"A graded stakes race is a thoroughbred horse race in the United States or Canada that meets the criteria of the American Graded Stakes Committee of the Thoroughbred Owners and Breeders Association (TOBA). A specific grade level (I, II, III or listed) is then assigned to the race, based on statistical analysis of the quality of the field in previous years, provided the race meets the minimum purse criteria for the grade in question. Graded stakes races are similar to Group races in Europe but the grading is more dynamic in North America.

The grading system was designed in 1973 and first published in 1974. The original purpose of grading was to identify the most competitive races, which helps make horsemen comparisons of the relative quality of bloodstock for breeding and sales purposes. A high grading can also be used by racetracks to promote the race in question. When determining Eclipse Award winners, racing journalists will consider the number and grade of a horse's stakes wins during the year.

In general, stakes race refers to the stake, or entry fee, owners must pay, which generally forms part of the prize money offered to the top finishers. Not all stakes races are eligible for grading. Notably, races that are restricted to horses bred in a specific state (e.g., the Tiznow Stakes for California-breds) or country (e.g., the races that make up the Canadian Triple Crown, all restricted to Canadian-breds) are excluded, regardless of the purse or quality of field. Conversely, some races that are not technically stakes races (usually invitational races where entry fees are not required by the racetrack) may be eligible for grading if they meet the quality standards.

Criteria

To determine if a race is eligible for grading, the American Graded Stakes Committee uses the following criteria:

• Purse requirement: That the race has a purse of at least $75,000. ($100,000 for Grade III, $200,000 for Grade II, and $300,000 for Grade I.)
• Longevity: That the race has been run for two years under fundamentally the same conditions. (The race's distance for example may be slightly altered, but age and gender conditions may not.)
• Restrictions: That the race may be restricted only in age and gender.
• Drug testing: That post race drug testing is managed by a governmental authority.
Medication: That model rules on androgenic-anabolic steroids and non-steroidal anti-inflammatory drugs be followed. Specifically, only Boldenone, Nandrolone, Stanozolol, and Testosterone are allowed to be used. (this is a minimum standard - some racing jurisdictions have even higher restrictions on medications)

In 2008, the Committee implemented a rule requiring that toe grabs on the horseshoe, designed to improve traction, be no longer than 2 millimeters. This was in response to studies by Dr. Susan Stover showing that such toe grabs substantially increase the risk of catastrophic racing injuries. They have also discussed a phase out on the race day use of furosemide (Lasix).

A newly established race may inherit the graded status of a discontinued race if it is held at the same facility under essentially identical conditions as the discontinued race. Notably, the inaugural running of the Pegasus World Cup in January 2017 was Grade I, inheriting the status of the now-discontinued Donn Handicap.

Levels

There are four different levels of grading, from Listed at the bottom to Grade I at the top. The latter are higher-class races for bigger prizes for horses of the same age group (2, 3 or 3 and up) and may further be restricted by gender. The weight conditions of the races may vary provided they meet the Committee's standards to ensure competitiveness. Many grade I races are 'weight-for-age', with weights adjusted only according to age and gender, and also there are 'set weights' where all horses carry the same weight (usually applicable when all horses are of the same age and gender). Furthermore, there are 'conditions' races, in which horses carry weights that are set by conditions, such as having won a certain number of races, or races of a certain value. Finally, some graded stakes are 'handicaps', in which an official handicapper assigns weights to each horse in an attempt to equalize the competition.

Note that all Grade I races must have a purse of at least $300,000, but not all races with such high purses are Grade I. For example, the racetrack may be offering a high purse to attract better fields so the race will be upgraded in future years. The grade level is assigned by looking at data that indicates quality of the field for the last five years. In order to achieve or maintain a Grade I, it is necessary to attract a competitive field over a number of years.

For graded turf races, track conditions (normally excessive rain) may sometimes force the race to be run on the main (dirt) track. If this happens, the race is automatically downgraded by one grade level for that running only. The Committee then reviews the race within five days and may restore the original grade. For example, a Grade I turf race that is switched to the dirt will be recorded as a Grade II race, unless the committee feels the quality of the race was sufficient to warrant Grade I.

In the United States and Canada, a graded race can be dormant for one year without losing its grade. ..." Please continue reading Wikipedia Article: Graded Stakes Race

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