It's high stakes for UK companies as sports betting starts to spread in America.

From Tuesday, new guidelines on betting entered into impact in Delaware, a small east coast state about two hours from Washington.

Neighbouring New Jersey could start accepting sports betting bets as early as Friday.

The changes are the first in what might become a wave of legalisation after the Supreme Court last month cleared the method for states to allow sports betting wagering.

The market sees a "when in a generation" chance to establish a brand-new market in sports betting-mad America, said Dublin-based financial analyst David Jennings, who heads leisure research at Davy.

For UK firms, which are facing combination, increased online competition and harder guidelines from UK regulators, the timing is particularly appropriate.

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But the market states counting on the US remains a dangerous bet, as UK companies face complex state-by-state regulation and competition from established local interests.

"It's something that we're actually concentrating on, but similarly we don't wish to overhype it," stated James Midmer, representative at Paddy Power Betfair, which recently purchased the US fantasy sports site FanDuel.

'Take some time'

The US represented about 23% of the world's $244bn (₤ 182bn) in gaming profits last year, according to a report by Technavio, external published in January.

Firms are intending to tap into more of that activity after last month's decision, which overruled a 1992 federal law that barred states beyond Nevada and a few others from authorising sports betting.

The ruling found the law was an over-reach of federal power. But the court it did not in fact legalise sports betting, leaving that concern to local lawmakers.

That is anticipated to cause substantial variation in how companies get certified, where sports wagering can take place, and which events are open to speculation - with huge ramifications for the size of the marketplace.

Potential revenue varieties from $4.2 bn to nearly $20bn annually depending on factors like how lots of states move to legalise, Oxford Economics estimated in a 2017 study for the American Gaming Association.

"There was a great deal of 'this is going to be substantial'", stated Will Hawkley, London-based head of leisure for specialists KPMG.

Now, he stated: "I think the majority of people ... are taking a look at this as, 'it's an opportunity but it's not going to be $20bn and it's going to be state by state and it's going to take time'."

'Remains to be seen"

Chris Grove, handling director at Eilers & Krejcik Gaming, predicts that 32 states will legalise sports betting wagering in some form by 2023, creating a market with about $6bn in annual earnings.

But bookies face a far different landscape in America than they perform in the UK, where wagering stores are a regular sight.

US laws limited gaming mostly to Native American lands and Nevada's Las Vegas strip up until reasonably recently.

In the popular creativity, sports wagering has actually long been linked to a 1919 baseball World Series match-fixing scandal.

States have also been slow to legalise numerous kinds of online gambling, in spite of a 2011 Justice Department opinion that appeared to get rid of challenges.

While sports betting is generally viewed in its own category, "it clearly remains to be seen whether it gets the type of momentum individuals believe it will," stated Keith Miller, law teacher at Drake University and co-author of a book about sports betting wagering guideline.

David Carruthers is the previous primary executive of BetonSports, who was jailed in the US in 2006 for running an offshore online sportsbook and served jail time.

Now a consultant, he states UK firms must approach the marketplace thoroughly, choosing partners with caution and avoiding missteps that could lead to regulator backlash.

"This is a chance for the American sports gambler ... I'm not exactly sure whether it is a chance for company," he says. "It really depends on the result of [state] legislation and how the company operators pursue the opportunity."

'It will be partnerships'

As legalisation begins, sports wagering companies are lobbying to ward off high tax rates, as well as requests by US sports leagues, which wish to collect a percentage of profits as an "integrity charge".

International business deal with the added obstacle of a powerful existing video gaming industry, with casino operators, state-run lotteries and Native American people that are looking for to defend their grass.

Analysts state UK firms will require to strike partnerships, providing their knowledge and technology in order to make inroads.

They indicate SBTech's recent announcement that it is offering technology for Kentucky Derby operator Churchill Downs as an example of the type of offers likely to materialise.

"It will be a win-win for everyone, however it will be collaborations and it will be driven by technology," Mr Hawkley said.

'It will just depend'

Joe Asher, primary executive at William Hill US, is clear-eyed about the realities.

The company has actually been investing in the US market considering that 2011, when it bought three US firms to establish a presence in Nevada.

William Hill now uses about 450 individuals in the US and has actually announced collaborations with casinos in Iowa and New Jersey.

It works as risk supervisor for the Delaware Lottery and has invested millions together with a regional developer in a New Jersey horse racing track.

Mr Asher stated William Hill has ended up being a household name in Nevada however that's not always the objective everywhere.

"We certainly mean to have a very considerable brand name presence in New Jersey," he stated. "In other states, it will just depend on guideline and potentially who our local partner is."

"The US is going to be the greatest sports betting market worldwide," he added. "Obviously that's not going to take place on day one."