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

From Tuesday, brand-new rules on betting came into impact in Delaware, a tiny east coast state about two hours from Washington.

Neighbouring New Jersey might start accepting sports betting 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 permit sports wagering.

The market sees a "once in a generation" chance to establish a brand-new market in sports-mad America, stated Dublin-based monetary expert David Jennings, who heads leisure research at Davy.

For UK firms, which are coming to grips with combination, increased online competitors and tougher guidelines from UK regulators, the timing is especially appropriate.

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But the market states counting on the US remains a dangerous bet, as UK business deal with complicated state-by-state regulation and competitors from established regional interests.

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

'Take time'

The US accounted for about 23% of the world's $244bn (₤ 182bn) in video gaming profits in 2015, according to a report by Technavio, external released in January.

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

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

That is expected to cause considerable variation in how companies get licensed, where sports betting can take place, and which events are open to speculation - with big ramifications for the size of the market.

Potential income ranges from $4.2 bn to nearly $20bn each year depending upon factors like the number of states move to legalise, Oxford Economics estimated in a 2017 study for the American Gaming Association.

"There was a lot of 'this is going to be substantial'", stated 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 however 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, forecasts that 32 states will legalise sports wagering in some form by 2023, creating a market with about $6bn in yearly revenue.

But bookies face a far various landscape in America than they carry out in the UK, where betting stores are a frequent sight.

US laws restricted betting mainly to Native American lands and Nevada's Las Vegas strip till fairly recently.

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

States have also been sluggish to legalise many forms of online betting, regardless of a 2011 Justice Department viewpoint that appeared to get rid of obstacles.

While sports betting is usually seen in its own classification, "it clearly remains to be seen whether it gets the type of momentum people believe it will," said Keith Miller, law teacher at Drake University and co-author of a book about sports betting wagering regulation.

David Carruthers is the previous president of BetonSports, who was detained in the US in 2006 for running an offshore online sportsbook and served prison time.

Now a specialist, he says UK firms should approach the market carefully, selecting partners with care and preventing bad moves that might lead to regulator reaction.

"This is a chance for the American sports betting wagerer ... I'm not exactly sure whether it is a chance for service," he states. "It truly depends on the outcome of [state] legislation and how the service operators pursue the opportunity."

'It will be partnerships'

As legalisation begins, sports betting companies are lobbying to fend off high tax rates, along with requests by US sports leagues, which want to gather a percentage of profits as an "stability cost".

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

Analysts state UK firms will require to strike partnerships, offering their expertise 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 deals most likely to materialise.

"It will be a win-win for everybody, however it will be partnerships and it will be driven by technology," Mr Hawkley stated.

'It will simply 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 given that 2011, when it acquired three US firms to develop a presence in Nevada.

William Hill now employs about 450 people in the US and has actually revealed collaborations with casinos in Iowa and New Jersey.

It works as threat manager for the Delaware Lottery and has actually invested millions together with a local developer in a New Jersey horse racing track.

Mr Asher said William Hill has become a family name in Nevada but that's not necessarily the goal everywhere.

"We definitely intend to have an extremely significant brand existence in New Jersey," he stated. "In other states, it will just depend upon regulation and possibly who our local partner is."

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