The Cubs have played a LOT of games during their 146 seasons in the National League: 21,714, through Sunday.
Sunday's was their 16,514th since the beginning of 1916, the first season for which baseball-reference.com has comprehensive home run data.
After so many games, it is exceedingly rare to see something that NEVER has happened before. But that was the case on Sunday.
Rafael Ortega of the Cubs started the game at Washington with a home run.
Yadiel Hernandez of the Nationals ended it with a home run that defeated the Cubs, 6-5.
NEVER before had the Cubs hit a leadoff homer, then lost on a walk-off homer!
Ortega's homer was the 99th by a Cub as the first batter of the game since 1916.
Hernandez's homer was the 192nd walk-off against the Cubs since then.
3 IN REVERSE
The Cubs have won 3 games on walk-off homers that began with an opposing player homering.
The first of those took place Aug. 2, 1953 -- 1 day short of 68 years before Sunday's game.
Cal Abrams of the Pirates homered off Cubs pitcher Warren Hacker to begin the Sunday afternoon contest. Three singles produced another run later in the inning.
The Cubs pulled even in the third, on a 2-run, 2-out triple by Ralph Kiner, then took the lead on a pair of singles and a forceout in the fourth.
They added a run in the fifth, making their lead 4-2, but the Pirates scored 3 times in the seventh to move in front, 5-4, and knock out Hacker.
Kiner's 2 run homer in the bottom of the inning quickly put the Cubs ahead again, 6-5. The Pirates pulled even in the ninth, on a walk, a steal, a wild pitch and a 2-out single.
The Cubs went down in order in the ninth.
The Pirates stranded 2 and the Cubs 1 in the 10th.
The Pirates made 3 straight outs in the 11th. The first 2 Cubs were retired, too. Then Randy Jackson slammed his 15th homer of the season to give the Cubs a 7-6 victory.
LONG WAIT FOR NEXT TIME
The second such game was on May 21, 1987.
Tracy Jones of the Reds hit the leadoff homer, off Jamie Moyer.
Jerry Mumphrey tied the game with a 2-out homer in the Cubs' half of the first.
Moyer then surrendered a homer to the first batter in the second, and a 3-run shot in the third, putting the Cubs in a 5-1 hole.
They closed to within 5-4 when Shawon Dunston homered with 2 on and 2 out in the fourth.
A 2-out solo homer by Ryne Sandberg knotted the score at 5 in the fifth. All 10 runs in the game had come on 6 home runs.
That streak was snapped in the seventh. After Dunston led off with a double, Reds pitcher Ted Power threw wildly on a bunt by Dave Martinez, enabling Dunston to score and Martinez to reach second. Gary Matthews then singled home Martinez, making the score 7-5.
Cubs closer Lee Smith notched the first 2 outs in the ninth, only to allow back-to-back singles, then a game-tying double by Eric Davis.
The first 2 Cubs were retired in the bottom of the inning, bringing up Bob Dernier, who had pinch run for Matthews after his single in the seventh, then stayed in to play center field.
Dernier slammed a pitch by John Franco over the wall in center field for an 8-7 victory.
LAST OF ITS KIND
The Cubs' most recent game of the kind happened on Aug. 30, 1993, and it had an even more memorable finish.
Lenny Dykstra of the Phillies homered on the fifth pitch of the day by Cubs starter Frank Castillo. Three more hits, the last a run-scoring double by Darren Daulton, left the Cubs behind, 2-0.
But Phillies starter Curt Schilling was far from effective, either. Dwight Smith doubled and scored on a throwing error by the second baseman. Mark Grace's double tied the game, and 1 out later Sammy Sosa doubled home Grace.
The Cubs' 3-2 lead vanished in the fourth, when Castillo served up a single, a triple and back-to-back home runs, to John Kruk and Dave Hollins.
A single by Smith, a balk by Schilling and a single by Sandberg narrowed the Cubs' deficit to 6-4 in the fifth.
In the seventh, Sandberg greeted reliever David West with a single and raced home on a double by Grace. The next batter popped up, but with Sosa at the plate, West threw 2 straight wild pitches, allowing Grace to tally the tying run.
The Phillies left 2 on base in the ninth. The Cubs had 2 on with 1 out in the 10th, but grounded into a double play.
Roger Mason took over on the mound for the Phillies in the 11th. He struck out Willie Wilson and Sandberg.
Then Grace drew a 4-pitch walk, Derrick May beat out an infield hit and Sosa walked on a 3-2 count.
The count was 1-1 when Rick Wilkins walloped a ball to deep right field for a walk-off grand slam -- only the 10th such slam by a Cub until then.
They have hit 3 more since: by Alfonso Soriano, in 2009, and by Jason Heyward and David Bote, in 2018.
