- Baseball
- Venue: Truist Park, Atlanta
- All times ET (New York)
Summary: Bryce Miller faces breakout rookie Hurston Waldrep at Truist Park in a pace-neutral, slightly homer-friendly park; bullpen form and late-inning leverage look like the swing factors.
About this preview
Written by Model-based Sports Desk — MLB matchup modeling, Statcast & bullpen usage. Reviewed by Senior Editor — Data QA & sources.
Published: • Updated: OverviewWeather / ConditionsLineupsMedicalTacticalKey FactsPlayer to WatchH2H & FormStatsAssessmentSensitivityFAQ
Match Overview
| League | MLB (Regular Season) |
|---|---|
| Season | 2025 |
| Date | September 6, 2025 • 7:15 PM ET |
| Venue | Truist Park (Atlanta, USA) |
| Officials | TBD (announced at first pitch) |
Source: MLB.com schedule; Probable pitchers
Source: Wikimedia Commons (open license)
Weather / Conditions
Evening conditions look playable: mid-70s °F (~24–26 °C), light wind, low precip risk. Truist Park is outdoor with no roof.
- Temp 24–26°C
- Precip 5–10%
- Wind 2–4 m/s
- Roof: Outdoor
Source: NWS Atlanta point forecast; SwishAnalytics MLB weather
Lineups & Environment
Atlanta Braves — Batting Order (projected)
- Core bats expected: Matt Olson, Ozzie Albies, Ronald Acuña Jr., Marcell Ozuna/Drake Baldwin (DH), Michael Harris II, Sean Murphy; recent addition Ha-Seong Kim at SS.
- SP: Hurston Waldrep • Bullpen core: Raisel Iglesias, Pierce Johnson, Tyler Kinley (usage varies).
Source: FanGraphs RosterResource; lineup note: Battery Power pregame
Seattle Mariners — Batting Order (projected)
- Core bats expected: Julio Rodríguez, Cal Raleigh, Jorge Polanco, Josh Naylor (recent trade), Eugenio Suárez, J.P. Crawford.
- SP: Bryce Miller • Bullpen core: Andrés Muñoz, Ryne Stanek, Gabe Speier.
Source: FanGraphs RosterResource; Naylor trade: MLB.com
Note: Replace “Projected” with “Official” once lineups are released (~60’ before start).
Medical & Condition
Atlanta Braves
- Out: Austin Riley (core surgery), Joe Jiménez (knee), Reynaldo López (shoulder)
- Doubtful/Questionable: Aaron Bummer (shoulder)
- Returning (reduced curve): Ha-Seong Kim (activated; recent back issue)
Source: MLB.com Injuries/Moves; Reuters
Seattle Mariners
- Out: Gregory Santos (knee), Jackson Kowar (shoulder)
- Doubtful/Questionable: Ryan Bliss (rehab)
- Returning (reduced curve): —
Source: MLB.com Injuries/Moves
Player & Tactical Analysis
Braves: Waldrep’s revamped mix (splitter + curve/cutter, reduced 4-seam) has driven a breakout — MLB sample ~35.2 IP with FIP ≈2.66 and whiff-heavy splitter (~45.7% whiff). Against a righty-tilted SEA core (Rodríguez/Raleigh/Suárez), Atlanta should lean splitter/curve below the zone and cutters in on RHH to cap damage.
Mariners: Miller’s fastball family (4-seam/sinker) has been hittable in 2025 relative to prior years; secondary usage (split/knuckle-curve) is the stabilizer. Braves profiles (Olson/Ozuna/Acuña) punish elevated heaters; Seattle likely emphasizes more split/curve and early count sinkers away to induce grounders.
Source: Waldrep: Baseball Savant, FanGraphs; Miller arsenal: Baseball Savant
Key Facts
- Probable pitchers: ATL Hurston Waldrep vs SEA Bryce Miller. (MLB.com)
- Park: Truist Park trends slightly friendly for singles (1B factor ≈103 in 2025); neutral overall power. (Baseball Savant)
- Recent bullpen form: Mariners pen trending better by FIP over last 14 days; Braves volatile. (FanGraphs article)
- All-time H2H: Mariners lead ~15–12; recent meetings split this series 1–1 entering Sat. (StatMuse/TheSportsDB)
Source: MLB.com; Savant venue factors; FanGraphs bullpen form; StatMuse H2H; TheSportsDB
Player to Watch
Atlanta Braves — Hurston Waldrep (SP)
Splitter whiff ≈45% with improved command; run prevention driven by K’s and weak air contact when he avoids elevated heaters.
Source: Baseball Savant
Seattle Mariners — Julio Rodríguez (CF)
Game-breaking power/speed and recent surge; if he wins the fastball battle early counts, Seattle’s win odds jump materially.
Source: FanGraphs team page
Head-to-Head & Form Context
Head-to-Head
| Last 5 meetings | Braves 2W–3L (incl. this series split entering Sat.) |
|---|---|
| All-time record | Mariners lead ≈15–12 (interleague) |
Source: StatMuse; recent results: TheSportsDB
Form & Momentum
| Atlanta Braves last 5 | W–L–L–W–L (mix of Cubs/Mariners) |
|---|---|
| Seattle Mariners last 5 | L–W–L–L–W |
Source: TheSportsDB results feed
Statistics & Simulations
| Probable pitchers | Hurston Waldrep (ATL) — FIP ~2.66; trending up • Bryce Miller (SEA) — 2025 ERA ~5.7, FIP ~4.5 (stabilizing) |
|---|---|
| Bullpen snapshot | ATL: volatile late/HI leverage • SEA: recent FIP improvement but variable run prevention |
| Park factor | Truist Park: 1B factor ≈103 (2025); near-neutral for HR overall |
| Win probability | Atlanta Braves 53% — Seattle Mariners 47% |
|---|---|
| Total runs (proj) | 8.2 (lean Slight Over 7.5 / neutral vs 8.0) |
| Likely scorelines | 5–4, 4–3, 5–3 (±1 run) |
Source: Pitcher stats — FanGraphs, FanGraphs; Park — Baseball Savant; Bullpen trend — FanGraphs
Final Assessment
Model-calibrated probabilities (sum ≈ 100%):
- Home win: 53%
- Draw/Tie (if applicable): 0%
- Away win: 47%
Key drivers: Waldrep splitter whiffs; Braves power vs elevated heaters; Mariners late-inning FIP uptick; neutral weather; Truist Park singles boost.
Sensitivity (Top-5 Drivers)
| Driver | Δ Impact | Notes |
|---|---|---|
| Waldrep splitter CSW% | Δ ±7–9% WP | CSW ≥32% tilts ATL; <26% swings SEA. |
| Miller heater locations | Δ ±6–8% WP | Heart-zone FB rate ↑ risks ATL HR; edge usage + split lowers EV. |
| High-leverage bullpen IP | Δ ±6% WP | SEA pen FIP trend strong; ATL variable in 7th–9th. |
| Weather (wind out ≥5 m/s) | Δ ±3% WP | Would push total + HR expectancy; current outlook calm. |
| Defensive efficiency | Δ ±3% WP | ATL infield with Kim stabilizes SS plays; SEA corner IF mix matters. |
Source: Model stress tests; stat baselines from FanGraphs/Savant linked above.
FAQ
What time is the game?
Scheduled for September 6, 2025 • 7:15 PM ET.
Will official lineups be added?
Yes — replace “Projected” with “Official” approximately 60 minutes before start once teams are confirmed.
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Informational purposes only. No guarantee of outcomes. Not financial advice. Trademarks belong to their respective owners.