After undergoing Tommy John surgery last November, Bryce Harper returned to the Phillies’ lineup ahead of schedule on May 3. However, it took much longer for the two-time MVP’s power stroke to make it back.

While Harper posted a .290 average and .383 on-base percentage over his first 77 games this season, he also had just five homers and a .403 slugging percentage in that span. If that slugging percentage held up, it would have set a new career low by 20 points.

But Harper’s power has returned in full force this month. Following Monday's game, in which he homered, he has hit .375 with eight dingers, a triple, six doubles, 20 RBIs and a 1.285 OPS in his past 20 games. His slugging percentage in that time? A healthy .819.

As Harper’s slugging percentage climbs, so too do Philadelphia’s chances of going deep into the postseason for a second straight year.

Harper fueled the Phillies' surprise run to the World Series a year ago with an incredible performance at the plate. In 71 plate appearances during the 2022 playoffs, he hit .349 with six homers, seven doubles, 13 RBIs and a 1.160 OPS.

One of those homers, a go-ahead, two-run blast to left-center field off the Padres’ Robert Suarez in the bottom of the eighth inning during Game 5 of the NLCS, was responsible for sending the Phils to the Fall Classic.

Harper has recaptured that form in August, which has meant two things:

1) More hard contact

While Harper’s rate of producing hard contact (batted balls with 95+ mph exit velocity) was still decidedly above average over his first 77 games, it was nowhere near the borderline elite mark he had in the regular season from 2020-22 or the amazing figure he put up in the 2022 postseason.

Harper’s hard-hit rate breakdown:

• 2020-2022 regular seasons: 49.3% (T-20th of 296 hitters, min. 400 batted balls)
• 2022 postseason: 56% (5th of 48 hitters, min. 15 batted balls)
• First 77 games of 2023: 43.7% (T-109th of 350 hitters, min. 100 batted balls)

However, Harper has returned to his 2022 postseason level over his past 20 games, notching a 56.4% hard-hit rate, the seventh-highest in MLB (min. 50 batted balls).

Highest hard-hit rate since Aug. 5
Min. 50 batted balls

1. Fernando Tatis Jr. (SD): 58.8%
2. Gunnar Henderson (BAL): 58.5%
3. Julio Rodríguez (SEA): 57.3%
4-T. José Ramírez (CLE): 56.7%
4-T. Tommy Pham (AZ): 56.7%
6. Ke'Bryan Hayes (PIT): 56.5%
7. Bryce Harper (PHI) 56.4%

Six of his 11 hardest-hit balls of the season have come during that span, including his hardest-hit homer -- a 112.9 mph, game-tying blast off Giants closer Camilo Doval in the bottom of the ninth inning on Aug. 23.

It was one of four 110+ mph batted balls Harper had on the night. He’s one of three players to produce four such balls in one game under Statcast tracking (since 2015), joining Aaron Judge (five on Sept. 18, 2022) and Giancarlo Stanton (four on May 7, 2015).

But hard contact has only been part of the equation behind Harper’s rejuvenated power stroke this month. Because while hard-hit balls are valuable, hard contact on the ground is a lot less valuable than …

2) More air contact

… hard contact in the air.

Prior to Aug. 5, Harper was hitting far too many balls on the ground. His ground-ball rate was around 50%, curtailing his chances to hit the ball out of the park.

But Harper, whose career ground-ball rate is 42.6%, has been doing a much better job of launching the ball in the air lately. Over his past 20 games, his ground-ball rate has dropped to 30.9%, similar to the mark (32%) he posted during the 2022 postseason.

For Harper, the combination of increased hard contact and increased air contact has caused his rate of producing barrels, batted balls with the optimal combo of exit velocity and launch angle, to soar.

After posting an 11.6% barrel rate over his first 77 games, Harper has recorded 13 barrels on 55 batted balls since Aug. 5, a 23.6% barrel rate. Only one hitter has notched a higher barrel rate in that time.

Highest barrel rate since Aug. 5
Min. 50 batted balls

1. Spencer Torkelson (DET): 24.6%
2. Bryce Harper (PHI): 23.6%
3. Marcell Ozuna (ATL): 18.5%
4. Christian Walker (AZ): 17.7%
5-T. Max Kepler (MIN): 17.6%
5-T. Jorge Polanco (MIN): 17.6%

Again, that looks an awful lot like what Harper did in the 2022 playoffs, when he registered a 24% barrel rate on 50 batted balls.

Harper's resurgence has been part of a big month for the Phillies' offense overall. The club has hit 52 home runs in August, leading the Majors and setting a franchise record for a calendar month.

With free-agent addition Trea Turner getting back on track (7 HR, 1.111 OPS since Aug. 4), Philadelphia's lineup is in as strong of a place as it's been all year.

Of course, the Phils are ultimately going to go as far as Harper's bat can take them come October. With the way he's slugging this month, the 30-year-old looks poised to carry them to another deep postseason run.