The history of the American League cannot be told without mention of two of its oldest franchises, the A's and the Yankees. The clubs have battled nearly 2,000 times in regular-season play and have staged three more series under the bright October lights, and now they're poised to square off once again in Wednesday's winner-take-all AL Wild Card Game.
More than 100 years of shared history have created plenty of connections for New York and Oakland. Before they take the field with aspirations of claiming this year's World Series crown, here are some of the prominent crossroads between the franchises in years prior.
MOMENTS
"The flip"
Whether it's a dream or a nightmare is in the eye of the beholder, but Yankees and Athletics fans can probably both recite Derek Jeter's famous play. It was Oct. 13, 2001, and the A's had a 2-0 lead in the ALDS when Terrence Long smacked a Mike Mussina pitch down the right-field line. Shane Spencer wildly overthrew both cutoff men, but Jeter -- as he seemed to be throughout his career -- was in the right place at the right time to pull off baseball's most famous improvisational play.

Jeter's "flip" preserved the Yankees' 1-0 lead in Game 3 and completely flipped the series. New York went on to the World Series, losing to Arizona in a thrilling seven-game set.
"The wave"
You've seen "the wave" pulsate through crowds at every Major League ballpark, but you might not know that the phenomenon traces its roots -- at least in part -- back to the AL Championship Series matchup between these clubs in 1981. Superfan "Krazy George" Henderson first brought the celebration to NHL games in the late 1970s, but its first televised appearance came in Game 3 of the Yankees-A's matchup on Oct. 15, 1981, at the Oakland Coliseum. The Yanks finished their sweep that night before going on to lose to the Dodgers in the World Series.
The K.C.-New York shuttle, 1950s
For many years, the most famous connection between these teams were the many future stars who began their careers with the Kansas City Athletics before winding up in the Bronx. It began when Arnold Johnson, a longtime Yankees business associate, sold his share in Yankee Stadium before buying the A's and moving them from Philadelphia to K.C. in 1954. For the next six years, a number of budding A's, including Clete Boyer, Art Ditmar, Enos Slaughter and Bobby Shantz (a 24-game winner for Philadelphia in '52) found themselves packing their bags for New York. The Yanks won five pennants in a span of six years to close out the decade, while the Athletics routinely languished in the AL cellar.
PLAYERS AND MANAGERS

Rickey Henderson
The Man of Steal shuffled back and forth between these two teams in the 1980s, stealing a combined 871 bases for them from 1979-89 while building one of the game's best all-around resumes. The Yankees traded five players to acquire Henderson and Bert Bradley from the A's in December 1984, and then the A's traded three players to get Henderson back five years later (right-handed pitcher Eric Plunk was involved in both deals). Henderson collected his most famous steal -- his 939th to pass Lou Brock for the all-time record -- against the Yankees on May 1, 1991.
Reggie Jackson
Jackson was the straw that stirred the drink for both the A's (beginning with his selection as the franchise's No. 2 overall pick in 1966) and the Yankees, proving integral to both teams' dynastic runs in the '70s. The slugger earned World Series MVP honors in '73 after knocking crucial hits in Games 6 and 7, and then earned his famous "Mr. October" moniker and a second Series MVP by hitting a record five homers for the Yanks in '77. All told, Jackson contributed to five World Series champions and hit a combined 398 home runs for the A's and Yankees.

Bartolo Colon
The man they call Big Sexy has now suited up for 11 Major League clubs, but his late-career renaissance began with back-to-back stints in New York and Oakland. Colon missed the 2011 season with lingering shoulder and elbow pain before signing a Minor League deal with the Yankees, with whom he went 8-10 with a 4.00 ERA. He parlayed that into a new contract with the A's in '12, starting a two-year run in which he went 28-15 with a 2.99 ERA and placed sixth in the '13 AL Cy Young Award vote.
Billy Martin
In between Martin's five roller-coaster stints as Yankees manager (which included a World Series title in 1977) was a three-year tenure as the A's skipper from 1980-82. Oakland adopted the aggressive "Billyball" style during that time, and he was widely credited in helping Henderson develop into the game's greatest basestealer. The A's started 18-3 to begin the '81 campaign, eventually rolling into the ALCS, where they lost to Martin's former (and future) club in three games.
Catfish Hunter
Like Jackson, it's hard to imagine the A's and Yankees winning their 1970s World Series titles without Hunter taking the ball in the biggest moments. Hunter tossed a perfect game for the A's in '68 and then posted four straight 20-win seasons from '71-74 while also going 4-0 in World Series play for Oakland across their three consecutive titles.
Hunter was declared a free agent (one of the game's first) after claiming the 1974 AL Cy Young Award, and signed a lucrative five-year deal with the Yankees. New York won three more pennants -- and two World Series -- with the righty in tow before diabetes forced Hunter into early retirement in 1979.

