Share 
Historical horse racing (HHR) occupies a unique space in American gaming. While it looks and plays like a slot machine, it is legally classified as horse race wagering. That distinction allows it to operate in US states where traditional casino slot machines are restricted or prohibited.
This guide explains how historical horse racing works, compares it with parimutuel betting and offers insight into which option may be best for you.
What is historical horse racing?
Historical horse racing allows players to wager on real horse races that took place in the past, sometimes years or even decades ago. Before placing a bet, players do not know which race they are wagering on. Horse names, jockeys, tracks and dates remain hidden.
Instead, players are shown anonymized data such as past performance statistics and odds ranges. This information is intended to help guide betting decisions. Once a wager is placed, the machine reveals the actual race and displays the historical result.
This structure separates historical horse racing from traditional slot machines. Although the machines look similar, historical horse racing does not use random number generators. Every outcome is tied to a real race that already occurred. Players are betting on historical results, not computer-generated outcomes.
Why historical horse racing exists
Historical horse racing emerged as a response to regulatory limitations. Many states permit parimutuel horse race betting while banning or heavily restricting casino-style slot machines. Historical horse racing bridges that gap.
Because wagers are based on real horse races and follow parimutuel rules, the games qualify as legal gambling activity under certain state laws. This classification allows racetracks to install machines that resemble slots without violating gambling restrictions, creating an additional revenue stream for operators.
How historical horse racing machines work
Historical horse racing machines feature familiar slot-style elements such as reels, buttons and animated graphics. While they may seem confusing at first, the process is relatively simple:
- A player places a wager.
- The wager enters a shared parimutuel betting pool.
- The system assigns a historical race.
- The race outcome determines the result.
- Winnings are paid from the pool.
Multiple players can wager on the same historical race pool at the same time. Winning bets split the pool according to traditional parimutuel payout rules. The machine displays odds based on the pool but does not manipulate them.
Is historical horse racing skill-based or chance-based?
Historical horse racing falls somewhere between chance and skill, depending largely on the player’s experience. Machines typically provide limited data, such as speed figures, previous finishing positions and odds ranges.
Experienced horse racing fans may use this information to make more informed decisions. However, the data is restricted, and most casual players rely on instinct rather than analysis. While knowledgeable bettors may perform better at times, there is no guarantee of a consistent advantage.
What is parimutuel betting?
Parimutuel betting is commonly used in horse and greyhound racing. All wagers are placed into a single pool, and winnings are distributed among those who bet on the correct outcome after taxes and the operator’s commission are deducted.
This system does not offer fixed odds. Bettors do not know their exact payout when placing a wager because returns are based on how much money is wagered on each outcome. Final payouts are determined only after the event concludes.
HHR vs. parimutuel betting: the core difference
The primary difference between historical horse racing and traditional parimutuel betting lies in presentation, not structure. Both systems:
- Use shared betting pools
- Pay winners from player wagers
- Deduct a fixed operator fee
- Avoid a traditional house edge
The difference is in how players engage with each format. Historical horse racing is based on past races, conceals key details and delivers results quickly in a slot-style format. This creates fast-paced gameplay and near-instant outcomes.
Traditional parimutuel betting focuses on live or upcoming races. Bettors have access to complete race information, making handicapping more detailed and time-intensive. The process also takes longer, as wagers are settled after the race is run.
Legal status of historical horse racing in the US
Historical horse racing is legal in some US states but not others. Its legality depends on how state laws define horse racing and parimutuel wagering. Some regulators view it as a lawful extension of horse racing, while others classify it as an illegal slot machine.
Historical horse racing machines are currently available in Kentucky, Virginia, West Virginia, Wyoming, Idaho, Kansas, Arkansas and New Mexico.
In 2025, Alabama lawmakers discussed approving historical horse racing terminals at two Greene County racetracks after a broader gambling bill failed, underscoring continuing legal uncertainty.
Choosing between HHR and parimutuel betting
Historical horse racing may appeal to players who:
- Prefer fast-paced gameplay
- Are new to horse racing
- Bet casually
- Enjoy slot-style machines
Traditional parimutuel betting is better suited for:
- Horse racing enthusiasts
- Players who enjoy in-depth analysis
- Bettors who follow live races
Both models support the racing industry, but they do so in different ways.
What to know before you play
Historical horse racing is not a slot machine, despite its appearance. It is a parimutuel betting system based on past horse racing events. This structure allows racetracks to operate legally in states with strict gambling laws.
The key differences between historical horse racing and traditional parimutuel betting are speed, presentation and transparency. Historical horse racing emphasizes quick, simplified play, while parimutuel betting focuses on analysis and live competition.
Understanding these distinctions helps players make informed decisions about what they are betting on and why each system operates the way it does.
