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

From Tuesday, new guidelines on wagering entered into impact in Delaware, a small east coast state about 2 hours from Washington.

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

The modifications are the first in what might end up being a wave of legalisation after the Supreme Court last month cleared the method for states to allow sports betting.

The industry sees a "once in a generation" opportunity to develop a 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 grappling with consolidation, increased online competition and harder guidelines from UK regulators, the timing is particularly appropriate.

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But the industry says depending on the US remains a risky bet, as UK business face complex state-by-state policy and competitors from entrenched local interests.

"It's something that we're actually focusing on, but equally we don't desire to overhype it," said James Midmer, spokesman at Paddy Power Betfair, which just recently acquired the US dream sports site FanDuel.

'Take time'

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

Firms are intending to take advantage of more of that activity after last month's decision, which struck down a 1992 federal law that disallowed states beyond Nevada and a few others from authorising sports wagering.

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

That is anticipated to result in considerable variation in how firms get licensed, where sports betting can happen, and which occasions are open to speculation - with big implications for the size of the marketplace.

Potential revenue varieties from $4.2 bn to practically $20bn every year depending upon factors like the number of states transfer to legalise, Oxford Economics estimated in a 2017 study for the American Gaming Association.

"There was a lot of 'this is going to be huge'", said Will Hawkley, London-based head of leisure for consultants KPMG.

Now, he said: "I believe many people ... are looking 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 require time'."

'Remains to be seen"

Chris Grove, managing director at Eilers & Krejcik Gaming, anticipates that 32 states will legalise sports betting in some form by 2023, developing a market with about $6bn in yearly revenue.

But bookmakers deal with a far various landscape in America than they carry out in the UK, where betting 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 imagination, sports betting wagering has long been connected to a 1919 baseball World Series match-fixing scandal.

States have also been sluggish to legalise lots of forms of online gaming, in spite of a 2011 Justice Department opinion that appeared to remove barriers.

While sports betting is normally viewed in its own category, "it plainly stays to be seen whether it gets the type of momentum people believe it will," said Keith Miller, law professor at Drake University and co-author of a book about sports betting policy.

David Carruthers is the former president of BetonSports, who was arrested in the US in 2006 for running an offshore online sportsbook and served jail time.

Now a specialist, he says UK firms must approach the marketplace carefully, selecting partners with caution and avoiding missteps that might result in regulator reaction.

"This is an opportunity for the American sports betting wagerer ... I'm uncertain whether it is a chance for organization," he states. "It actually depends on the outcome of [state] legislation and how business operators pursue the chance."

'It will be partnerships'

As legalisation starts, sports betting wagering companies are lobbying to fend off high tax rates, along with demands by US sports betting leagues, which desire to collect a percentage of earnings as an "stability charge".

International business face the included obstacle of a powerful existing gaming market, with casino operators, state-run lotteries and Native American people that are looking for to protect their turf.

Analysts say UK companies will need to strike collaborations, providing their know-how and innovation in order to make inroads.

They indicate SBTech's current 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 everybody, however it will be collaborations and it will be driven by technology," Mr Hawkley stated.

'It will simply depend'

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

The business has been investing in the US market given that 2011, when it bought three US companies to establish a presence in Nevada.

William Hill now uses about 450 people in the US and has announced partnerships with casinos in Iowa and New Jersey.

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

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

"We certainly intend to have a very significant brand name existence in New Jersey," he said. "In other states, it will simply depend upon guideline and potentially who our regional partner is."

"The US is going to be the greatest sports wagering market in the world," he added. "Obviously that's not going to occur on the first day."