Dynamic Duo Carrying an Overachieving Astros Rotation

As we enter July, the Houston Astros once again find themselves in a familiar position: first place in the AL West. At 51-34, they hold a seven-game division lead and boast the best home record in baseball (32-14). But this year’s rise to the top hasn’t come with the usual dominant lineup or deep pitching staff. In fact, it’s been anything but conventional.

The 2025 Astros are more fragile than formidable on paper. Key offensive stalwarts like Yordan Alvarez have been injured since May 2, Alex Bregman and Kyle Tucker are no longer in the clubhouse, and veterans like José Altuve and Christian Walker are posting negative WARs through 81 games. Jeremy Peña, the team’s breakout star with a 4.6 WAR and .322 average, just hit the IL with a fractured rib cage.

And yet, the Astros are thriving. That’s because of two men: Framber Valdez and Hunter Brown, who have stabilized a patchwork rotation. Together, Valdez and Brown have made 33 combined starts in 2025, and the Astros are an incredible 24-9 in those games, including consecutive wins in Valdez’s last 10 starts and Brown’s last six starts entering July 2.

Framber Valdez: The Ground Ball Machine Still Getting It Done

Valdez, the 31-year-old left-handed ace, remains one of the league’s most dependable arms. In 17 starts this year, he’s delivered 13 Quality Starts, including two 8-inning gems and a complete game. Over 109 innings, he owns a 2.72 ERA, 1.13 WHIP, and 3.2 WAR.

A quick look under the hood, though, suggests a little overperformance. His expected ERA sits at 3.77 (53rd percentile), and he ranks in just the 18th percentile in average exit velocity allowed (90.7 mph). That said, Valdez continues to dominate in the ways that make him unique:

• 98th percentile in ground ball rate
  
• 95th percentile in fastball run value (thanks to a nasty sinker)
  
• 93rd percentile in overall pitching run value
  

He uses his sinker 44.6% of the time and curveball 34%, which are both excellent pitches in his arsenal. His changeup is a distant third offering (18.2% usage) and has underperformed in 2025, but it hasn’t held him back from fronting this rotation with consistency and efficiency. Walks (8.9 BB%) are a bit of a concern, but that’s par for the course in Valdez’s game.

The Evolution of Hunter Brown: From Top Prospect to Legitimate Ace

While Valdez has done what he always does, Hunter Brown has emerged as one of the most dominant pitchers in all of baseball. At 26 years old, the former top prospect with Justin Verlander mechanics comparisons has found his stride, and then some.

In 16 starts, Brown has a dazzling 1.74 ERA and 118 strikeouts in 98 innings. His underlying metrics back up the breakout:

• 99th percentile in pitching run value and fastball run value
  
• 93rd percentile in breaking pitch run value
  
• 89th percentile in xERA (2.85)
  
• 92nd percentile in strikeout rate (32.1%)
  
• 96th percentile in hard-hit rate allowed
  
• 98th percentile in average exit velocity allowed (85.4 mph)
  

Brown is overpowering hitters without giving up loud contact. He’s top 10% in chase rate, whiff rat and barrel avoidance, and he even ranks 74th percentile in ground ball rate. The Astros have won his last six starts, and he’ll take the mound tonight (July 2) at Coors Field looking to make it seven.

Brown’s only career start in Colorado came in 2023, when he allowed four runs over 5.1 innings. But he’s a different pitcher now and the Rockies have a different lineup now. Given the Rockies’ league-worst 19-66 record, he’s in a good spot to continue his 2025 dominance.

The Rest of the Rotation: A Collection of Questions

Behind Valdez and Brown, it’s a whole lot of mystery and mild panic.

Brandon Walter

The 28-year-old lefty has been a pleasant surprise. A former 26th-round pick who was released by the Red Sox last August, Walter has pitched to a 3.34 ERA and 1.04 WHIP in 29.2 innings since joining the Astros rotation on May 20. He’s allowed two runs or fewer in four of five starts.

His underlying numbers show promise:

• 89th percentile in average exit velocity
  
• 93rd in chase rate
  
• 100th percentile in walk rate (1.6%)
  
• 84th percentile in ground ball rate
  

Still, the small sample size and career trajectory suggest caution. Walter hasn’t thrown many big-league innings, and the Astros may be pushing their luck asking him to hold down a key rotation spot long-term.

Colton Gordon

The 26-year-old rookie has made nine starts since his May 14 debut. He has a 4.37 ERA, 1.41 WHIP and a 0.3 WAR over 45.1 innings. Gordon doesn’t miss many bats, and his Baseball Savant metrics are bleak:

• 18th percentile in pitching run value
  
• 9th percentile in breaking pitch value
  
• No ground balls, modest whiffs and a lot of contact
  

The positive is that he hasn’t walked anyone (2.9 BB%, 99th percentile). But he’ll need to evolve to remain viable in the rotation.

Ryan Gusto

Gusto has made 11 starts and 18 total appearances, logging a 4.90 ERA and a -0.3 WAR across 64.1 innings. He’s been shaky all year and his June (5.33 ERA) didn’t inspire confidence. The righty ranks in the 10th percentile or lower in nearly every pitching category on Baseball Savant.

Despite 71 strikeouts, Gusto allows too many hits (73) and walks (23) to be effective long-term.

Lance McCullers Jr.

Back from a long injury absence that kept him sidelined since 2022, it’s nice to see one of the longest tenured Astros back pitching. The not so nice thing is that McCullers has been shelled in eight starts since returning to the big-league mound on May 4: 6.61 ERA, 1.62 WHIP and a -0.8 WAR. It’s been a rocky road back, and it’s unclear if he’ll recapture his old form.

Injuries Have Forced the Astros’ Hand

The Astros’ rotation has been ravaged:

Ronel Blanco, who posted a 2.80 ERA in 29 starts last year (4.5 WAR), required Tommy John surgery following his May 17 start, and he is now out for the season. Hayden Wesneski, who was acquired in the Kyle Tucker deal, underwent Tommy John in May. Spencer Arrighetti, another promising arm, broke his thumb in April and has been out since.

Houston’s rotation has been held together with duct tape and the magic known as Framber Valdez and Hunter Brown.

Can They Keep This Up?

There’s a clear argument to be made that the Astros are overdue for regression. They’re 18-7 in one-run games, 5-1 in extra innings and severely overachieving compared to their roster construction. They’ve lost key offensive pieces, and injuries keep piling up.

And yet, they’re here. First place. Winning. Again. They are seemingly inevitable, no matter the circumstances.

That’s what makes Houston so maddening to opponents and impressive to watch. With a decade of sustained excellence behind them, the Astros continue to reinvent themselves on the fly.

It starts with pitching. And as long as Framber Valdez and Hunter Brown are taking the ball every fifth day, Houston’s postseason hopes stay alive. We won’t be surprised if they start to collapse a bit in the second half, but by now, we certainly know better than to doubt this organization.