August 30, 1991 Mets pitcher David Cone throws an immaculate inning, striking out three Reds on nine pitches. Cone starts the bottom of the 5th inning and fans Herm Winningham, Randy Myers, and Mariano Duncan.
According to baseball-reference, an immaculate inning is defined as occurring when a pitcher strikes out all three batters he faces in one inning, using the minimum possible number of pitches – nine. The strikeouts can either be of the swinging or the caught looking variety, and there can be foul balls involved.
Immaculate innings were unheard of, back when striking out was considered the worse possible outcome of an at-bat. But they have increased in frequency as strikeouts became more acceptable as just another way of making an out. Especially with the rise of hard-throwing relief pitchers in the 1990s. Who come in for an inning, throwing gas. Immaculate innings, while still unusual, have become more common.
I believe that’s former Met Rusty Staub doing the play-by-play. This is the first year that Cone switched from uniform number 44 to 17, in honor of former teammate Keith Hernandez. Cone would go on to pitch 6 innings, striking out 9 and giving up 2 runs. The Mets won the game 3-2. Cone had been ineffective for much of the second half of the season, leading the Mets to fall out of the division race.
Related: Cone argues, while two runners score.
Only one other Mets pitcher has thrown an immaculate inning. Nolan Ryan was the first, back on April 19, 1968. In the third start of his career, Ryan faced the Dodgers at Shea Stadium. In the top of the third inning, Ryan struck out pitcher Claude Osteen, first baseman Wes Parker, and shortstop Zoilo Versalles. He took just 9 pitches, three for each of them.
The Mets have been victims of an immaculate inning three times. First on June 30, 1962, by Sandy Koufax of the Dodgers striking out Richie Ashburn, Rod Kanehl, and Felix Mantilla. Then on May 11, 1994, by Mel Rojas of the Montreal Expos retiring David Segui, Todd Hundley, and Jeff McKnight. Finally, on May 29, 2013, by Ivan Nova of the Yankees getting Ike Davis, Mike Baxter, and Ruben Tejada.