BALTIMORE — Jarrod Dyson got a new haircut for the postseason. Dyson, the Kansas City Royals’ speedy reserve outfielder, had the outline of a four-letter word, in all capitals, buzzed just above his right ear: ZOOM, it says.

 “That’s what I’m going to do tomorrow,” Dyson said at Camden Yards on Thursday.

 He is probably not kidding. The Royals had the most stolen bases in the major leagues this season. The Baltimore Orioles, their opponent in the American League Championship Series, had the fewest. The Orioles, however, hit the most home runs in the majors. The Royals — you guessed it — hit the fewest.

Contrasts don’t get starker than that, but these franchises have one big thing in common: a decades-long yearning for a championship. The Royals have the most losses in the A.L. since 2000, and the Orioles have the second most. Both have built patiently for this moment, for a chance at their first World Series appearance since the 1980s.

Mike Moustakas, right, and Lorenzo Cain of the Royals, who led the major leagues in stolen bases.

While the National League Championship Series features the familiar St. Louis Cardinals and San Francisco Giants — who have combined to win the last four N.L. pennants — the Orioles have not reached the World Series since 1983, and the Royals since 1985.

“I think it’s great for baseball, just because you get some new teams in there, and you see the excitement in the crowds,” the Royals’ Billy Butler said. “I think fans all around baseball are excited to see some new teams.”

Both teams swept their division series, the Royals over the Los Angeles Angels, who led the majors in victories and runs, and the Orioles over the Detroit Tigers, who started three former Cy Young Award winners.

The Royals hit only .198 against the Angels but found their power when they most needed it, with two homers apiece from Eric Hosmer and Mike Moustakas. Each hit a go-ahead, 11th-inning home run on the road against the Angels and another homer in the Game 3 clincher at Kauffman Stadium.

The Orioles agreed to a three-year contract extension with J.J. Hardy, a top fielding and home-run-hitting shortstop.

Anything can happen in a short series, of course, and perhaps the Royals will take advantage of the cozy dimensions at Camden Yards and hit more home runs. Whether or not that happens, though, they know they will run.

“That’s our game plan; that’s the strength of our ball club,” Hosmer said. “Teams know what we’re going to do. They know we’re going to steal. They know we’re aggressive, and it takes a perfect throw to get our guys.”

With Matt Wieters lost to Tommy John surgery, that task falls to the Orioles’ catching tandem of Nick Hundley and Caleb Joseph, a rookie who caught 40 percent of potential base stealers, the best mark in the A.L. Hundley is likely to catch Game 1 for Chris Tillman, who has allowed just two stolen bases the last two seasons, and Joseph said the Orioles’ pitchers are quick to the plate, whatever they throw.

“They’ve done such a good job at their times being fairly consistent with both the fastball and off-speed pitches, so there’s not a huge variation,” Joseph said. “Most guys start getting slower times with the off-speed pitches, but our guys are really close. So you’re not as pressured to call fastballs. Ultimately, if you continue to get the hitter out, then it doesn’t matter how many times he steals.”

Thanks to late-inning relievers including Kelvin Herrera, the Royals are the second team (after the 1907 Cubs) with three pitchers with at least 60 innings and an E.R.A. lower than 1.50.

 The Orioles’ pitchers had the A.L.’s third-best E.R.A. this season, at 3.44, and the staff got even better on July 31 with a trade for the left-handed reliever Andrew Miller. In 231/3 innings for Baltimore, including the postseason, Miller has 37 strikeouts and a 1.16 E.R.A.

Manager Buck Showalter deployed Miller twice in the division series, each times for five outs, and tends to be more unpredictable in bullpen usage, responding to the moment rather than adhering to strict roles. Ned Yost, the Royals’ manager, tends to manage more traditionally, offering another contrast in a series with many of them — against a common backdrop.

“Both franchises are starving for a winner,” the Orioles’ Adam Jones said. “We’ve got two franchises that haven’t been in that limelight. Now they’re in it. Let’s see what can happen.”

