The Astros have battled through three seasons of a major overhaul, and they like to think their effort is starting to pay off. They went 15-14 in May, their first winning record in a full month since September 2010, thanks to a seven-game winning streak, which was snapped on Saturday. Houston had gone 19 consecutive full months without a winning record, and it was a combined 186-358 (.342) during that stretch, the worst record in the big leagues. The Cubs recorded the second-worst record in that stretch at 218-322 (.404).
More than the record, the Astros are excited about the emergence of George Springer, the 11th player taken in the first round of the 2011 First-Year Player Draft out of the University of Connecticut. After struggling when he was called up in April, Springer hit .294 in May, finishing third in the American League with 10 home runs and tied for fourth with 22 runs. He also had 25 RBIs in 26 games. Dallas Keuchel anchored the rotation in May with a 4-2 record and a 2.14 ERA, sixth best in the AL.
After a 17-game stretch over 17 days in which they went 10-7, the Astros were off on Monday, enjoying the fact that they have a better overall record (24-34, .414) than the Rays (23-34, .404), the D-backs (23-36, .390) and the Cubs (20-34, .370).
OK, the Royals didn't totally disappear like they did in May a year ago, when they went 8-20 during the month, including a 5-20 stretch. But the Royals did create concerns with another May fade. Sitting 1 1/2 games back of first-place Detroit in the American League Central when the month started, they have lost 18 of 30 since then, having fallen into last place -- 6 1/2 games out of first.
The Royals were a part of the Astros' turnaround. Houston went into Kansas City and swept a three-game series against the Royals, who scored only five runs while giving up 21. It is the Astros' lone sweep of the season.
Two of the young arms in the rotation are struggling. Yordano Ventura was 0-4 with a 5.60 ERA in May and missed a start with an elbow problem, although the Royals are optimistic he won't need Tommy John surgery, and Danny Duffy went 1-4 during the month.
Up: Blue Jays
The Blue Jays went a Major League-best 21-9 in May, and they christened June with a 4-0 win over Kansas City on Sunday. Toronto climbed from fourth place, 3 1/2 games out of first, to the top of the AL East with a 2 1/2-game lead at the end of May and opened June by adding another game to its lead.
Mark Buehrle, who went 5-0 with a 2.48 ERA in May, became baseball's first 10-game winner on Sunday, giving the main four in the rotation a 16-4 record in 24 starts since May 1. J.A. Happ went 4-2, and R.A. Dickey and Drew Hutchison were each 3-1.
Edwin Encarnacion went on a power binge, hitting 16 home runs, which equaled the AL record for May, originally set by Mickey Mantle in 1956. Encarnacion had five multihomer games during the month, equaling the single-month record set by Harmon Killebrew (May 1959) and also matched by Albert Belle (September 1995).
Well, Jeff Samardzija did finally claim his first victory of the season on May 26, an 8-4 win in San Francisco. He struck out 10 and didn't walk a batter in seven innings. His encore on Sunday wasn't the same. He allowed eight runs in three innings of a 9-0 loss to Milwaukee, his ERA climbing from 1.68 to 2.54. Samardzija had allowed eight earned runs combined in 39 2/3 innings over his six previous starts. In his first 10 starts of the season, he had not allowed an earned run in four starts, given up just two earned runs in three starts and also permitted three earned runs and one earned run in two starts each.
It's been that kind of season for the Cubs. How big is the struggle? Well, in the previous 138 years the franchise has been in existence, they have had a winning percentage worst than their current .370 only three times -- .364 in 1966 and '62, and .369 in '81.
Yes, the Giants are back. As World Series champions in 2010 and '12, the Giants have a 7 1/2-game lead over the Dodgers in the National League West, a lead greater than the other division leaders. They expanded their edge on the rest of the division by six games since May 1. The Giants were an NL-best 19-9 in May, leading the Majors with a 2.91 ERA and ranking third in the NL with 123 runs scored.
Pablo Sandoval is beginning to shake off the thought over the pending free agency that put him in a funk. Hitting .171 on May 9, he is 31-for-84 since, raising his average 80 points, and he has hit six home runs with 19 RBIs in the past three weeks.
Madison Bumgarner set the pace in the NL with a 5-0 record during May, compiling a 2.08 ERA. More importantly, Tim Lincecum (3-2, 2.86 ERA) and Ryan Vogelsong (3-1, 2.29 ERA) continued their rebound seasons.
As if they haven't struggled enough -- losing 16 of their past 25 games -- the Phillies are in the midst of a 20-game stretch without an off-day, and the past three went into extra innings. A worn-out pitching staff has worked 39 innings against the Mets, including back-to-back 14-inning games on Friday and Saturday.
Ryan Howard has been an all-or-nothing factor in the middle of the lineup. During the Phillies' 25-game stretch, he hit five home runs and driven in 22 runs, but he is hitting .208 and has struck out 32 times while drawing 14 walks in 107 plate appearances. Jimmy Rollins (.226) and Domonic Brown (.159) have not provided any consistency either.
The Phillies have been shut out in six out of the 25 games, and the bullpen has only had six save opportunities -- four for closer Jonathan Papelbon, who converted each of them. He was unscored upon in nine out of his 10 appearances during that stretch.
Tracy Ringolsby is a columnist for MLB.com.