The never-say-die Oakland Athletics have forced an improbable fifth and deciding game in their American League Division Series with the Detroit Tigers.
Having made full use of their home-field advantage, the A's now have the opportunity to advance to the ALCS.
Standing in their way is Tigers ace Justin Verlander and a Detroit team and rife with experience.
Here are five matchups to keep an eye on as we find out who will play on and who will go home.
*Statistics via baseball-reference.com
In the first game of the series, Parker effectively shut down the heart of Detroit's lineup—Miguel Cabrera, Prince Fielder and Delmon Young—in Detroit.
If the Tigers are going to beat Parker, these three hitters have to produce.
Parker certainly benefited from the friendly pitching confines of the O.co Coliseum in his rookie campaign, having an ERA nearly two runs lower at home than he did on the road—2.61 compared to 4.54.
After pitching a gem in Game 1, the battle-tested Parker holds a slight advantage. That being said, you can never count out proven All-Star talents like Cabrera and Fielder.
This is only Bob Melvin's fifth career playoff game, and he's matching wits with Jim Leyland, a guy that was managing in the playoffs while Melvin was still a player.
Leyland has shown that he knows when to press the right buttons, as the Tigers are the third franchise he has taken to the playoffs. Meanwhile, Melvin and the Athletics have been on a roll coming down the stretch.
The winner tonight will be based in part on how much the manager trusts his players when the game is on the line.
Will Leyland stick with Verlander longer than normal based on his bullpen's poor performance? Will Melvin be too quick to pull Parker and rely on his late-inning arms?
How much does the pressure of a true elimination game change how these two normally manage, and who will make the mistake that decides the series?
Anytime you find yourself in a playoff clincher against the other team's ace, you are in a hole from the start.
In Game 1, Oakland got on the board first and made Verlander throw 60-plus pitches in the first three innings, before he pulled a classic Verlander performance and grew stronger as the game went on.
Tonight, the A's need to force Verlander to throw strikes early and lay off anything outside the strike zone. They also have to jump on him early enough to score the first time through the lineup.
Verlander and catcher Alex Avila adjusted the second time through the lineup on Saturday; his pitch locations were much better the second and third times he faced Oakland hitters.
If the A's can get into the bullpen early, they win this game. If Verlander is dealing early, they have no chance.
While the Tigers' starters have pitched very well, the bullpen is the reason there will be a Game 5 tonight.
After nearly coughing up Game 2, and Jose Valverde's meltdown last night in Game 4, the Tigers' relievers need a stand-and-deliver performance once they get the call, as Oakland hitters know they have the Tigers' number.
One of the toughest jobs in sports is to come back the next night after a horrific loss and simply do your job.
We saw Jim Johnson do it for the Baltimore Orioles Monday night against the Yankees, and Tiger fans will need to see Valverde do the same thing tonight for Detroit if called upon.
The Detroit pitchers face more pressure than anyone else going into tonight.
Oakland has to feel pretty giddy about that.
Despite a home run last night, the Detroit Tigers did not bring over Prince Fielder from the Milwaukee Brewers to hit just .188 in the postseason.
While Miguel Cabrera has had a good series, Fielder needs to show the Tigers, and himself, that he is ready to carry the load and help bring the Tigers to the World Series.
Perhaps that homer last night snapped him out of his untimely funk and he will deliver a performance for the ages, but no matter how good Justin Verlander, the bullpen or Cabrera are, the big man has to contribute and has to produce runs.
One of the big advantages Fielder and the Tigers had going in was playoff experience, while this was new to most of the Athletics—especially their starting pitching.
Now four full games into it, it is Oakland that has felt the most comfortable, winning the last two at home while Detroit tries to find their second gear.
If Fielder does not drive in a run, Oakland advances. They cannot rely on Alex Avila and the rest of the bottom of the lineup to carry them.
It is on Prince.
Elimination games are all about expectations.
The Oakland Athletics have played the better half of the season with nothing to lose and carried themselves to a good chance to advance tonight.
Meanwhile, no less than the entire world (and perhaps the dark side of the moon) were expected for the Tigers this year, and they barely won their division and dropped a two-game lead to the Athletics in this series.
They have the best pitcher in baseball taking the mound in a winner-take-all game. Verlander can completely shut any team down.
On the other hand, Oakland knows that they can wait out Verlander and attack the depleted Detroit bullpen.
If they can get on base early, they can distract Verlander into making a bad throw to first and shake everyone's confidence.
Oakland 5-3 and they advance