Whether the Oakland Athletics get another chance to celebrate like this could depend on how Sean Doolittle, right, fares against Kansas City left fielder Alex Gordon. (LM Otero/AP Photo)

Major League Baseball’s wild-card games are just three years old, but we do know, though, two things: The starting pitchers could completely define the experience, and in a one-game win-or-go-home situation, late-inning matchups will be at a premium. Here’s a look at the potentially defining matchups of Tuesday night’s American League game.

AL Wild Card: Oakland Athletics vs. Kansas City Royals

THE STARTERS

Jon Lester (16-11, 2.46 ERA overall; 6-4, 2.35 ERA since trade to Oakland)
vs.
James Shields (14-8, 3.21 ERA)

Lester started and won the only two games the Athletics took from the Royals in the seven-game series this year, and he also threw 7-1/3 shutout innings against them as a member of the Red Sox, making him 3-0 with a 2.61 ERA against Kansas City, which he held to a .635 OPS. Shields, who just completed his eighth straight season with at least 200 inning pitched, threw twice against the A’s, posting a 3.21 ERA, and Kansas City won both times.

ROYALS RELIEVERS

Kansas City’s Wade Davis vs. Oakland’s Josh Donaldson

Greg Holland is the Royals’ closer, but the reason Kansas City advanced to the postseason for the first time since 1985 – breaking baseball’s longest drought – is they completely shorten games. Holland (1.44 ERA, 12.99 strikeout-to-walk ratio), eighth-inning man Wade Davis (1.00 ERA, 13.63 strikeout-to-walk ratio) and seventh-inning stud Kelvin Herrera (1.41 ERA, 7.59 strikeout-to-walk ratio) can all pitch out of jams with swing-and-miss stuff.

Davis, though, might be the key. He throws hard enough (an average fastball velocity of 95.6 mph, according to PitchF/x) that hitters can swing through his fastball, and he mixes in two other legitimate pitches – a cut fastball and a knuckle curve. Davis doesn’t just use those pitches as a change of pace; he uses them almost 40 percent of the time. (The breakdown: fastball 61 percent, cutter 20 percent, curveball 19 percent.)

This is important, because Donaldson is disciplined enough to lay off stuff that’s out of the zone, and he’s an excellent fastball hitter. Oakland’s third baseman has shouldered more of the offensive burden since the July 31 trade for Lester sent outfielder Yoenis Cespedes to Boston. After a sizzling August (.917 OPS), Donaldson joined the rest of Oakland’s slumping lineup in a lackluster September, when his OPS fell to .686. He has five career at-bats against Davis – a small sample size in which he’s has a double and two strikeouts. But it will be fascinating to see how Davis would pitch to Donaldson in a tight, eighth-inning spot. Does he start with his above-average fastball, which PitchF/x shows Donaldson hits far above average? Or does he begin the at-bat off-speed, throwing strikes with either his cutter or knuckle curve to put Donaldson in a hole?

ATHLETICS RELIEVERS

Oakland’s Sean Doolittle vs. Kansas City’s Alex Gordon

Doolittle, a lefty, inherited Oakland’s closer role when Jim Johnson imploded to start the season, and he returned to action Sept. 13 from a rib injury that cost him three weeks. His numbers (22 saves, 2.73 ERA) are skewed by a terrible outing Sept. 17 against Texas in which he gave up five runs in 1/3 of an inning. His ERA in his other 60 appearances was 2.02, and he has 89 strikeouts and just eight walks in his 62-2/3 innings. From late April to late June, he went 24 appearances – 26-1/3 innings – without allowing a run.

Doolittle does almost all of his work with his four-seam fastball, which averages 94 mph and he throws nearly 88 percent of the time. His secondary pitches, then, are truly secondary: a slider which he mixes in 11 percent of the time, and a scarcely used changeup. He is murder on left-handed hitters, which have a .118/.118/.158 slash line against him – no walks, no homers and just three doubles against him in 77 plate appearances.

Gordon is the most significant power threat in the Royals’ lineup – which, given they hit just 95 homers, the fewest in baseball, is faint praise. PitchF/x shows he’s an excellent fastball hitter, but he also holds his own against breaking and off-speed stuff. Though he is 0 for 3 against Doolittle in his career, he is as big a threat against lefties as he is right-handers – a .782 OPS with 11 homers against right-handers this year, a .787 OPS with eight homers against lefties.

Gordon, too, owns numbers that show he might be better in the biggest spots. As measured by baseball-reference.com, in “high-leverage” situations – plays when a dramatic change in win probability is highest – Gordon’s slash line improves to .337/.440/.584. Without a doubt, he’s the man the Royals want up in such a spot. If it comes Tuesday, it’ll likely be against Doolittle.