Here's a stat that doesn't make any sense, no matter how many times you read it: Don Mattingly hit six grand slams in the 1987 season. He hit zero grand slams in every other season of his 14-year career. Six and never again. All of them -- every single bases-loaded home run Mattingly would ever hit in professional baseball -- came in one calendar year. It's the kind of statistical anomaly that makes sabermetricians scratch their heads and poets nod knowingly. Baseball doesn't always follow logic. Sometimes it just decides to concentrate a player's entire clutch-hitting destiny into a single season and walk away.
The Record
Before Mattingly's 1987 campaign, the single-season grand slam record had been held by several players with five. Mattingly didn't just break it -- he lapped it, hitting six in a season where he also tied the record for consecutive games with a home run. The slams came scattered across the schedule, with a cluster of three in September that turned the final month into a grand slam watch.
The record stood alone until Travis Hafner of the Cleveland Indians tied it in 2006, nearly two decades later. As of 2026, nobody has hit seven. Mattingly and Hafner share the mark, but the stories behind them couldn't be more different. Hafner's came during a long, productive career. Mattingly's were his only ones -- ever.
The Absurdity of Zero
The zero that follows is what elevates this from impressive to inexplicable. Mattingly played from 1982 through 1995. He accumulated 2,153 career hits, 222 home runs, and hundreds of plate appearances with the bases loaded. In every season except 1987, when the bases were full and Mattingly came to the plate, the ball stayed in the park. Every single time. Before '87 and after '87 -- nothing. Not one grand slam across 13 other major league seasons.
(It's worth sitting with that for a moment. A player who hit 30 home runs that season, who'd hit 35 the year before, who possessed one of the sweetest swings in baseball history -- and he could only hit grand slams during one specific calendar year. Baseball occasionally produces coincidences that defy any rational explanation. This is one of them.)
The Slams Themselves
The six grand slams came against a variety of opponents and in a variety of situations. Some came early in games, blowing things open. Others came late, providing insurance or sparking rallies. Two of them occurred during Mattingly's eight-game home run streak in July, adding an exclamation point to a stretch that was already the most dramatic individual performance of the season.
Three of the six came in September, when the Yankees were already fading out of the division race. By that point, Mattingly's grand slam total had become its own subplot -- fans tracked it the way they'd track a no-hitter through the middle innings, willing each bases-loaded at-bat to produce another historic blast. He obliged three more times, pushing the total to six and the record into the books.
Context Within the Season
Mattingly's full 1987 line -- .327, 30 home runs, 115 RBI -- was outstanding by any standard. It marked his fourth consecutive season with 100-plus RBI and his fourth straight year hitting above .310. The grand slams were the cherries on top of a season that also included the home run streak, a seventh-place MVP finish, and the quiet knowledge that his best years were running out.
The 1987 Yankees had plenty of offensive firepower beyond Mattingly. Mike Pagliarulo hit 32 homers. Rickey Henderson, Dave Winfield, Dan Pasqua, and Gary Ward all contributed 16-plus homers. The team hit 10 grand slams total -- the most in baseball that year -- with Mattingly responsible for 60 percent of them. The offense could mash. The pitching staff couldn't match it, and the team finished fourth.
Why It Happened (And Didn't Happen Again)
Nobody has satisfactorily explained why Mattingly's grand slam output was concentrated entirely in 1987. Some have pointed to the composition of the lineup -- runners getting on base ahead of him in specific ways that loaded the bases more frequently. Others have suggested it was simple variance, the baseball equivalent of rolling six sevens in a row at a craps table. The truth is probably a combination of both, seasoned with a dose of the unexplainable.
What we know is that Mattingly's swing didn't change before, during, or after 1987. He remained one of the most consistent hitters in the American League throughout the late 1980s. The grand slams didn't come because he altered his approach -- they came despite his approach remaining the same. The difference was circumstance, timing, and whatever invisible forces conspire to turn a routine at-bat into a bases-clearing blast.
| Grand Slams in 1987 | 6 (MLB single-season record) |
| Career Grand Slams | 6 (all in 1987) |
| Grand Slams in Other Seasons | 0 |
| Career Games Played | 1,785 (1982-1995) |
| 1987 Full Line | .327, 30 HR, 115 RBI |
| Record Tied By | Travis Hafner, 2006 |
| Team Grand Slams in 1987 | 10 (most in MLB) |
First Grand Slam
Mattingly connects on his first grand slam of the season, beginning a record-setting run that nobody -- including Mattingly -- saw coming.
Two Grand Slams During HR Streak
Two of Mattingly's six grand slams come during his eight-game home run streak, overlapping two of the most remarkable individual achievements of the decade.
Three Grand Slams in the Final Month
Mattingly hits three grand slams in September alone, pushing his total to six and setting the new single-season record.
Grand Slam Number Six
Mattingly's final grand slam of the season -- and, as it will turn out, of his entire career -- gives him sole possession of the MLB record.
The Zero That Followed
In the remaining eight years of his career, Mattingly never hits another grand slam. The anomaly remains one of baseball's great statistical mysteries.
Frequently Asked Questions
How many grand slams did Don Mattingly hit in 1987?
Mattingly hit six grand slams in 1987, setting a major-league single-season record. Travis Hafner tied the record in 2006 with the Cleveland Indians. No player has ever hit seven grand slams in a single season.
Did Mattingly hit grand slams in other seasons?
No. In what remains one of baseball's most baffling statistical anomalies, Mattingly's six grand slams in 1987 were the only grand slams of his entire 14-year career (1982-1995). He hit 222 career home runs but never connected with the bases loaded in any other season.
When was the grand slam record tied?
Travis Hafner of the Cleveland Indians tied Mattingly's record by hitting six grand slams during the 2006 season. The record has been shared since then, with no player reaching seven.