Ten reasons to believe in Red Sox

DENVER -- The Boston Red Sox are a half-game out of first place in the American League East just over a month after one of the worst losses they'd ever absorbed against the New York Yankees, the May 17 game in which they came back from 5-0 to take a two-run lead in the ninth on the strength of five home runs, only to lose when Alex Rodriguez and Marcus Thames hit two-run home runs off Jonathan Papelbon in the bottom of the inning.

That loss dropped the Sox to a game under .500 (19-20), the latest in any season since 1997 that they dropped below sea level, and 8½ games out of first place, and had one Boston columnist calling them "The Lost Boys of 2010."

Since then, the Sox have gone 24-8 and arrive in Denver a game behind the Yankees and tied with the Tampa Bay Rays for second in the AL East.

Here are 10 reasons why:

1. The Comeback

Papelbon and the Sox climbed off the mat the next night against the Yankees, once again overcoming a five-run hole, with Papelbon striking out Randy Winn with the potential tying and winning runs on second and third to preserve a 7-6 win.

"The season's a heavyweight fight,'' Papelbon said that night. "You can't knock me out with one blow, you know what I mean?''

Normally, it's a silly exercise to single out one game to explain a team's turnaround, but there are exceptions. One was the A-Rod/Jason Varitek rumble in Fenway Park in 2004, followed a week later by the Nomar Garciaparra trade, both events that had seismic consequences on the way the team performed throughout the rest of the season. This game had that feel to it -- the Sox had lost eight in a row in Yankee Stadium, were 2-9 overall against the Yanks and Rays, and had reason to wonder if they were on a bridge to nowhere. Instead, they gained a reason to believe.

2. The Daisuke resurgence

If Papelbon's rope-a-dope KO of the Yanks wasn't the most important game the Sox have played in this stretch, then it was Daisuke Matsuzaka's near no-hitter of the Philadelphia Phillies four days later in Philadelphia. Matsuzaka had been routed by the Yankees in his previous start, he'd been near tears after another poor outing in Baltimore, and there were legitimate questions as to whether he would be a nonfactor for the second season in a row. Instead, he responded with perhaps his best performance with the Sox, taking a no-hitter into the eighth against the Phils and finishing with a complete-game one-hitter.

Matsuzaka's timing couldn't have been better. It came just after Josh Beckett's back gave out on him. Beckett has been out since, but that hasn't hindered the Red Sox from creating reason No. 3 on the list.

3. Terrific starting pitching

Sox starters had a 5.16 ERA after that loss to the Yankees, and were at the bottom of the league in that category. Since then? They're 21-6 in decisions with a 3.18 ERA.

Clay Buchholz, who threw a combined 2-0 shutout against the Los Angeles Dodgers on Sunday night, is 6-1 with a 1.64 ERA in seven starts in that span. Jon Lester is 5-0 with a 2.18 ERA. Matsuzaka, who is coming off another stint on the DL to start in Denver on Thursday, was 3-1 with a 1.98 ERA in four starts. John Lackey hasn't been as impressive, except in his ability to win: He's 4-1 with a 4.10 ERA in his last six starts.

4. Big Papi, unleashed

David Ortiz was still batting .235 on May 17, but he'd already begun to heat up and has added over 100 percentage points to both his on-base average (.301) and slugging percentage (.500 to .612). No more platoon and no more sullen walks back to the dugout. The swagger is back, and so is his ownership of the No. 3-hole.

5. V-Mart is upscale again

These were uncertain times for Victor Martinez. The Sox elected not to address his contract situation. Opponents were running wild on him. The performance of the Sox's starters brought his game-calling skills into question. And, he wasn't hitting.

On May 17, he was batting .234 and his .OBP was just .291.

Since then, he has been the team's hottest hitter, putting up these numbers: .378/.426/.667.

6. Beltre regains leading-man form

His exceptional fielding notwithstanding, Adrian Beltre's five years with the Seattle Mariners were generally regarded as a disappointment, because he never came close to resembling the slugger that he was with the Dodgers.

His agent, Scott Boras, insisted that Beltre needed only a change of scenery. The Red Sox were able to nab him on short money in a generally indifferent market, with the third baseman rightly deciding that Boston would be a better place than Oakland to jump-start his career, even though the Athletics had a multiyear deal on the table.

From the outset, Beltre hit for average -- he was batting .312 on May 17 -- but since that date the power also has returned, his eight home runs in that span gave him 10 overall, or one more than he hit for Seattle in 2009.

Don't be deceived by Beltre's high error total. When he hasn't botched the occasional routine play, he has played phenomenal defense.

Beltre's bat has stretched out the Sox lineup that belies its Run Prevention U. label, as the Sox are leading the majors in runs, averaging 5.9 runs a game over their hot streak. Kevin Youkilis has been the relentless beating heart in that lineup, Dustin Pedroia has broken out of an extended slump to offer his nightly laser shows and J.D. Drew keeps finding his way on base, making this Sox lineup not as scary as the Manny days, but in some ways more productive.

7. Interleague play

The Sox should be sorry that this week's trip to Denver and San Francisco brings a close to the interleague portion of the program. The Sox have mopped up again against their NL brethren, going 10-2 thus far. The Rays, meanwhile, are just 5-7 and coming off their first losing road trip, which came against NL rivals Atlanta Braves and Florida Marlins. That's a five-game swing for the Sox right there.

8. The Rays come back to earth

Tampa Bay was in first place for 59 days before ceding the spot to the Yankees on Sunday. In their last 25 games, they're 10-15, with a team ERA of 5.72. That's three runs higher than the staff ERA after their first 44 games. The offense has been inconsistent, too, but James Shields is 2-5 with a 6.63 ERA in the last month, Wade Davis is 2-4 with a 6.97 ERA, and Matt Garza is 2-4 with a 7.03 ERA.

9. The Yankees have issues

A-Rod's hip is a concern. A.J. Burnett has been his typically erratic self (2-4, 5.80 ERA in the last month). Joba Chamberlain (8.25 ERA over his last 12 appearances) is no Daniel Bard. Mark Teixeira is starting to heat up, but there are cracks.

10. The manager rocks steady

Terry Francona predicted better days -- for Ortiz, for the pitching, for the catching and for the ballclub. He has made 20 different outfield combinations work. He should be getting Jacoby Ellsbury and Beckett back around the All-Star break. The Sox aren't going to play .750 ball the rest of the way. But they are far from lost.

Gordon Edes is ESPNBoston.com's Red Sox reporter. He covered the Red Sox for 12 years and has reported on baseball for 25 years. Ask a question for his next mailbag here.