Roger Maris and Don Larsen
One of the last -- and perhaps most impactful -- of the A's series of deals with the Yankees came on Dec. 11, 1959, when Kansas City sent their 25-year-old All-Star Maris with two other players to the pinstripes in exchange for four players, including Hank Bauer and Larsen. Yanks fans know the rest: Maris immediately claimed back-to-back AL MVP Awards and broke Babe Ruth's single-season home run record in '61, and ultimately contributed to five straight pennant winners from '60-64. Larsen's best years were behind him, and he was already out of Kansas City by the time Maris passed the Babe at the end of '61.
Jason Giambi
Giambi blossomed into an offensive force with the A's, posting three straight seasons with 30 homers and 100 RBIs with Oakland from 1999-2001 and claiming the 2000 AL MVP before signing a free-agent deal with the Yankees. Expectations were high upon The Giambino's arrival in the Bronx, and he earned three more All-Star selections and led the AL in walks twice while knocking 209 total homers in pinstripes. Giambi would return for a second stint with the A's in 2009.
Johnny Damon
Damon logged one year in Oakland before signing a fateful free-agent deal with the Red Sox, with whom he became a postseason hero in 2004. His subsequent signing with the Yanks ranks among the most polarizing in recent memory, as Red Sox fans were forced to watch Damon help the Bronx Bombers to a World Series title in '09.
Eric Chavez
Chavez defined third-base defense while claiming six straight Gold Glove Awards in green and yellow, and he became a cornerstone of the "Moneyball" A's who defied expectations in the early 2000s. Chavez signed a Minor League deal with the Yankees in 2011, serving as a competent backup for Alex Rodriguez at third base for two seasons.
Goose Gossage
Gossage made his hay fireballing for the Yankees, of course, compiling three top-five Cy Young Award finishes during his dominant five-year tenure in the Bronx. But Gossage also donned an Oakland uniform during the first two seasons of his 40s, helping Tony La Russa's club reach the ALCS in 1992.
Scott Brosius
Yankees fans weren't quite sure what they were getting when they acquired Brosius as part of a deal involving Kenny Rogers in November 1997. As it turns out, what they got was a tremendous reclamation project. Brosius' .203 average with the A's ranked as baseball's worst among qualified hitters in '97, but by the end of the following season Brosius was hitting two homers in Game 3 of the World Series -- including a clutch two-run shot off Padres closer Trevor Hoffman. Brosius proved clutch again three years later when, with the Yanks down to their final out in Game 5 of the Fall Classic, he hit a game-tying home run against Arizona that sent Yankee Stadium into pandemonium.

Tommy John
A foundational figure in sports medicine, John recovered from reconstructive elbow surgery in 1975 to pitch three seasons for the Dodgers before signing with the Yankees in '78. John posted back-to-back 20-win seasons for New York in 1979-80, spending parts of four seasons in the Bronx before heading west to the Angels. He also logged half a season with the A's in '85 before going back to the Yanks for his final four seasons.
Home Run Baker
Before the Bambino, there was Baker, who was a member of the Connie Mack's famous "$100,000 infield" with the Philadelphia A's while leading the club to three World Series titles in the 1910s. Baker paced the AL in homers in four straight years from '11-14 (peaking at 12(!) in '13) before later teaming with Ruth on two pennant-winning Yankees teams in 1921 and '22. The Veterans Committee elected Baker to the Hall of Fame in '55.
Felipe and Matty Alou
Neither brother stayed with these teams for very long, but their paths did intersect for a brief moment in 1973. The Alous donned pinstripes together throughout the season until both were sent to NL clubs (Felipe to the Expos, Matty to the Cardinals) that September.
Sonny Gray
Gray's story in the Bronx still has chapters remaining, but the right-hander was dominant at times during his tenure in Oakland. Gray broke out in 2014, going 14-10 with a 3.08 ERA and helping the A's to the AL Wild Card Game, and finished up with an even better campaign (14-7, 2.73) to place third in the AL Cy Young Award voting the following year.