Simply put, conditions are the type of race that is being run. Race conditions, also referred to as the “class” of a race, fall into five broad, and sometimes overlapping, categories:
Maiden: for horses which have never won a race.
Claiming: for horses which are entered for sale at a set price.
Allowance: for horses which have won at least one race and may not be ready for stakes competition.
Stakes: in which horses run for a purse supplemented by nomination, entry, or starter fees.
Handicap: in which horses are assigned weights based on past performances.
All races may be restricted by age, sex, or state breeding programs. In claiming and allowance races, additional restrictions may take the form of “nonwinners” or “classified” conditions that must be met in order a horse to be eligible for entry. In maiden, claiming, allowance, and stakes races, weight assignments may be based on age, sex, or nonwinners conditions.
Let’s take a look at a few examples of conditions in each category.
Maiden
Maiden races offer some of the most straightforward conditions a handicapper will encounter. A maiden race will be either a special weight — so called because weights are arbitrarily assigned based on age — or a claiming race, in which each starter is entered for sale at a set price.
A maiden special weight:

A maiden claiming race:

Claiming
In a claiming race, every horse is for sale, always at a price established by the conditions of the race. Claiming prices can range from the low ($5,000) to the high ($150,000), and are used to draw fields in which the horses entered are of similar value, quality, and ability.
A claiming race:

Restricted claiming races limit starters to horses that have not won a certain number of races lifetime or within a set period.
A restricted claiming race:

Allowance
Conditions for allowance races can be some of the most cryptic on a card. Without the price-sorting mechanism of claiming races, racing secretaries must rely on restrictions such as “Nonwinners of a race other than maiden or claiming,” or “Nonwinners twice other” to attract evenly-matched fields. Classified conditions are used with similar intent. Often written for older horses, classified allowances stipulate that starters have not won a race or a specified amount of money in a set period of time. In general, the more wins and higher earnings allowed within a shorter period, the stronger the field. The variations on nonwinners and classified conditions are many.
A nonwinners allowance:

A classified allowance:

Another variation on the allowance race is the optional claiming race, which combines elements of allowance and claiming conditions. Horses entered in an allowance-optional claimer must either meet the allowance conditions or run for a price.
An allowance-optional claimer:

Starter allowances also occasionally appear on racecards. These races are restricted to horses that have been running in claiming company at a specified level.
A starter allowance:

Stakes
In stakes races, owners usually pay a nomination, entry, or start fee to run a horse. All fees are added to the purse (added money). Stakes can be run under weight-for-age or handicap conditions, and may be restricted by conditions other than age or sex. The most common restriction is that for “state-breds,” horses bred in the state in which the race is scheduled.
A restricted stakes:

A common type of ungraded stakes race is the “overnight stakes,” so called because the nominations for the stakes are usually taken within a week or less before the race is run. Unlike most stakes races, overnight stakes do not usually require a nomination, entry, or start fee; overnight stakes often attract quality horses which have been competing in allowance races.
An overnight stakes:

The top tier of racing at any track are the graded stakes. These races, which are assessed and graded annually by the North American Graded Stakes Committee, draw the best horses in competition, often for generous purses. Stakes can be Grade 3 (the lowest grade, and the most common), Grade 2, or Grade 1 (the highest grade).
A graded stakes:

Handicap
In handicaps, horses are assigned weight by a racing secretary or track handicapper based on past performances. The best horse will carry the highest weight, the least competitive horse the lowest. Handicaps can be ungraded or graded stakes.
A graded handicap:

Starter handicaps are also carded by some racetracks. Like starter allowances, these races are for horses that have been running in claiming company.
A starter handicap:

No overview of race conditions can cover every permutation: Racing secretaries are a creative lot. To get a sense of what conditions are possible on your local circuit, skim the condition books (example) issued by racetracks before and during a meet. Condition books list all the races that may be carded on any given raceday, and are often made available on a racetrack’s web site.



Thanks, Jessica.
With your help, I will be a good handicapper.