APR: 15-8   MAY: 17-8
Biggest difference: Bob Porterfield
The Spider ace's ERA nearly tripled in May, but so good was his April form (1.09) that Porterfield still managed a 6-1 record and 2.91 ERA to anchor the league's third best pitching staff.
Honorable mention: Wes Covington
The left fielder drove in 20 runs in 20 games after a lackluster April, adding some punch to a young lineup.
 

APR: 17-6   MAY: 20-7
Biggest Difference: Gene Conley
The already-awesome 28-year-old (5-1, 2.58 in April) got even better in May (6-0, 1.25), leading the league in ERA and wins to nab Pitcher of the Month.
Honorable Mention: Granny Hamner
Granny led the league in batting both months, leading the top batting trio of Hamner, Amoros, and Landrith.

APR: 14-8   MAY: 13-14
Biggest difference: Rocky Bridges
Louisville improved to become the league's top pitching team in May, yet still posted a losing record as the runs dried up at Parkway Field.  One of the leading culprits was Bridges, who earned a full-time role after driving in 11 runs with a .306 average in April, only to hit .248-0-6 as a full-timer in May.  
    The Colonels are also 0-5 in extra-innings, thanks to Hank Aaron (.100), Nellie Fox (.125), and Ed Bailey's (.130) abysmal batting with runners in close/late situations (only SF's Ken Boyer is worse).
 

APR: 10-13   MAY: 14-15
Biggest difference: Dusty Rhodes
The scrappy Alabaman turned the club's second worst April OPS (.690) into the best in May (.926).  Rhodes hit .365-2-20 in May, leading the team in batting and RBIs.  On May 7, Dusty had 5 hits, including a pair of home runs, and drove in 6 runs. 
Honorable Mention: Joey Jay
Jay was 1-6, 4.92 in his first 10 starts, but is currently the Griffins' hottest pitcher, with a 2-0 record and 2.52 ERA since May 18.
 

APR: 10-14   MAY: 18-9
Biggest difference: Warren Hacker
The promotion of Hacker, a former 20-game winner, stabilized a Maroon rotation that was in turmoil.  Hacker was won every game he started since his May 4 callup -- his first UL action after a full season in AAA.  Hacker's 5-0 record and 1.76 ERA were both team pacesetters.
Honorable Mention: Stan Musial
Musial nearly doubled all his averages in May, raising a .169 average and .338 SLG into a torrid .389 average and .593 SLG in May.
 

APR: 10-13   MAY: 12-15
Biggest difference: Sore arms
The Barons have tried nine starts already these season, and none have impressed.  The only consistency to Cleveland's pitching has been a string of injuries: Luis Arroyo (season), Billy O'Dell (3 wks), Bud Daley (6 wks), Carl Willey (7 wks).
Honorable Mention: Eddie Mathews
The slugging third-sacker stepped up his production in May from 8 RBI to 27 RBI -- a key contribution that helped compensate for the league's most generous pitching staff.
 

APR: 12-11   MAY: 8-19
Biggest difference: Barney Shultz
Starter Tom Sturdivant went from 3-3 to 0-6 despite lowering his ERA, signaling either a drop in run support or bullpen failure.  Well, the offense has tapered off across the board, but no single player personifies the bullpen collapse quite like Barney Schultz.  While leading the team in appearances both months, Schultz went from the best (1.42) to the worst (9.75) reliever on the staff.  The 32-year-old righthander has struggled since 1957, when 27 saves and a 3.78 ERA earned him a five-year, $1 million a year contract.
  

APR: 10-13   MAY: 12-15
Biggest difference: Joe Ginsberg
GM Shawn Martin's $2.2 million gamble on catcher Joe Ginsberg looked like a bust after a lackluster April (.186-0-5), but the veteran backstopper got hot in May (.333-1-14) with the club's second best OPS (.909).
Honorable Mention: Bob Hooper
The righthanded set-up man is still far from his peak form that saw him post 20+ saves in six straight seasons, but the 36-year-old is on the right track after slicing his April ERA in half (5.40 to 2.93) and earning career saves #216 and #217.
 

APR: 10-13   MAY: 9-19
Biggest difference: Ed Bouchee
L.A.'s pitching actually jumped from 10th to 6th in May, but the club faltered thanks to a lineup that only produced 102 runs in 28 games (3.6 per game).  Though only a part-time player, Ed Bouchee went from key contributor to massive liability in the span of two fortnights.  The 26-year-old Montana hit .316-4-11 in April, only to fall flat on his face in May, with just 4 hits in 43 at bats (.093-0-1 in 20 games).
 

APR: 7-16   MAY: 12-14
Biggest difference: Duke Snider
The Silver Fox's return to full-time duty after a year on the DL with a broken knee was a shot in the arm for the Monuments' offense.  Duke hit .291-6-20 in May, with a .961 OPS that was second to only Willie Mays.  Despite a career plagued by tough breaks -- military service in 1953, an abysmal 1957 (.212 average, .679 OPS), and last year's injury -- the 31-year-old is still young, and is on track for his finest season since 1956.
Honorable Mention: Ned Garver
"Gives Good" Ned was the worst starter in April (1-2, 5.47), and the best in May (4-2, 2.98).