Dave Bunker, a 51-year-old amateur from Canada, birdied three of his first five holes on Thursday to vault up the leader board in the 37th U.S. Senior Open, and though he stumbled a bit, he didn’t shoot himself out of the championship at Scioto Country Club.

Bunker, who finished at 4-over-par 74, is one of 23 amateurs in the field this week, and that group has an opportunity to extend a streak of 11 years in which at least one amateur has made the 36-hole cut in the U.S. Senior Open. The last time that no amateurs made the weekend was in 2003 at Inverness Club in Toledo, Ohio.

Bunker, of Woodbridge, Ontario, a physical-education teacher at Lawrence Heights Middle School in Toronto, is no stranger to top-flight competition. This is his second Senior Open, and he has played in two Canadian Opens on the PGA Tour, thanks to victories in the Canadian Mid-Amateur Championship in 2009 and 2010. Bunker qualified for this year’s championship on July 6 by making a birdie on the first playoff hole to earn the lone spot at a sectional qualifier in Export, Pa.

Michael McCoy, of Des Moines, Iowa, has been the low amateur in the past two Senior Opens, tying for 26th place both times, at Del Paso Country Club in Sacramento, Calif., in 2015, and at Oak Tree National, in Edmond, Okla., in 2014. He was one of three amateurs to play the weekend in 2015, and just two in 2014. He opened the week with a round of 5-over 75 on Thursday while playing with 2008 Senior Open champion Eduardo Romero and 2012 champion Roger Chapman.

Pat Tallent, the 2014 U.S. Senior Amateur champion, is the only player besides McCoy in this year’s field who has finished as low amateur in the Senior Open. Tallent, who turns 63 on Friday and is competing in his sixth Senior Open, was the lone amateur to make the cut in 2004 and tied for 54th place. He opened on Thursday with a 3-over 73, the best among the amateurs in Round  1.

The amateur who made the biggest recent splash in the Senior Open is Tim Jackson, who in 2009 led the championship after 36 holes at Crooked Stick. He went on to tie for 11th place, the best showing by an amateur since William Campbell finished second to Roberto De Vicenzo in the inaugural Senior Open at Winged Foot in 1980.

Allen Once Again a Presence

Michael Allen, 57, seems to be in the mix nearly every year in the U.S. Senior Open.

On Thursday morning, Allen opened the championship with a round of 2-under-par 68. He made five birdies that more than offset a double bogey on the par-3 fourth hole. The native of San Mateo, Calif., has three top-10 finishes and has not finished lower than 33rd place in six starts in this championship.

“This is our biggest tournament of the year,” said Allen, who led the 2013 championship at Omaha (Neb.) Country Club for three rounds before Kenny Perry blew past him with a closing 63. “So it's one you like to prepare for and win the most. I would love to win a USGA title. That's what I've always wanted to do since I was a little kid, and it continues today.”

Allen ended up fifth in 2013, and he also has tied for sixth (2010) and seventh (2011) in the Senior Open. He has eight victories since joining the PGA Tour Champions in 2009, and brings a positive frame of mind to the senior game’s premier championship.

“I love playing the golf courses in the Senior Open,” said Allen. “They're always a challenge. It's always fun to come out and play like that. I still get a few more chances at it, so maybe I cherish it a little bit more now.”

No. 8 Shows Its Teeth

Jack Nicklaus, who grew up playing the course at Scioto, was never a fan of the 1960s-era redesign that added a moat around the green on the eighth hole.

“The eighth hole was a wonderful par 5 when I grew up, but it was in an area that flooded a lot,” said Nicklaus, who helped Michael Hurdzan with a more recent renovation. “They decided to put a lake down there, and they put a moat around the green that was there for about 50 years. It was way out of place, and I finally convinced the membership to take the moat out [last year].”

The hole apparently doesn’t need a moat for defense. It played by far the toughest of any hole in the first round on Thursday. The 498-yard par 4 gave up just five birdies while surrendering fewer pars (56) than bogeys (75) on the way to a stroke average of 4.73. There were 16 double bogeys and four scores higher than that.

The bad news for the field? The course setup notes for Round 1 described the back-left hole location for Thursday as the most accessible on the green, so don’t expect it to get any easier.

Notable and Quotable

• Both Philip Golding and Gary Hallberg eagled their first holes of competition on Thursday. Golding holed a 9-iron from 150 yards on the par-4 first and Hallberg holed a gap wedge from 116 yards on the par-4 10th hole.

• Bernhard Langer’s 3-over 73 ties his highest score in his last 29 senior major-championship rounds. It also ties his worst round in relation to par this year on the PGA Tour Champions. He shot a 3-over 75 at the Mitsubishi Electric Classic in April. On a similar note, Tom Watson’s 2-over 72 was the first time since 2004 that he shot over par in the first round of a U.S. Senior Open.

• Dave Eichelberger (11-over 81) started his 22nd consecutive U.S. Senior Open. That is third-most all-time behind Dale Douglass (26) and Arnold Palmer (25).

• “I think I sold my soul to the devil when I won, and now, no matter what I do, I can't do anything right.” – Woody Austin, who has won three times on the PGA Tour Champions this year, but is now struggling with his game. He shot 5-over 75 on Thursday.

Ron Driscoll is the manager of editorial services for the USGA. Email him at rdriscoll@usga.org.