EXTENSION FOR HARDY The Orioles took shortstop J. J. Hardy off the free-agent market Thursday by reaching a three-year contract extension, widely reported to be worth $40 million, with an option for 2018. Hardy, who could have been an option for the Yankees as they seek a replacement for Derek Jeter, has hit 86 homers in the last four seasons, most among major league shortstops, while winning two Gold Gloves.

Moe Drabowsky, pictured in the 1966 World Series, pitched for both Baltimore and Kansas City.

HISTORIC DOMINANCE The Royals’ late-inning bullpen triumvirate of Kelvin Herrera, Wade Davis and Greg Holland was overwhelmingly effective this season, each with an earned run average below 1.50. According to Baseball Prospectus, the Royals are only the second team to have three pitchers with at least 60 innings and an E.R.A. under 1.50. The other? The 1907 Chicago Cubs, who used just eight pitchers all season and had little use for a bullpen, tossing 114 complete games.

DAVIS MUST WAIT The Orioles’ Chris Davis is featured prominently in a billboard above the center-field seats at Camden Yards, but that is the only place fans may find him in the A.L.C.S. Davis’s 25-game suspension for taking Adderall without a therapeutic-use exemption is set to expire after the first five games of this series, but the Orioles did not put him on their active roster. Buck Showalter said they did not want to play with a 24-man roster until Davis returned. Davis, an All-Star first baseman last season who now plays third, took grounders and batting practice during Thursday’s workout.

NEW DADS Two of the more important players in the A.L.C.S. have been busy since their teams clinched the division series. Orioles closer Zach Britton took a red-eye from California, arriving here Thursday after the birth of his son, Zander. Royals center fielder Lorenzo Cain flew in from Oklahoma City after the birth of his son, Cameron. “I was crying like a big baby,” Cain said. “I’m glad I was able to make it.”

GOOD COMPANY Nelson Cruz and Frank Robinson both have 149 career plate appearances in the postseason. Cruz, the Orioles’ designated hitter, has 16 home runs, and Robinson, the Orioles’ Hall of Famer, had 10. Robinson had a .532 slugging percentage in the postseason, almost identical to his regular-season mark. Cruz’s career postseason slugging percentage is .710, more than 200 points above his regular-season figure.

SPENDING IN MODERATION The Orioles ranked 15th in the majors in opening-day payroll, at roughly $107 million, while the Royals ranked 19th, at about $92 million. Baltimore’s franchise record is a six-year, $85.5 million contract for outfielder Adam Jones, who is signed through 2018. The Royals’ record guarantee is $55 million, for outfielder Mike Sweeney after the 2002 season and for pitcher Gil Meche, who retired before he could finish the deal in 2011.

COMMON ALUMNI Moe Drabowsky was the winning pitcher in the Orioles’ first World Series game in 1966, blanking the Dodgers for six and two-thirds innings in relief. Three years later, on April 8, 1969, Drabowsky won the first game in the history of the Royals, working a scoreless 12th inning in a 4-3 victory over Minnesota. That game was started by another expansion draft choice, Wally Bunker — another Orioles hero in that 1966 World Series. Bunker pitched a shutout in Game 3, the first World Series game held in Baltimore. The first batter in Royals’ history, Lou Piniella (he doubled), started his career with four games for the Orioles in 1964. Other notables to play for both teams include Mike Boddicker, who earned the Orioles’ first victory in the 1983 World Series; Gregg Olson, who won the 1989 A.L. Rookie of the Year award as the Orioles’ closer; and Royals starter Jeremy Guthrie, who pitched five seasons for Baltimore, twice leading the league in losses.

PLAYOFF HISTORY The Orioles or the Royals played in the A.L.C.S. 10 times in 13 seasons from 1973 to 1985, the years of Jim Palmer, George Brett and other colorful stars. Yet not once did the teams meet for the pennant. That changes on Friday at 8 p.m. at Camden Yards.