Historic MLB Moment September 21, 2001 Shea Stadium, Flushing NY Braves (2) @ Mets (3)

Mike Piazza 9/21/01 Shea Homer: Game-State & Win Probability Analyzer

The first major professional sporting event in NYC after September 11. Relive the dramatic 8th inning, scrub Steve Karsay's pitches, trace the 417-ft opposite-field blast, and witness the +0.49 WPA win-expectancy swing as testified by Todd Zeile in the on-deck circle.

🏟️ Shea Stadium 8th Inning Tracker
1-1 Count • 1 Out • Man on 1st
8TH INNING CHRONOLOGY SCRUBBER Step 3 of 4: Piazza 1-1 Pitch Contact
338 LF 371 410 CF 378 RCF 338 RF 9 Todd Zeile (On-Deck) 31 Mike Piazza 13 E. Alfonzo 417 FT (SHEA CAMERA WELL)
Game State
Braves 2, Mets 3
Estimated Distance
417 FT
Exit Velocity
107.5 MPH
Launch Angle
28°
⚙️ Statcast-Style Trajectory & Shea Stadium Wall Clearance Tester
Exit Velocity 107.5 mph
Launch Angle 28°
âś“ Clears 378 ft RCF Shea fence by ~39 feet into the center-field camera well
WIN PROBABILITY ADDED (WPA)
Leverage Index (LI): 3.18 (Extreme High Leverage)
+0.49 WPA
NYM 82%
ATL 18%
Pre-Pitch: Mets 33% (Trailing 2-1) Post-Swing: Mets 82% (Lead 3-2)

"It felt like it had to be Mike [Piazza], it almost felt like it was destined."

— Todd Zeile • Mets 1B (On-deck circle during Piazza’s 8th-inning AB)
Zeile was holding a 1-for-3 night at first base, watching Steve Karsay's 1-1 inner fastball before Piazza launched the ball deep into the Flushing night.
Official Box Score: Atlanta Braves at New York Mets (9/21/2001)
Team 123456789 RHE
Braves (83-68) 000000020 251
Mets (75-76) 00000003X 360
Key Participants in the 8th Inning
Player Role Game Line 8th Inning Impact
Mike Piazza Catcher (NYM #31) 1-for-4, HR, 2 RBI, R Go-ahead 2-run HR (417 ft to RCF)
Edgardo Alfonzo 3B (NYM #13) 0-for-2, 2 BB, R Drawn walk vs. Karsay with 1 out
Todd Zeile 1B (NYM #9) 1-for-3, 1 K Waiting on-deck, witnessed 417-ft flight
Steve Karsay RHP (ATL #34) 0.1 IP, 1 H, 2 ER, 1 BB Charged with blown save & loss (LP)
Armando Benitez Closer (NYM #49) 1.0 IP, 0 H, 0 ER, 2 K Pitched 9th inning to seal 3-2 victory (W)

Historical Significance & Shea Stadium Outfield Geometry

On September 21, 2001, ten days after the September 11 terrorist attacks, 41,235 fans packed Queens' Shea Stadium. Trailing 2-1 in the bottom of the 8th inning with one out and Edgardo Alfonzo on first base, Mike Piazza faced Atlanta reliever Steve Karsay on a 1-1 count. Piazza turned on a 94-mph fastball, sending it 417 feet over the 378-foot right-center wall and past the blue fence into the auxiliary television camera enclosure.

The home run caused a massive +0.49 WPA leap (Win Probability Added), instantly flipping the game from a 67% Atlanta win expectancy to an 82% New York Mets victory probability. Shea Stadium—notorious for deep power alleys (371 ft left-center, 378 ft right-center, and 410 ft dead center) and swirling winds from Flushing Bay—rarely yielded opposite-field home runs of that magnitude under extreme late-inning leverage.