Read your article about bingo machines. There's another type of slot machine called Historical Horse Racing, which is used in Kentucky and other states. Wikipedia has a section on it, but it's very confusing. Maybe you could feature it in a Question of the Day and explain how it works in a clear fashion.
Also known as "instant racing," historical racing machines (HHR) look and operate much like slot machines. However, instead of randomizing the outcome of a play like regular slot machines that use a random number generator, HHRs determine winners based on previously run horse races.
On these machines, you bet on the outcome of races, just like you would at any Off Track Betting parlor or horse-racing track. The difference is that you’re betting on actual past races. In other words, you don't have to wait around for the race to be run; it's like hitting a fast-forward button for the result, which renders your bet an instant winner or loser.
Here's how KnowYourSlots.com expresses it. "The machines are set up so you can choose to watch or replay the actual outcome, if that interests you. Or you can tuck it away and focus on the reels, which simply animate an outcome that coincides with the results of your wager. Bonuses are therefore completely predetermined, as the outcome of the horse race was decided in the past, so the game is just providing slot machine-style entertainment."
Here's our explanation.
When a bet is made, a race is randomly selected from a video library of nearly 100,000 of them. Obviously, no identifying information, such as where and when the race was run and which horses and jockeys participated, is revealed. You can do your own "handicapping" by viewing a "skill graph" from the Daily Racing Form, which shows winning percentages of the anonymous jockeys and trainers and the horses' post positions; then you pick the order in which you believe the horses will finish the race. However, since HHR are, for most intents and purposes, slot machines, players usually opt for the "handi-helper" or "auto-cap" function, which enables the machine to select the order for you. Finally, an animated display of the race appears on the screen via spinning reels reminiscent of a slot.
Essentially, like Class II slot machines at tribal casinos that are based on bingo games, rather than the RNG, HHR machines circumvent restrictions against typical slot machines in states that impose them. In Kentucky, for example, which has the most historical horse racing machines, the state constitution allows only the state lottery, charitable gaming, and pari-mutuel wagering. So gaming-device manufacturers came up with the horse-racing machines to skirt the edge of the law: slot machines with pictures of horses on them, in order to exist within the pari-mutuel realm.
That doesn't mean that they're not controversial. In September 2020, the Kentucky Supreme Court ruled that the machines don't constitute pari-mutuel wagering, rendering them unconstitutional in the state. In response, the Kentucky General Assembly acted swiftly in 2021, passing Senate Bill 120. Signed into law by the governor in February of that year, SB 120 redefined "pari-mutuel wagering" under Kentucky Revised Statutes (KRS) Chapter 230 to explicitly include HHR machines. This legislative fix effectively legalized HHR machines, overriding the Supreme Court's narrower interpretation.
Since then, no significant legal challenges have overturned this status, though debates persist about tax rates and the machines' broader impact on gambling policy. Today, Kentucky has 7,000-8,000 of the machines licensed for use at its thoroughbred and racetracks and standalone HHR facilities.
In fact, the definition of HHR was recently (November 2025) expanded to include electronic table games (ETG).
According to HarnessRacingUpdate, "Even though these games resemble roulette, blackjack, and craps, in the eyes of state gaming officials, they are officially recognized as a form of pari-mutuel wagering." The HHR-based ETGs are being introduced at existing HHR facilities (e.g., Derby City Gaming, Ellis Park, Kentucky Downs) to try to keep Kentucky competitive with neighboring states with commercial casinos.
