The Olympic Club’s Lake Course is the perfect venue for a competition edged with a bit of architectural controversy. Blend narrow fairways, overhanging trees, oddly-placed bunkers and tilted putting surfaces, and you’ve a recipe for debate and finger-wagging. Thursday at the 2021 U.S. Women’s Open saw eight golfers break 70, seven more break par, and a few leave the grounds of the venerable San Francisco club scratching their heads, uncertain over what just happened.

The co-leaders stand at 4 under par after 18 holes. Some 25 other golfers finished within four shots of that number. With 54 holes left to be played, much remains unknown about this year’s event. Nevertheless, there were five things that we learned on Thursday at the national championship of the USA, so let’s unpack them and find out more about the 2021 US Women’s Open.

1. Angel Yin might finish it off this year

Two years ago, the long-hitting youngster tied for 2nd at the national open championship. Held at the country club of Charleston, the event featured a traditional golf club with a demanding golf course. Yin held up well and used the event as a springboard toward making her second U.S. Solheim Cup side. This year, Yin was the only player in the top 10 to truly solve the closing holes at Olympic. While everyone else gave shots back at the par 5-par 4 concluding stretch, Yin gained back three strokes with hear eagle-birdie finish. Sure, it might be an early-week, one-time fluke. If we see her repeat the feat, watch out for Yin come Sunday.

2. Being the best doesn’t work out every week

Nelly Korda is currently ranked fourth in the world, the highest rung for any golfer from the USA. Korda opened with 78 at Olympic, good for a tie for 119th spot, 11 shots behind the leaders. Other big numbers turned in by pre-event favorites were 76s from Sophia Popov and amateur Rose Zhang, and 75s from Patty Tavatanakit and Anna Nordqvist. Korda was undone by a triple-bogey seven at the 260-yard seventh hole. The young Floridian lost a hybrid right, slashed around the rough a bit, and took three putts from the top of the two-tiered green. Olympic will demand immeasurable amounts of patience from its winner this week. If it is to be Nelly Korda, she will need to complete an incredible comeback.

3. Just don’t lose the tournament on day one

It’s an old adage, and pairs with the notion that no one wins an event on day one. Golfers like Inbee Park, Lydia Ko, and Ariya Jutanugarn didn’t light the course up on Thursday, but they didn’t handcuff themselves, either. Each shot even-par 71 to preserve a chance at the title. At minus-one are Jeongeun Lee6 (the 2019 winner of this event) Jennifer Kupcho, and Marina Alex. A case can be made for any of these golfers to be in contention on Sunday afternoon. Unlike those who struggled, these golfers found a way to preserve a shot at the title. Most days at the Open, it’s not about the birdies you made, but the bogies that you avoided.

4. Defending champion A Lim Kim struggles

As dominant and poised as the young Korean golfer was at Champions last December, she was not today at Olympic. Kim scribbled two 7s and six 5s on her scorecard, on her way to an opening 79. Golf is fickle, and major-championship golf, doubly so. Kim never locked into the quirky California course. She stood three over par before she reached the third tee, and didn’t make a birdie until the 15th green. 2020 runners-up Amy Olson and Jin Young Ko are shaking their heads, wondering where this round was last December for Kim. Incidentally, Ko opened with 70, while Olson signed for 73, during this year’s opening day.

5. And the winner is …

It’s never to early to make an incorrect prediction on who will hoist the sizable trophy on Sunday! I like Lexi Thompson, the long-hitting Floridian. Lexi has never proven that she can win on narrow, nail-biter courses, but 2021 shows us a new and improved model, built for U.S. Open success. Thompson opened with 69, and finds herself two behind English pro Mel Reid and USA amateur Megha Ganne, the round-one leaders. Thompson won’t go low any of the next three days, but she will play consistent golf and win her second professional major title.