Bonds, Griffey chase milestones; Yanks' uphill battle

In the weeks and months ahead -- maybe just days, if Barry Bonds goes hog wild -- we will all witness a historic confluence of events in Major League Baseball, the likes of which has never been seen in the game. A new career home run record, the first in more than 30 years, will be set, courtesy of Mr. Bonds. A player will join the ranks of the still-elite 500 home run club and, maybe not long after that, another will slam his way into the 600 club. A pitcher will notch career win No. 300. All of this could come in the second half of this season.

That mountain of milestones isn't all that baseball will have to offer after the All-Star break. There are the rumors and the possibilities of the trading deadline as well as the drama and disappointments of the pennant races. There are trophies to be won, contracts to aim for and careers to wind up, too.

Here are the 10 most compelling storylines for baseball's second half:

Bonds overtakes Aaron

So here we are, finally. Bonds is five away from breaking Hank Aaron's record of 755 home runs in a career. In recent years Bonds would knock out five homers in a week or so. I remember one memorable May weekend in Atlanta in 2001 when he punched out six. It's going to take a lot longer than that for the soon-to-be 43-year-old slugger to hit five nowadays, though, which may well put us into August until he reaches the magic moment. Consider this when making your Bonds-viewing plans: His last five homers took three weeks (from June 11 to July 3) and 18 games. And if he and the Giants are trying to time this so he can launch the record-breaker at home in San Francisco's AT&T Park, it may take even longer.

Ken Griffey Jr. aims for No. 600

Griffey is in the middle of his best season ever in Cincinnati. He had 23 homers at the break, a .390 on-base percentage (his best in a decade) and he looks as healthy as he has since they called him The Kid in Seattle. With 14 more home runs -- that'll come some time in September, if he keeps this up -- he'll become the sixth player ever (and the second player this summer, joining Sammy Sosa) to reach 600 homers in a career. It's funny, too: We'll all feel a lot better about Griffey getting his -- especially given all he's been through -- than we did about Sosa, or we will about Bonds grabbing the all-time record.

Alex Rodriguez shoots for No. 500

If there's one player we can point to who might be able to catch Aaron and then knock Bonds off the homer roost, it's the Yankees' Rodriguez, who cranked 30 first-half home runs to get him to within six of career homer No. 500. Only 21 players have hit 500 homers in a career, which is still a pretty significant milepost on the road to Cooperstown. A-Rod will be the second player this year (with Frank Thomas), the fifth active player (joining Thomas, Bonds, Griffey and Sosa) and the seventh in recent years (with Mark McGwire and Rafael Palmeiro) to crack No. 500. As for his chances of eventually overtaking Aaron and, possibly, Bonds? Bill James, in his latest Handbook, gives A-Rod a 50 percent chance to hit 700 homers in his career and a 31 percent chance to break Aaron's record. If he stays healthy, James projects that A-Rod will finish his career with 772 home runs. He has Bonds at 884, which, considering he turns 43 this month, seems high.

Tom Glavine goes for win No. 300

The Mets' crafty lefty -- aren't all lefties "crafty," just like all undersized shortstops are "scrappy?" -- is three wins away from becoming the 23rd player to win 300 games in a career. When he gets there, he'll likely be the last to crack the barrier for awhile, unless Randy Johnson (with 284) talks his balky back into cooperating. It took Glavine 10 starts to get his last three wins, so this might not be pretty. But he'll almost certainly get there, joining Roger Clemens and Greg Maddux among active players in the club. Next up after Glavine and possibly Johnson to 300? In his analysis, James says it is "likely" that at least one more active player will make it, but it's a long way for everyone and no one stands out as a front-runner.