Red Sox power rankings: Which player is most responsible for the success of Alex Cora’s inaugural season?

The defense held Seattle to a field goal on its second scoring drive Friday night, before a brilliant pitching performance shut down the opposition entirely on Sunday, giving the Red Sox a win in their weekend series with the Mariners – and putting Boston in a tie for the major-league lead in wins, with 52.

Houston has the same, followed by the Yankees’ 50, though after that there was no club in baseball within five of the Sox and Astros entering Monday. What’s impressive about Boston’s run, too, is that it’s not entirely built upon the back of a 17-2 start. In their first 40 games, the Sox were 28-12; with a win Tuesday against the Angels they’ll have gone 25-15 in the next 40. That’s better than .600 ball in each quarter-season split.

Here’s a look at which players are most responsible for the successes of Alex Cora’s inaugural season, with the Red Sox power rankings through 79 games:

30. Jalen Beeks – Chances are good that the Sox will need another start from their minor-league system at some point this season, and the 24-year-old’s response to his rough major-league debut suggests Beeks could get the call again. Since returning to Triple-A he’s posted a 1.93 ERA over three starts, with 21 strikeouts compared to 20 baserunners. He’ll remain on Boston’s radar as long as that continues.

29. Bobby Poyner – Lefties are just 2-for-14 this season against the southpaw who’s currently at Pawtucket. Robby Scott is there, too, but both have had some left-on-left success in the big leagues, and based on the current configuration there’s a chance for either to emerge as an important piece of the Boston bullpen.

28. Tyler Thornburg – Travis Shaw has slugged 45 homers for the Brewers since he was traded for Thornburg – who has yet to pitch in the majors for Boston, and who has a 5.40 ERA and 1.58 WHIP through 16 rehab appearances at Triple-A. It’s hard to envision entrusting his shoulder with a prominent role at any point this season.

27. Blake Swihart – On June 1, Hanley Ramirez was formally released in a decision the team said could create more of an opportunity to play Swihart. Since then he has eight starts, 32 plate appearances, and four hits. His role continues to reside somewhere between undefined and pointless.

26. Tzu-Wei Lin – Lin was recalled this week while Xander Bogaerts dealt with a minor hand injury, but has now been on the big-league roster for 31 days this season – with 40 plate appearances to show for it. He could fit as a defensive replacement for either Rafael Devers or Eduardo Nunez, but only seven of the 62 games he’s started this season (in the majors and minors) have come at second or third base.

25. Brandon Workman – The righty has surrendered just a run in eight innings, while registering 10 strikeouts. He once entered in a tied game, but otherwise Alex Cora has only called on him with the Sox leading by at least five runs or trailing. Let’s see if Workman earns more trust.

24. Dustin Pedroia – He hasn’t played since May 31, and his latest knee rehab hasn’t yet progressed past the treadmill. It’ll be a while, and even then it may never be resolved, but the potential of Pedroia (even now) remains an upgrade on the present options at second base.

23. Brian Johnson – He didn’t get the win, but Johnson salvaged one for the Sox with 2 2/3 shutout innings after Steven Wright’s stinker against the Mariners last Friday night. It dipped the lefty’s ERA to 2.00 for June, when he’s affirmed his value as a middle reliever.

22. Hector Velasquez – Conversely, Boston’s other long option in the bullpen has struggled some of late. After starting the year with a 1.82 in 19 games, Velazquez has yielded four runs and nine hits in his last five innings of work.

21. Drew Pomeranz – His is the injury rehab Sox fans should follow the closest. He threw off a mound last week, and although his ERA is pushing seven this season he is almost certainly going to be given the chance to a difference maker for Boston, whether it be as a fallback for Wright’s fickle knuckler or as a proven lefty out of the ‘pen.

20. Jackie Bradley Jr. – If you’re looking for a reason to believe in Bradley, consider this: According to Statcast, his average exit velocity of 91.6 mph ranks 29th in all of baseball – 0.7 mph behind Manny Machado, and 0.7 ahead of Nolan Arenado. His .581 OPS is fifth-worst in the majors, so the results aren’t there, but Bradley’s annual torrid stretch may be forthcoming.

19. Heath Hembree – His walk rate is troubling, but Hembree has allowed just one hit in nine June appearances. Cora seems to trust him, though the righty has yielded seven runs in three appearances against the Yankees this season – and seven runs in 29 appearances against everyone else. This weekend could be big for him.

18. Eduardo Nunez – Better suited for a utility role, Nunez’s turn as Boston’s everyday second baseman has been marked by below-average performance at the plate and even poorer defense. He doesn’t have an extra-base hit in June, and is giving the Sox reason to pursue help at the trade deadline if Pedroia isn’t progressing as hoped.

17. Sandy Leon – Boston’s pitchers have performed better this season when throwing to Leon than to Christian Vazquez, and his partnership with Rick Porcello continues to be particularly effective. Big hits (like he had in Minnesota last week) after an occasional bonus, as well.

16. Christian Vazquez – According to Baseball-Reference, Leon’s wins above replacement is 0.4. Vazquez, meanwhile, is second-worst on the club at negative-0.8. His .538 OPS is fourth-worst among all major leaguers who’ve stepped to the plate at least 190 times. And yet the Sox are 35-14 when he starts (17-13 when he doesn’t). Go figure.

