Jordan Spieth was not exactly sure of the cut rules at the Masters.

Good thing.

Spieth struggled with a first-round 3-over par 75 on Thursday. His didn’t get off to the best start when he bogeyed No. 1 on Friday, his second straight blemish on the opening hole. However, the 2015 Masters champion finished with five birdies over the final 17 holes to card a 4-under 68. He went with flirting with missing the cut – which would have been a first – to a two-day total of 1-unde par. Spieth is in red numbers and not so far off the leaders.

“The first hole for sure,” Spieth said when asked if he thought about missing the cut. “I'm like, I thought it was (top) 60 and ties, (caddy) Michael (Greller) told me ‑ because I've never been anywhere near it ‑ so Michael told me, it must have been on 15 or 16, and I'm like, it's 10 off the lead and 60 right? He goes, no, it’s 50. And I'm like well good thing I didn't probably know that.”

Indeed, the cut at the Masters is top 50 and ties and within 10 strokes of the leader, a threshold that began in 2013. It was 44 from 1962-2012 and 40 from 1957-61.

Spieth had never flirted with the cut at the Masters before. In his previous four tournament he has won, tied for second twice and tied for 11th once. He is comfortably inside the cut line now after an about face on Friday.

Spieth pointed to two differences for the reversal of fortune.

One, he said he played better from tee to green. With more greens in regulation came less pressure on his putter. He called them stress-free.

Two, he discovered a crack in his driver in a post-round practice session on Thursday. Titleist delivered a backup driver and Spieth was in better position. After hitting 7 of 14 fairways and 10 of 18 greens in Round 1, he hit 10 of 14 fairways and 13 of 18 greens in Round 2.

“I think it's getting really close to being in full control and able to have kind of the ball striking like today on a regular basis if not better,” Spieth said. “So I feel really good about today's round and what you're saying as far as some momentum going forward, just on my progression.”

Spieth said his confidence grew with back-to-back birdies on Nos. 9 and 10. He made a 28-foot birdie putt to end his front nine.

There were chances for a better score. Spieth missed a six-foot birdie putt on No. 17. He three-putted the No. 15 green from 45 feet after hitting the par 5 in two shots.

Spieth is six strokes behind the leaders on the crowded leaderboard going into the weekend. He says don’t count him out just yet.

“As far as this tournament, I’m six back, if I can somehow cut it to three by Sunday, then I feel like I have a legitimate chance,” Spieth said.