Six games into the 2026 Major League Baseball season, the Los Angeles Dodgers and Baltimore Orioles share the sport’s best record at 5-1, while two preseason favorites — the Houston Astros and New York Mets — have opened with stumbles that have already prompted bullpen reshuffles and pointed questions in clubhouses.

The Dodgers’ fast start, capped by a 7-2 home win over the San Francisco Giants on Tuesday night, has been built on a rotation that has yielded just nine earned runs across the first turn. Right-hander Tyler Glasnow struck out 11 in the opener at Dodger Stadium, and offseason acquisition Sota Murakami, the Japanese third baseman signed to a six-year, $148 million deal in December, is hitting .435 with three home runs through his first 23 at-bats in the majors.

“It’s a small window, but the quality of his swing decisions is already what we hoped we’d see in June,” Dodgers manager Dave Roberts said after Tuesday’s game. “He’s not pressing. He’s not trying to do too much. That’s the part that’s hardest for any player coming over.”

Murakami, who turns 26 next month, has drawn the loudest crowd reactions of the early Los Angeles homestand. His three-run shot off Giants reliever Camilo Doval on Sunday afternoon traveled an estimated 437 feet and prompted a four-minute curtain call. Roberts said the team plans to slow-walk Murakami’s exposure to left-handed pitching for the first three weeks, but the early returns have made that plan harder to enforce.

In Baltimore, the Orioles’ 5-1 mark has come against tougher early-schedule competition, including a season-opening sweep of the Boston Red Sox at Camden Yards. Catcher Adley Rutschman is hitting .368 with two home runs, and 22-year-old right-hander Cade Povich, making his first full-season rotation appearance, threw seven shutout innings against the Toronto Blue Jays on Monday.

“We didn’t talk about starts last week, and we won’t talk about them this week,” manager Brandon Hyde said. “What I will say is that the at-bats look like the at-bats we wanted in spring training. That’s the only piece you can really judge this early.”

The Orioles’ rotation, a frequent question mark in 2025, has produced a 2.41 ERA through six games. General manager Mike Elias’s offseason trade for left-hander Jesús Luzardo, sent from Miami in December for two prospects, has so far paid an immediate dividend: Luzardo struck out nine over six innings in his Baltimore debut on Saturday.

Not every contender has found the early rhythm. The Astros, picked by most preseason analysts to win the American League West for a ninth consecutive year, dropped four of their first five, including a stunning 13-2 loss to the Texas Rangers on Sunday in which Houston used six relievers. Manager Joe Espada acknowledged after the game that the bullpen plan “did not survive contact” with the Rangers’ lineup, and the club moved right-hander Bryan Abreu into a stricter setup role beginning Tuesday.

The Mets, meanwhile, opened 1-4 and have already lost shortstop Francisco Lindor to a strained left oblique. Lindor, hurt swinging in the seventh inning of Saturday’s home game against the Washington Nationals, is expected to miss at least three weeks, the club said in a statement Monday afternoon. New York manager Carlos Mendoza called the timing “frustrating” but said the team would not rush a return.

“You don’t get the season back by trying to make up two weeks in two days,” Mendoza said. “We’ve been through this with him before. The smart play is the boring play.”

Two other early storylines have caught the attention of front offices around the league. Pittsburgh’s Paul Skenes, the 2024 National League Rookie of the Year, has opened with two starts of 12 strikeouts each and an average four-seam fastball velocity of 99.4 mph, slightly above his 2025 mark. And in Detroit, Tigers center fielder Parker Meadows is hitting .429 with a 1.180 OPS after the team’s 4-2 opening week — a hot start that has the small-market club drawing comparisons, perhaps prematurely, to its 2024 playoff run.

The sport’s introduction of a new replay-challenge system for ball-and-strike calls, approved by owners in November and rolled out league-wide for 2026, has so far worked roughly as designed. Through the first 90 games of the regular season, teams have used their two-per-game challenges at a 38 percent overturn rate, according to data released by the commissioner’s office Tuesday. Average game length has crept up by an estimated 90 seconds compared with the same point in 2025, an increase Commissioner Rob Manfred called “within the band we projected and acceptable for the trade-off in accuracy.”

The competition committee will review the system again in late May, after a larger sample. Several player representatives have privately raised concerns about the rate at which catchers, rather than pitchers or hitters, are initiating challenges — a pattern, one veteran American League catcher said, that could create incentives to “shape” framing differently than in years past.

For now, with the first week concluded and the second under way, the early standings are more curiosity than verdict. The Dodgers travel to Philadelphia this weekend for a four-game series that will offer a tougher measure of the rotation’s depth, while the Orioles open a three-game home set against the New York Yankees on Friday. Espada said the Astros would convene a hitters’ meeting before Wednesday’s game in Arlington, and team officials said additional roster moves were being weighed before the team returns home next week.