Texas Rangers outfielder Nelson Cruz is the breakout star of the postseason. (Paul Sancya/AP)

The thrilling American League Championship Series — stuffed with 100-mph fastballs, an 11th-inning grand slam, a decisive cameo by the third base bag and almost no pitches thrown without heart-pounding drama — will come down this weekend to the “simple math” described by Texas Rangers second baseman Ian Kinsler.

With one victory, the Rangers can reach the World Series for the second straight season and cement their status as baseball’s next powerhouse. With two straight wins, the Detroit Tigers can complete a legendary comeback with a bruised and resilient lineup. The winner will claim both the pennant and one of the most intensely competed playoff series in recent memory — “major league baseball at its best,” Tigers Manager Jim Leyland said.

While the Rangers have held control of the series since their Game 1 victory, the Tigers have had chances to win every game. The Rangers have outscored the Tigers by four runs, but without extra innings the Tigers have actually outscored the Rangers, 20-16, in the first five games.

Despite being down in the series, 3-2, the Tigers may hold the starting pitching advantage, with Max Scherzer facing Derek Holland in Game 6 and Doug Fister against Colby Lewis in a possible Game 7. The Tigers, judging by Bill James’s Game Score formula, have received better starting pitching performances in every game aside from Game 1, when a rain delay forced Justin Verlander and C.J. Wilson from the game early.

The pitching schedule puts the onus on the Rangers to finish off the Tigers on Saturday night. Some Texas officials believe Fister’s sinkerball, strike-throwing approach presents the Rangers’ lineup the stiffest challenge of any Tigers starter — Verlander included. Fister made the best start of any pitcher this series in Game 3, when he allowed two earned runs in 7 1 / 3 innings.

The reason the Rangers hold their lead, really, is Nelson Cruz, the breakout star of the postseason. He crushed a walk-off grand slam in Game 2 and a three-run homer in Game 4, both in the 11th inning. With perhaps two games left, Cruz has already set a championship series record with five home runs. His fifth came in Game 5, when he hit Justin Verlander’s 0-2, 100-mph fastball over the left field fence. It was the fastest pitch thrown in the majors all season hit for a home run.

“ ‘Wow’ is all you can say,” Rangers outfielder David Murphy said. “Just when you think you’ve seen everything, he goes and does something else. You’re trying to protect, not just with two strikes but 0-2, trying to battle your way back. And you hit a 100-mph fastball, and you turn on it like that? I mean, who else could do that?”

Leyland acknowledged the Tigers’ need to change their approach against Cruz, joking on a conference call with reporters, “If anybody has any suggestions, I’ll be willing to take it.”

Only 10 teams in baseball history have overcome a 3-1 deficit to win a seven-game series, and the Tigers are trying to become the first since the 2007 Boston Red Sox. Those Red Sox stunned the Cleveland Indians, which included 28-year-old catcher Victor Martinez. Now 32, Martinez is the Tigers’ designated hitter.

“I was on the other side in ’07,” Martinez said. “Never take anything for granted. Never. Never. Never take anything for granted. When you have the chance to finish off somebody, do it. We just keep playing, head down, keep swinging. We’ll see what happens.”

Because of Sunday’s postponed game , the Tigers and Rangers played four consecutive days, a rarity in October. The Rangers decided to work out on their off day, taking batting practice and some light fielding drills. The Tigers stayed away from the park.

Both teams, as any would be this time of year, are banged up. The Rangers’ Adrian Beltre fouled a ball hard off his left knee in Game 3, Josh Hamilton is playing through a groin strain and Cruz missed two weeks in September with a hamstring injury. Beltre and Hamilton skipped the Rangers’ workout Friday, which Manager Ron Washington called “optional.” (Third baseman Michael Young said he believed the workout was “mandatory.”)

The Tigers, though, likely benefit more from the day off. The Tigers’ top two relievers, Jose Valverde and Joaquin Benoit, were not available for Game 5, but both will be available with two days of rest Saturday. Delmon Young (oblique strain), Alex Avila (patellar tendinitis) and Martinez (rib cage muscle strain) also will receive an extra day to rest.

“I could not be prouder of my team,” Leyland said. “I don’t know that I’ve ever been prouder of a team than this one. The way they’re playing hurt and playing so hard, they’re playing their hearts out. Are they good enough? We’ll find out in a few days.”