For a pitcher to put together a lengthy streak of Opening Day starts, a lot of factors have to come together.

He must be good enough, over a long period of time, to earn the assignments. He must be durable enough to avoid even a minor injury at the wrong time. And he must be fortunate enough not to have a superstar teammate -- or even a highly respected veteran teammate -- to grab those starts away.

Add those ingredients together and some special things can happen. That is certainly true for the following pitchers who have authored the longest runs of consecutive Opening Day starts.

(All data is since 1904, the first season for which it is available.)

• Pitchers with the most Opening Day starts

1. Jack Morris -- 14 straight starts, 1980-93
Morris' 14 career Opening Day starts are tied for second-most in history, and not only did they come in consecutive years, but they also came with three teams. The right-hander got his first 11 with the Tigers, then followed that with one for the Twins and two for the Blue Jays. During that 14-year span, just four other pitchers started even half as many times on Opening Day.

Morris usually rose to the challenge, posting a career ERA of 3.39 in openers. He is one of only two pitchers -- along with Rick Mahler -- to record at least three complete-game victories on Opening Day since 1980.

2. (tie) Tom Seaver -- 12 straight starts, 1968-79
The all-time leader in total Opening Day starts (16), Seaver began his streak in 1968, the legendary Year of the Pitcher. At the time, the 23-year-old Tom Terrific was the reigning National League Rookie of the Year with the Mets.

After stringing together 10 consecutive openers with the Mets, Seaver was traded to the Reds midway through the 1977 season. He took the ball in Game 1 for Cincinnati in each of the next two seasons, but he gave way in '80, ending a streak that included four starts with no more than one run allowed.

2. (tie) Robin Roberts -- 12 straight starts, 1950-61
Roberts started one other Opening Day for the Astros in 1966, but his entire 12-season streak came with the Phillies. That makes him the record holder for the most consecutive openers by a pitcher with the same team.

The right-hander made six of his 13 career Opening Day starts against the Dodgers, including two that bookended his streak. As a 23-year-old in 1950, Roberts gave up just one run (scored by Jackie Robinson) in a complete-game win over Brooklyn. As a 34-year-old in '61, he was outdueled by Don Drysdale in Los Angeles. In between, Roberts started in the Dodgers' final Opening Day game before leaving New York, giving up seven runs in a complete-game 12-inning loss in '57.

4. (tie) Félix Hernández -- 10 straight starts, 2009-18
King Félix began his streak two days shy of his 23rd birthday in 2009. The righty held the Twins to one run over eight innings that day, on his way to his first All-Star selection. Hernández followed that up the next year by allowing three earned runs -- his career-high in an opener -- but Seattle still beat Oakland, and he went on to capture the American League Cy Young Award.

Overall on Opening Day, Hernández owns a sparkling 1.53 ERA and 0.77 WHIP. During his 10-year streak, Hernández allowed no more than one earned run six times, including a scoreless outing against the Indians to begin the 2018 season. That was the final start in his run, which ended when Marco Gonzales started the Mariners' 2019 opener against the A's in Japan.

4. (tie) Roy Halladay -- 10 straight starts, 2003-12
Coming off a breakout season in 2002, Doc toed the rubber in Toronto's first game of '03, and while he struggled that day, he went on to claim the first of his two Cy Young Awards. The Hall of Fame righty started seven consecutive openers for the Blue Jays, setting an overall club record.

Halladay added three more Opening Day starts to his streak after his trade to the Phillies in December 2009, and he was in dominant form. Over those three outings, he allowed just two runs in 21 innings, with a 20-to-2 strikeout-to-walk ratio. Facing the Pirates in 2012, Halladay allowed singles to his first two opponents, then retired 23 of his final 25, with the exception of two hit batters.

4. (tie) Steve Carlton -- 10 straight starts, 1977-86
The only thing standing in the way of Carlton putting together a record streak of 15 straight Opening Day starts, all with the Phillies, was the club acquiring Jim Kaat from the White Sox before the 1976 season. Even though Carlton did the honors in each of the previous four years, Philly went with the older lefty in Kaat, who was coming off a 20-win All-Star campaign.

However, Carlton outpitched Kaat and won 20 games in 1976, earning back the Opening Day nod the next year and holding onto it through '86, when he was released in June. During that 10-season stretch, Carlton captured the final three of his four NL Cy Young Awards, won 155 games and had a 3.13 ERA.

4. (tie) Walter Johnson -- 10 straight starts, 1912-21
Even considering that this was the Deadball Era, the Big Train was an unstoppable locomotive during most of this streak. From 1912-19, the Washington Senators star pitched 77 innings across eight Opening Day starts, or more than nine frames per outing. He gave up just 51 hits and seven earned runs for a 0.82 ERA.

The streak featured four shutouts and culminated with a 13-inning victory over the Philadelphia Athletics in 1919. That would be the longest shutout recorded in an Opening Day start -- except that Johnson beat his own mark seven years later by tossing 15 scoreless innings against the A's.

8. (tie) CC Sabathia -- 9 straight starts, 2006-14
Sabathia started his first two openers for the Indians in 2003-04, and after missing a year, he reeled off nine in a row. The streak began in Cleveland, then continued in New York, where Sabathia signed before the '09 season.

While Sabathia allowed just two runs in 14 innings over his first two Game 1 outings, he didn't fare nearly as well during the streak. Only once out of nine starts did the lefty give up fewer than three earned runs, and he posted a 7.58 ERA overall.

8. (tie) Randy Johnson -- 9 straight starts, 1998-2006
The Big Unit is tied for second with 14 total Opening Day assignments, but he might have put together 15 in a row beginning in 1992 if not for a back injury that cut short his '96 season. The Mariners didn't put Johnson on the mound to begin '97, when he went on to post the best ERA of his career (2.28).

Still, Johnson took the ball first in each of the next nine seasons, a streak that included his final year in Seattle, six in Arizona and two in New York with the Yankees. Over his final eight openers, the five-time Cy Young Award winner produced a 2.20 ERA and struck out 57. The last three of those occurred past his 40th birthday, making him one of five pitchers to start so many Opening Days at that age.

8. (tie) Dennis Martinez -- 9 straight starts, 1988-96
The Nicaragua native's first two openers came with the Orioles in 1982-83, but he didn't get another chance until after Baltimore traded him to Montreal in June '86. Following a strong season in '87 that resurrected his career, Martinez took the mound first for the Expos in each of the next six years, and he now ranks behind only Steve Rogers for the most openers started in club history. He made his final three Opening Day starts with the Indians.

Martinez's best Game 1 performance came against the Pirates in 1991, when Barry Bonds' seventh-inning single provided the only hit against him in seven scoreless frames. That performance foreshadowed what Martinez did later that season at Dodger Stadium on July 28, when he became the first pitcher born outside the U.S. to twirl a perfect game.

8. (tie) Bob Gibson -- 9 straight starts, 1967-75
The Cardinals great made his first and only other Opening Day start in 1965, succeeding Ernie Broglio, who had been traded to the Cubs the previous summer in what became a famous (or infamous) deal for Lou Brock. That first Game 1 outing didn't go well, but when Gibson got another chance, he didn't disappoint.

Gibson struck out 13 Giants in a shutout to begin the 1967 campaign, which ultimately ended with the Hall of Famer earning his second World Series MVP trophy by allowing just three runs over three complete-game wins against the Red Sox. The following year, he held the Braves without an earned run over seven innings, the first step toward his record 1.12 ERA. From 1967-72, Gibson posted a 1.49 mark over six openers, although St. Louis went just 3-3 in those games.