Of the 13 walk-off slams, 6 have come in extra innings and 7 in the ninth. Nine came with the score tied; 1 with the Cubs behind by a run; 2 when behind by 2 runs; and 3 when behind by 3: Bote's "Ultimate Slam" that beat the Nationals, 4-3, on Aug. 12, 2018, and Ellis Burton's that beat the Astros, 6-5, on Aug. 31, 1963.
CUBS' WALK-OFF HOMERS
The Cubs have hit 179 walk-off homers since 1901, most recently on July 16, 2019, when Kyle Schwarber broke a 3-3 tie against the Reds with a solo shot in the bottom of the 10th.
The Cubs had had 3 earlier walk-offs that season, matching their 4 in 2018. They also hit 4 in 8 other seasons, including 1953, when Jackson's was the third of the 4, and 2015.
They hit 5 in 1959, 1996, 2004.
Dernier's was their first of 3 in 1987. Wilkins' was their second of 3 in 1993.
Sammy Sosa hit the most walk-off homers as a Cub, 9. Ron Santo hit 6. Four players hit 5: Alex Gonzalez, Jim Hickman, Bill Nicholson and Billy Williams. Ernie Banks, Mark Grace, Aramis Ramirez and Anthony Rizzo hit 4.
Six players hit 3; 17, including Jackson, hit 2; and 76 hits 1, including Dernier and Wilkins, for a total of 109 different Cubs who have ended games with a home run.
OPPONENTS' WALK-OFF HOMERS
Opposing players have hit 192 walk-off homers against the Cubs since 1916. Unlike walk-offs by Cubs, I have not researched walk-offs against the Cubs in 1901-15; that would require examining the career Home Run Logs of every player on each of the 7 other National League teams who homered during those years!
Only 1 player has beaten the Cubs on a last-pitch home run 3 times: Bob Aspromonte, with the Colt .45s/Astros, who did it twice in 1963 and again in 1966.
Eleven players have turned the trick twice. Among them: Willie Mays, Willie McCovey, Stan Musial, Albert Pujols and Frank Thomas.
The 192 walk-offs were hit by 179 different batters.
CUBS' LEADOFF HOMERS
Ortega on Sunday became the 54th different Cub since 1916 to begin a game with a home run.
Nineteen had more than 1, led by Alfonso Soriano, with 12. Dexter Fowler hit 7; Brian McRae and Rick Monday, 5.
Five players hit 3 and 10 players hit 1.
Ortega's was the ninth such homer by a Cub against the Nationals, including their years as the Expos, in Montreal.
That is tied for their third most leadoff homers against any team. They also hit 8 against the Astros and Braves.
They have hit 12 against the Reds. The most recent was by Ian Happ on Aug. 29 of last season.
They have hit 11 against the Cardinals, most recently by Joc Pederson on May 21.
OPPONENTS' LEADOFF HOMERS
Opposing players have hit 103 leadoff homers against the Cubs since 1901.
They were hit by 89 batters, 4 of whom did it 3 times each: Craig Biggio, Davey Lopes, Heinie Sand and Rickie Weeks.
Don't recognize Sand's name? Neither did I. He was a shortstop for the Phillies in 1923-28 and hit a grand total of 18 home runs in 3,350 plate appearances. His leadoff homers against the Cubs all were among his career-best 6 homers in 1924.
Six players began 2 games vs. the Cubs with home runs: Ozzie Albies, Ray Blades, Barry Bonds, Lou Brock, Bill Doran and Zack Cozart.
Blades played outfield for the Cardinals in 1922-28 and 1930-32, hitting 50 homers in 2,846 PA. Both leadoff homers against the Cubs came in 1925.
Bill Doran was a second baseman for 3 teams in 1982-93. His homers came as an Astro, in 1984, off a pair of future Hall of Famers: Dennis Eckersley and Ferguson Jenkins. He hit 84 homers in 5,922 PA.
Your probably recognize the 4 others who hit 2 leadoff homers.
Bonds did it as a Pirate, in 1986 and 1987, the first coming off Scott Sanderson and the second off Greg Maddux. They were the 12th and 25th of his eventual 762 home runs.
Brock's were the 89th and 138th of his 149 career homers. He hit them off Jenkins, in 1968, and Rick Reuschel, in 1975.
Of the 10 who hit multiple leadoff homers against the Cubs, no fewer than 6 also hit a walk-off home run:
Brock, a solo homer off Ken Holtzman in 1969
Bonds, a 2-run homer off Jake Aker in 1973
Lopes, a grand slam off off Bruce Sutter in 1979
Doran, a solo homer off Chuck McElroy in 1991
But, of course, none of those games started with a Cub hitting a home run. No game ever did, until Sunday.