Roger Federer goes for his ninth Wimbledon crown when tennis' premier event begins Monday at the All England Club. Federer is a +180 favorite, followed by Novak Djokovic (+450), Rafael Nadal (+550), Marin Cilic (+800) and Alexander Zverev (+1400).

Before you make your picks, you have to hear what British tennis expert Sean Calvert says. An Essex resident, Calvert has been releasing documented, profitable bets for six straight years, and he owns this event in his home country. In 2016 and 2013, he called Andy Murray winning Wimbledon despite Djokovic entering as the favorite. And Calvert just cashed in huge on John Isner at 100-1 to win the Miami Open.

He also nailed Juan Martin Del Potro to win Indian Wells at 10-1, meaning he's called the outright winner of the last four Masters level tournaments on hard courts. Calvert's legendary calls include Stan Wawrinka to win the 2014 Australian Open at 60-1 and Jack Sock to win the 2017 Paris Masters at 80-1. Anyone who has followed him is way, way up.

Calvert doesn't see Djokovic nabbing his fourth Wimbledon crown. "His grass court stats are excellent and having made the final at Queen's Club last week, he's clearly getting back towards something like his old form, but he's not quite there yet for me," Calvert said.

However, Calvert is highly confident he has the overall winner, and he's also backing a monumental long shot to go extremely deep. Anyone who backs this underdog could reap a colossal payday.

Who wins Wimbledon? And what long shot stuns the tennis world?... Join SportsLine here to see Sean Calvert's Wimbledon picks, all from the acclaimed expert who called Andy Murray's surprising Wimbledon championship and just cashed in huge on John Isner winning the Miami Open at 100-1!