Brian Harman started the week as a longshot to win the 151st Open. 

Despite a recent surge of low rounds, Harman opened as a 100-to-1 outright betting option. 

Just how good was Harman's recent run of form? Kicked off by a 4-under 66 in round one of the Travelers Championship, he rattled off 11 straight sub-69 rounds en route to a trio of top-15 finishes. His score was at least 1.5 shots better than the field average in all of those rounds, the longest stretch of such rounds in his 1122-round PGA Tour career. 

Fast forward to the midpoint of The Open, and Harman's strong play continues. Buoyed largely by a hot putter, the smooth-swinging lefty holds a five-shot lead over home favorite Tommy Fleetwood. Harman is now +150 on the live odds board, which implies a 40 percent chance to win. 

Is this unchartered territory for the Georgia Bulldog? Not exactly. Sure, this is his first time holding a commanding lead at the 36-hole mark of a major, but he did hold a share of the 36-hole lead at the 2017 U.S. Open, alongside Paul Casey, Brooks Koepka, and the aforementioned Tommy Fleetwood. 

Harman faded on Sunday that week at Erin Hills to settle for a T-2 finish, but is hoping that experience will guide him this week.

"It's just golf," Harman said. "I think when I held the 54-hole lead at the U.S. Open, I just probably thought about it too much. Just didn't focus on getting sleep and eating right. So that would be my focus this weekend." 

Who does Harman need to worry about over the weekend? 

+400 Tommy Fleetwood
The local favorite shared the lead after round one but couldn't keep pace with Harman on Friday. Fleetwood did manage to hole 125 feet worth of putts on day two, keeping his name near the top of the board. 

He'll need his tidy ball-striking skills to return over the weekend. The Southport native opened as a +2800 outright option and is now given a 20 percent chance to win after a strong start. 

+1000 Rory McIlroy
The Ulsterman is looking to snap a major-championship drought that stems back to the 2014 PGA Championship at Valhalla. 

McIlory has pulled driver just 15 times through 36 holes at Hoylake but still managed to capitalize on the tee box, currently ranked first in the field in strokes gained off-the-tee. 

The pre-tournament co-favorite has posted top 10s in 19 (of 33) major championships since that 2014 victory. He has the experience contending in majors and as a result is not feeling pressured despite finding himself nine shots off the pace, "Right now it's not quite out of my hands, but at the same time, I think if I can get to 3, 4, 5 under par tomorrow going into Sunday, I'll have a really good chance." 

The Field
Harman and Fleetwood combine for 60 percent of the win equity according to the live odds. Add in 9 percent from McIlroy and there is still roughly 30 percent of the win equity up for grabs. 

There are eight golfers lurking between 2 under and 4 under with 36 holes to play. That includes Sepp Straka, who finds himself in sole possession of third place after an eight-birdie 67 on Friday. Despite him being three shots ahead of McIlroy, Straka is just +1800 on the live odds board. 

Other notables include Jordan Spieth (+1600), who had a front-nine spark today and Min Woo Lee (+1800), whose hype videos have made him a fan favorite on social media. 

Could there be a surprise contender from the back of the pack? The pre-tournament line for low round of the week was set at 64.5 and only one golfer has eclipsed 66 through two days at Royal Liverpool (Brian Harman's 65 today). It would likely take a sub-65 plus some help from Harman for someone to come from outside of the top 10 over the weekend. 

Brian Harman - boasting just two top 10s in his previous 29 majors played - is in complete control with 36 holes to play, just like we all drew it up on Monday morning. The 36-year-old has two wins to his credit (2014 John Deere Classic, 2017 Wells Fargo Championship) but a win at Royal Liverpool would easily be the best of his career.