The 2019 British Open will be one of golf's most challenging tests, with rainy conditions expected and links-style golf requiring a different approach to the game. This week's 2019 Open Championship figures to live up to that billing at Royal Portrush in Northern Ireland, where daytime highs will only reach the low 60s. After playing collegiality in the United States, Spanish star Jon Rahm has readjusted to links-style golf as a pro and collected a pair of Irish Open wins the last two years. Now, Rahm will seek to capture his first major championship and is going off at 16-1 to win it all in the latest 2019 Open Championship odds. However, he'll have to best a loaded 2019 Open Championship field that also includes favorite Rory McIlroy (8-1), world No. 1 Brooks Koepka (10-1), defending champion Francesco Molinari (20-1) and three-time Open Championship winner Tiger Woods (18-1). The 2019 Open Championship tee times begin at 1:35 a.m. ET early Thursday morning. Before entering your 2019 Open Championship picks and PGA predictions, you need to hear what legendary golf handicapper Sal Johnson has to say. 

A media legend and consummate golf insider, Johnson is red-hot this year. He featured Woods in his best bets for the Masters, and Woods walked away with his fifth green jacket. Then, Johnson promoted Koepka in his PGA Championship best bets, and Koepka made a mockery of that major, building a seven-shot lead entering the weekend and cruising to victory.

Last month at the Travelers Championship, Johnson promoted 50-1 long shot Chez Reavie as a potential winner, citing Reavie's momentum following his third place finish at the U.S. Open and noting how his game (second in fairway accuracy, eighth in proximity to hole) suited TPC River Highlands perfectly. The result: Reavie cruised to a four-stroke victory, finishing 17-under for his first PGA title in 11 years. 

And Johnson knows Royal Portrush like the back of his hand, having covered more than a dozen tournaments there over his storied career.

Now, Johnson -- the first producer of "Inside the PGA Tour," a longtime ABC Sports golf producer and the founder of the world's biggest golf stats database -- has issued his highly confident Open Championship picks 2019. He made those picks, which he's sharing at SportsLine, based on his revealing breakdown of Royal Portrush.

"Seven or eight holes will be perfect for bombers, while the rest of the course will appeal to the shotmaker," Johnson told SportsLine.

We can tell you Johnson wants no part of Woods even though he's in the midst of a resurgent season after winning the Masters. In fact, Johnson says Woods doesn't even crack the top 10 at Royal Portrush. "Tiger complained about the chill in the air at Pebble Beach and said his back wasn't the best in 'sweater weather,'" Johnson told SportsLine. "He also missed the cut at Bethpage Black in the cold. Add in possibly wet and windy conditions and it's not going to be a winning week for Tiger."

Johnson has a strong read on McIlroy, a Northern Ireland native who set the course record at Royal Portrush by shooting a stunning 61 as a 16-year-old at the North of Ireland Championship. The course has changed since then, with new seventh and eighth holes built from scratch and the old 17th and 18th holes now serving as the course's championship village. However, McIlroy will still have a home course advantage. He won this year's Players Championship and RBC Canadian Open and has four consecutive top-five finishes at the Open. However, he's also on a five-year major championship drought.

Johnson also has locked in the fate of Phil Mickelson, who won the 2013 Open Championship at Muirfield and has five major titles to his name. The 49-year-old has had a wildly inconsistent season, missing seven cuts but collecting his 44th PGA Tour victory at the AT&T Pebble Beach Pro-Am. After years of criticism about his inability to handle links golf, Mickelson has a pair of second place finishes to go along with his 2013 win in his last eight tries at the Open. He also recently took the drastic measure of fasting for six days to reset after a poor run, shedding 15 pounds in the process.

Instead, Johnson is high on an astronomical long shot who thrives on links courses, has a top-five Open Championship finish to his credit, and boasts a strong track record at Royal Portrush. "I strongly feel that he not only will contend but can win," Johnson said. Anyone who backs this underdog could hit it big.

Who wins the 2019 British Open? Where do Mickelson and McIlroy finish? And which massive long shot stuns the golf world? Check out the latest 2019 British Open odds below, then visit SportsLine to see Sal Johnson's full leaderboard and picks, all from the golf insider who nailed the Masters and PGA Championship this year.

Rory McIlroy 8-1
Dustin Johnson 10-1
Brooks Koepka 10-1
Jon Rahm 16-1
Tiger Woods 18-1
Justin Rose 20-1
Xander Schauffele 20-1
Francesco Molinari 20-1
Rickie Fowler 25-1
Patrick Cantlay 25-1
Tommy Fleetwood 25-1
Justin Thomas 30-1
Adam Scott 30-1
Louis Oosthuizen 30-1
Henrik Stenson 30-1
Matt Kuchar 30-1
Bryson DeChambeau 40-1
Hideki Matsuyama 40-1
Jason Day 40-1
Paul Casey 50-1
Graeme McDowell 50-1
Matt Wallace 50-1
Tony Finau 60-1
Gary Woodland 60-1
Marc Leishman 60-1
Shane Lowry 80-1
Matthew Fitzpatrick 80-1
Rafael Cabrera Bello 80-1
Sergio Garcia 80-1
Patrick Reed 80-1
Phil Mickelson 100-1
Ian Poulter 100-1
Eddie Pepperell 100-1
Tyrrell Hatton 100-1
Webb Simpson 100-1