Foster Griffin is an arm to keep an eye on throughout the second half of the MLB Season
TL;DR: Foster Griffin is quietly poised for a second-half breakout for the Nationals, skyrocketing to the #3 ranked qualified MLB starter over the last 30 days (up from #82). The underlying metric shift? He didn't alter his pitch shapes—he optimized his arsenal usage by cutting back on his fastball and throwing more curveballs. Data breakdown below.
Context & Performance: Foster Griffin, a 30-year-old lefty for the Washington Nationals, has had a great year so far, but let's unpack why he might be an X-Factor for the Nationals in a potential second-half playoff push, or for fantasy managers looking to pick up some more firepower in their starting rotation.
Foster Griffin has a 100.4 Composite Score for the year 2026 on Breakfast Baseball, placing him in the top 50 (#48) for qualified starting pitchers on the year. He averages:
- Stuff+ and Predictive Stuff+: 101.5
- Command+: 108.3
- Performance Plus: 106.9
(All numbers that indicate being slightly above average, but over his last 10 starts, Griffin has made the case for being a second-half breakout star.)
The Arsenal Usage Adjustment:
- Starting with his Stuff+, Griffin has improved dramatically since his outing on June 5th, 2026, where he went 5 innings of 1-run ball.
- Since that start, Griffin has elevated his Stuff+ to sit around the 108–110 mark, which is about 8 points higher than his season average.
- This can be attributed not to a change in pitch shapes, but a change in arsenal usage. Over his last 3 games, Griffin has:
- 📉 Reduced his fastball usage from 18% to 15%.
- 📈 Boosted his curveball usage from 10% to 14%.
The Result: Ever since making this arsenal usage adjustment, Griffin has become the #3 ranked qualified MLB starter over the last 30 days, compared to being the #82 ranked starter for the time outside that span.
Do you guys think this level of performance is sustainable? Let me know down below, I'd love to have a conversation about it!
If you like these breakdowns and want more information like this, download Breakfast Baseball, an app that I made! (Coming to the App Store on July 14th)