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

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

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

The changes are the very first in what could end up being a wave of legalisation after the Supreme Court last month cleared the method for states to permit sports betting.

The market sees a "once in a generation" opportunity to develop a brand-new market in sports-mad America, said Dublin-based financial analyst David Jennings, who heads leisure research study at Davy.

For UK companies, which are grappling with debt consolidation, increased online competitors and harder rules from UK regulators, the timing is especially opportune.

Why the gaming industry faces an unpredictable future

How does illegal sports betting work and what are the fears?

But the industry states relying on the US remains a risky bet, as UK business face complicated state-by-state policy and competitors from established regional interests.

"It's something that we're really focusing on, however equally we don't desire to overhype it," said James Midmer, representative at Paddy Power Betfair, which recently purchased the US fantasy sports site FanDuel.

'Require time'

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

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

The judgment found the law was an over-reach of federal power. But the court it did not actually legalise sports betting, leaving that question to local legislators.

That is anticipated to cause significant variation in how companies get certified, where sports wagering can happen, and which occasions are open to speculation - with big implications for the size of the market.

Potential income ranges from $4.2 bn to practically $20bn yearly depending upon elements like the number of states transfer 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 big'", said Will Hawkley, London-based head of leisure for consultants KPMG.

Now, he said: "I think the majority of individuals ... are looking at this as, 'it's a chance 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, predicts that 32 states will legalise sports wagering in some type by 2023, creating a market with about $6bn in yearly earnings.

But bookmakers face a far different landscape in America than they carry out in the UK, where wagering stores are a frequent sight.

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

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

States have actually likewise been slow to legalise numerous kinds of online gaming, despite a 2011 Justice Department opinion that appeared to get rid of obstacles.

While sports wagering is usually seen in its own category, "it clearly stays to be seen whether it gets the kind of momentum people think it will," stated Keith Miller, law teacher at Drake University and co-author of a book about sports betting policy.

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

Now an expert, he states UK firms ought to approach the market thoroughly, selecting partners with caution and avoiding mistakes that could cause regulator backlash.

"This is a chance for the American sports gambler ... I'm uncertain whether it is a chance for service," he says. "It really is reliant on the outcome of [state] legislation and how the business operators pursue the chance."

'It will be partnerships'

As legalisation starts, sports wagering firms are lobbying to ward off high tax rates, in addition to requests by US sports leagues, which want to gather a portion of income as an "integrity cost".

International companies deal with the included obstacle of a powerful existing gaming market, with gambling establishment operators, state-run lottos and Native American tribes that are seeking to defend their grass.

Analysts state UK firms will need to strike collaborations, offering their knowledge and technology in order to make inroads.

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

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

'It will just depend'

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

The business has been buying the US market because 2011, when it bought three US firms to develop an existence in Nevada.

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

It works as threat supervisor for the Delaware Lottery and has invested millions alongside a local designer in a New Jersey horse racing track.

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

"We definitely intend to have a very considerable brand name existence in New Jersey," he said. "In other states, it will simply depend upon regulation and potentially who our local partner is."

"The US is going to be the most significant sports betting wagering market worldwide," he included. "Obviously that's not going to happen on day one."