5 things you need to know about the British Open

The 143rd British Open is set to begin Thursday at Royal Liverpool Golf Club in Hoylake, Merseyside, England for the 12th time.

The tournament is the third major on the PGA Tour schedule and will mark Tiger Woods' return to major competition, after undergoing back surgery in March. Royal Liverpool is also the only Open course with a par-5 18th.

Related: Your A-Z Guide to the 2014 British Open

Here are five things you need to know:

The Open returns to Royal Liverpool 

The 7,312-yard course designed by Harry Colt has stayed relatively untouched since 1871 save for tweaks made to accommodate the advancement of equipment.

One of the oldest courses on the PGA Tour, Royal Liverpool was awarded the 2006 Open Championship after a 39-year break from the course. The players started on the 17th hole and worked their way around to 16.

Related: 3 things to know about Royal Liverpool Golf Club

The course has hosted 11 Opens, its first in 1897 when Harold Hilton won his second Challenge Belt (now the Claret Jug, formally known as The Golf Championship Trophy) as an amateur.

Royal Liverpool's last winner? Tiger Woods.

Phil Mickelson looks like a longshot

Last year's Open Champion at Muirfield was Phil Mickelson, and since then his game has taken a turn for the worse. He still remains without a top-10 finish this season and is struggling with consistency.

The drop off in Mickelson's game is baffling. From three-time Masters winner to missing the cut this season for the first time in 17 years. From six runner-up finishes at the U.S. Open to tied for 28th. British Open champion in 2013, to first top-10 finish? That remains to be seen.

Related: Groupings, tee times for the British Open

Mickelson's fallen from world No. 2 to world No. 13 in less than 12 months. He has improved, although very little, his driving accuracy and distance. His putting let him down the most this season, ranked 109th, compared to sixth last season.

It doesn't look like there will be a repeat champion at Royal Liverpool.

Tiger Woods makes his major return

After missing both the Masters and the U.S. Open, Tiger Woods is fit to make a comeback, and will appear in his first major of the season at the Open.

Woods won his last British Open in 2006 at Hoylake, completing back-to-back titles after a 2005 win at St Andrews in Scotland.

The Open is Woods' favorite major, that hasn't changed for 17 years. "You can have so many different weather conditions," he said. "That's one of the unique things about the British Open and why it's my favorite major championship."

Related: Updated odds to win the British Open: Tiger leaps forward

With an ailing back, Woods made three cuts but withdrew at The Honda Classic after three rounds in March. He returned to the course after surgery in late March on June 29 at the Quicken Loans National, where he was cut after a 7-over finish through 36 holes.

It isn't likely Woods will capture his fourth career Open Championship at Hoylake, but his presence will bring much-needed attention back to the sport.

Martin Kaymer, Jordan Spieth could be at it again

World No. 12 Martin Kaymer is having the best year of his career. He won The Players Championship and, weeks later, the U.S Open, in most impressive fashion, his first major title since winning the PGA Championship in 2010.

Jordan Spieth, only 20, didn't have a great showing at the U.S. Open (T17) but has finished second twice this season at both the Masters and the Hyundai Tournament of Champions. His fourth-place finish at the Players Championship was equally impressive.

Related: 3 golfers with the most to gain at the British Open

Both players put on a show when it counted and the third major of the year is the perfect time to excel once again.

Runners-up tend to become champions

In the last 10 years, two runners-up at the British Open have come back to win the championship. 

Ernie Els finished second in 2004 and won the tournament for the second time in 2012 (his first win came in 2002). Mickelson finished shy of the championship in 2011, tied with Dustin Johnson, and won the Open in 2013.

This bodes well for Adam Scott and Henrik Stenson, the top-two golfers in the world according to the world rankings, as they've finished as runners-up in the last two years. They've got an excellent chance to continue the trend.

World No. 2 Stenson continues to steadily improve his game. His best finishes this season were the Arnold Palmer Invitational (T5) and the U.S. Open (T4).

Scott continues to lead the pack nine weeks running as the No. 1 golfer in the world. He finished third at the Arnold Palmer Invitational, won the Crown Plaza Invitational in May, and has finished in the top 10 in six of the 10 tournaments he's played in 2014.