The Bar Price is a price quoted for contestants in any kind of race or contest that aren’t quoted individually in betting shows, simply because they’re further out in the market.
In this way, the Bar Price works as an abbreviation or a form of “shorthand” for use in the media and by pundits and bookmakers etc. when talking about the rest of the field that is relatively unfancied compared to the first few favourites.
So, for example, let’s say you’re watching the build-up to the UK’s biggest single betting event, the Grand National at Aintree, one Saturday early in April and the TV commentator tells you that horse A is the 7-1 favourite, horse B is 9-1, horse C is 11-1 and so on all the way up to perhaps the tenth horse in the betting market at, say, 20-1. At this point, he or she might say 25-1 bar the field, or simply 25-1 bar. This means that the rest of the runners at that time aren’t quoted in individual prices because it’s quicker and more efficient not to bother at the time as horses beyond this point in the market are relatively unfancied.
This doesn’t mean that you won’t be able to get a price if you want a longshot punt on one of those outsiders beyond the Bar Price; it’s simply a shortcut in the interests of expediency.
It’s a simple way of saying that any entrant not listed is, in this particular example, currently available at odds of at least 25-1, and probably better in practice. This can be frustrating for gamblers in events where prices are sought for fancied long-shots etc., but individual prices beyond the Bar Price should be available online from your preferred bookmaker or exchange, or in betting shops on request.
Of course, the Bar Price doesn’t apply solely to horse racing (though admittedly it is most commonly used in this area). For example, the betting market for the Premier League may read something like this: Manchester City 7/4, Manchester United 9/4, Chelsea 5/1, Arsenal 9/1, Liverpool 12/1, and Tottenham Hotspur 13/1, 66/1 bar. This means that every other Premier League side is quoted at 66/1 or bigger. In this case, the Bar Price is particularly useful as the six clubs quoted are perceived by the market to have markedly better chances than the rest of the field.