15. Steven Wright – The knuckleballer was pounded by the Mariners on Friday, when his ERA ballooned from 1.23 to 3.38 in just 3.1 innings of work. For now, at least, it’s merely an aberration in what has been six solid weeks of work from Wright.

14. Brock Holt – En route to the 2015 All-Star game, Holt had a .791 OPS over the first half. He takes a .784 OPS into Tuesday, while playing five positions. He’s again proving his value, though sustainability remains a question for a player whose career OPS drops 170 points in the second half.

13. Eduardo Rodriguez – Saturday’s loss ended a run of eight starts in which Rodriguez surrendered three runs or fewer, and marked only Boston’s second setback in the 15 times he has taken the ball. At age 25, the incremental improvement continues for the lefty.

12. Rafael Devers – He’s up to 29 errors in 130 big-league games, which is a problem, but it’s a problem the Sox might be more willing to live with in exchange for some pop from their third baseman. Since snapping a 17-game homerless streak on June 12, Devers is slugging .510 and has multiple hits in three of his last seven contests. He’s got to keep that up if his bat is going to justify his glove.

11. Matt Barnes – Opponents are nine for their last 55 against the righty. He’s on pace to set career bests in hits (5.1) and strikeouts (12.0) per nine innings, which is an excellent combination for a late-inning reliever who has emerged as a vital piece of the bullpen puzzle.

10. Joe Kelly – Through May the righty was looking like an All-Star candidate, and while a 7.71 June ERA has likely spoiled those chances, Kelly retains the trust of his manager. Where has Barnes has inherited just three baserunners since the end of April, Kelly has inherited 19. When in a jam, and not yet ready for Craig Kimbrel, Cora appears to trust Kelly as much as anyone.

9. David Price – Regardless of the expectations that come with his paycheck, the lefty has been fine this season. No better, no worse, as suggested by a WAR calculation of 0.7 that rates him as the 24th-most valuable pitcher in baseball. Before getting too excited by what he’s done lately, however, consider that his WAR ranks 31st in June – 17 spots behind old friend Clay Buchholz.

8. Xander Bogaerts – The shortstop is on pace for 40 doubles, 24 homers, and 88 RBI, which would constitute a more productive campaign than either of his two previous Silver Slugger seasons. Fangraphs calculates his value to be 2.7 wins above replacement through 79 games – same as Astros stud Carlos Correa, and among the handful of baseball’s best shortstops.

7. Mitch Moreland – Both Carlos Santana and Eric Hosmer were mentioned as possibilities to become Red Sox while free agents this past winter, though – after signing for a fraction of either’s deal – Moreland has dramatically out-hit each of them. His .937 OPS is 12th-best in baseball among hitters with at least 200 plate appearances, and he’s yet to slow down much after a sizzling start. His re-signing seemed curious at the time, but score one for Dave Dombrowski, and to Moreland for seizing the opportunity.

6. Andrew Benintendi – On May 4, after his second consecutive 0-for-4, he was hitting .239 with one homer. The next day Benintendi finished a long ball shy of the cycle, sparking a 45-game stretch during which he’s slugged 12 taters and posted an OPS of 1.010. Now his numbers are at a point suggesting his growth as a hitter is exactly where a team would want those of a 23-year-old cornerstone to be.

5. Rick Porcello – A year ago, Porcello had a tendency to spoil his outing by giving up an ill-timed home run, finishing the year with a major league-high 38 gophers allowed. This year he’s reduced that rate dramatically – 4.3 percent down to 1.9 – and the result has been a return to the dependable, consistent right-hander who at this point projects as Boston’s No. 2 starter in the postseason.

4. Craig Kimbrel – His workload has been light this month (limited to six innings so far), but Kimbrel has yielded only one hit in June. He’s converted 13 consecutive save chances, and while he’s not striking hitters out at the same rate he was a year ago he’s still surrendering less than a baserunner per inning. The Red Sox bullpen has the third-lowest ERA in the AL, though without Kimbrel it could easily become a disaster.

3. Mookie Betts – In 11 games since returning from the disabled list, Betts has two extra-base hits and is hitting just .250, yet his batting average is still second in the league, and he leads the AL in slugging percentage. When adding baserunning and defense to the equation, it’s not difficult to make a case that Betts has been the best all-around player in the American League not named Mike Trout.

2. Chris Sale – Sale struck out 13 over seven innings on Sunday, punctuating his afternoon by hitting 100 mph on the radar gun. Such has become routine for a guy who has struck out nine or more in 34 of his 49 regular-season starts for the Red Sox (Jon Lester had 35 in 241 Sox starts), but his importance should never be downplayed. The AL’s four other legitimate contenders boast Corey Kluber, Luis Severino, and Justin Verlander atop their rotations. Without Sale, Boston couldn’t match up; with him, they belong in any conversation of contenders.

1. J.D. Martinez – In their first post-David Ortiz season, Betts led the Sox in homers with 24. He also led the team with 288 total bases. Coming out of the weekend, Martinez already has 23 home runs and is on pace to pile up 385 bases this season, offering a glimpse into how much of a game-changer Martinez has been in the middle of the Boston lineup. His 60 RBI lead the majors, too, and he’s hitting .325 while reaching at a .393 clip. From the start, on a daily basis, nobody is a bigger reason why the Sox are in this position than the player they signed on February 26.