No one in baseball was sorrier -- or maybe happier -- to see May end than Dan Uggla. The Marlins' second basemen accumulated a summer's worth of positive numbers in the first three weeks of the month and then struggled at its end.

Uggla hit 12 home runs in May, leading the Major Leagues, and setting a single-month franchise record and becoming the first Marlins player to lead the league in home runs for an entire month.

After a sluggish start in April, Uggla dropped from the No.2 spot in the Marlins' lineup to No.5 and batted over .400 for most of May in his new position in the lineup. His batting average rose from a dreary .245 to above .300. He had his first career grand slam and the second two-home run game of his career.

Then the last week of the month arrived, and Uggla's hot streak fizzled. He went a dismal 3-for-21 and proved that there are no guarantees in the game of baseball -- even for the Major's hottest hitter.

"You can be locked in, have it all together in one at-bat and lose it on the next one," Uggla said. "That's what's crazy about baseball, but it evens out over a season. That's why it's 162 games."

The ups and downs are nothing new for Uggla, though. He's always had difficult starts.

"It's kind of weird," he said. "Some guys start slow. Some start hot. Who knows why? There's no reason. I'd like to start hot one of these years."

Uggla's been around long enough to know all about baseball's roller coaster. He also understands how success in the game comes and goes.

"Baseball will humble you if you let it," he said. "You just try and ride the wave as long as you can."

The wave he's been riding has kept baseball fans buzzing. There was an 11-game hitting streak and a special Sunday when he homered in the first game of a doubleheader against San Francisco and drove in the winning run with a walkoff single in the nightcap.

"He was hitting everything," said manager Fredi Gonzalez.

Uggla's big league success was a long shot. He came to the Marlins as a Rule Five draft choice, grabbed off baseball's scrap heap. He had had been stuck in Arizona's Minor League system, bouncing around the organization for five years after being drafted out of the University of Memphis in the 11th round in 2001.

When Arizona signed Orlando Hudson in 2006, Uggla was squeezed out of the Diamondbacks' 40-man roster, available in baseball's bargain basement marketplace. He had been down this road before: available and ignored.

"It's tough," he said. "You've got to have a good year in Double-A or Triple-A to convince a team to take a chance," Uggla said.

The Marlins, still in reconstruction mode after winning the World Series in 2003, paid the Rule Five fee of $50,000 to get a look at Uggla and they've never regretted their choice. He's perhaps the most successful player to come out of the Rule Five grab bag in the last decade and has paid a handsome return on Florida's investment.

Uggla moved right into the lineup in his first season and batted .282 with 27 home runs. He was selected for the All-Star team that season, the first Rule Five player to achieve that honor, and finished third in the Rookie of the Year balloting.

There was a slide last year, when his batting average slipped to .245, but he still hit 31 home runs and remained an important part of the Marlins batting order. However, he has never been more centric to his team's success than this past May.

If there is any lesson to learn from Uggla's situation, it's this: Next December, when Major League Baseball conducts its afterthought Rule Five draft, there just might be some players worth paying attention to.