neyer, Rob (2006-04-13). "Quality start still a good measure of quality". ESPN.
- "MLB Statistics Glossary". ESPN. Retrieved 2007-04-19.
- Smith, David (Spring 1992). "The Quality Start is a Useful Statistic".
- Zimniuch, Fran (2010). Fireman: The Evolution of the Closer in Baseball. Chicago: Triumph Books. p. 74. ISBN 978-1-60078-312-8.
- Joe Blogs: All You Never Wanted To Know: Quality Starts