Brian Kersey, Associated Press Boston's David Ortiz arrives at PNC Park tonight leading the majors in homers with 31.

Ramon Henderson's arm caught a Home Run Derby break Thursday: Bobby Abreu lost in the Final Vote campaign.

Going by last year's garish numbers, Abreu's absence probably will save this Philadelphia Phillies bullpen coach 60 pitches and one appendage, minimum.

Still, it doesn't give him the night off. For Henderson's services as a batting-practice pitcher, at the suggestion of defending-champion Abreu, will be offered to fellow Phillies slugger Ryan Howard tonight, when the Home Run Derby comes to PNC Park with an aim completely foreign to the previous 20 incarnations of the manic Monday blastoff -- a watery finish in the Allegheny River.

	Home Run Derby Rulebook First round 10 outs to hit as many HRs as possible. Four players with the most HRs -- regardless of league affiliation -- advance to the semifinals. Semifinals HR totals don't carry over, so each competitor restarts at 0. Again, 10 outs to hit as many HRs as possible. Two players with the most HRs in the semifinals advance to the championships. Championships HR totals from first round and semifinals don't carry over. Again, 10 outs to hit as many HRs as possible. Player with the most HRs in championships wins. Of note: An out is recorded when player swings at a pitch and fails to hit HR; a ball must be hit in fair territory to count as HR. Related information The Ultimate Derby: Babe Ruth is still the King The Home Run Derby dream ballots: How they voted A guide to the Home Run Derby Multimedia: How to make a home run splash All-time Home Run Derby results

Even if Howard finds himself unable to come anywhere close to Abreu's Derby record of 41 homers last July at Detroit's Comerica Park, at least he can try for a splashdown over the Clemente Wall, right-field bleachers, hillside and sidewalk beyond. It's a new twist to a generation-old contest, unlike the Hit the Warehouse competition of the 1993 Derby at Camden Yards or Hit the Hotel at then-SkyDome in 1991.

Don't bet your boat on such a water shot, though. Because this Derby madness isn't as easy as it appears.

Just ask Pirates outfielder Jason Bay.

Last year, when the Derby format opted for an international flavor, Bay represented his native country and mustered nary a homer. As any Canadian will tell you, a shutout is a good thing only in hockey.

"The biggest thing for me -- and this is going to sound very trivial -- is taking BP in a stadium without a cage," Bay explained of the unusual Derby environs. "It's a really big deal. Everyone told me about it beforehand, and you can't imagine it's an issue.

"But, when you get in there, you're up there with a catcher and a pitcher behind an L-screen, and you feel like you're in the middle of nowhere. It's very weird, very uncomfortable, because you've never done it. If you could do that for a few minutes every day leading up to the Derby, I'm sure that would help.

"I didn't. ... I didn't take early hitting for it. I didn't change my swing to try to hit home runs. It's not your regular BP stroke. You're definitely trying to do something different."

That doesn't bode well for Howard, who enters the clash tonight with 28 homers thus far, one behind National League leader St. Louis' Albert Pujols, who decided to sit out the Derby just a few weeks after coming off the disabled list.

Howard admittedly isn't a for-the-fences kind of guy, preferring instead to spray line drives as pregame work.

"I don't hit home runs in batting practice," Howard told reporters last week in Philadelphia. "I'm not saying I can't hit them in practice. I just don't."

Henderson added, "It's pretty difficult to do what Bobby did [last year]. But Ryan has some unbelievable power. He loves pitches outside. I'm going to tell him to pull the ball for one day."

Swatting for walls, let alone water, has its disadvantages. Abreu smacked just six homers after the 2005 All-Star Game and only eight this season. Milwaukee's Carlos Lee, who withdrew Monday because of a lingering left hand injury, wondered aloud late last season if the made-for-TV competition messed up his swing and contributed to his dwindling homer total the rest of the way. And his replacement, Houston's switch-hitting Lance Berkman, already has decided to try the contest from the right side of the plate so as not to affect his timing from the left -- something that became a problem for him four years ago.

This Derby is a different breed of race anyhow, with a full house screeching for nothing but longballs and an ESPN audience that annually ranks among its summer-TV highest. Sometimes, this attention revs a competitor, such as Abreu of Venezuela last summer, when he banged a record 24 on his lengthy first turn and another record 11 in the finals. Baltimore's Miguel Tejada established the previous high a year earlier with 27 total, but that American League reserve chose to sit out last year's contest and planned to be a spectator at this one until MLB types got a shade desperate, talking him into it.

The rest of tonight's field is set to include: Berkman (24 homers), Florida's Miguel Cabrera (15) and the Mets' David Wright (20) for the NL plus American League stars David Ortiz of Boston (the major-league leader with 31), Toronto's Troy Glaus (23) and the Chicago White Sox's Jermaine Dye (24). If you're looking to handicap that field, Ortiz has bashed six homers in the past week since accepting a Derby invite -- he wants to raise charity money for a heart clinic in his native Dominican Republic -- and Dye has bashed four.

Contrast that list to the slugging All-Stars present in PNC Park tonight, but spectating only: the White Sox's Jim Thome (30), Pujols, Washington's Alfonso Soriano (27), Lee (26), the Mets' Carlos Beltran (25), the White Sox's Paul Konerko (21), Toronto's Vernon Wells (21), Bay (21), Atlanta's Andruw Jones (20), the Yankees' Alex Rodriguez (19) and the Angels' Vladimir Guerrero (18).

Perhaps the difficulty of this event is best explained by its perplexing pantheon of former champions. Anaheim's Garrett Anderson in 2003 over Pujols, Delgado plus the Yankees' Jason Giambi and Gary Sheffield? Arizona's Luis Gonzalez in 2001 over Chicago's Sammy Sosa, Giambi, San Francisco's Barry Bonds and Rodriguez? The Yankees' Tino Martinez in 1997 over Oakland's Mark McGwire, Colorado's Larry Walker and three-time winner Ken Griffey Jr. of Seattle?

To hit as many home runs as possible among the 10 potential outs, it helps to follow a couple of pointers: swing high and hard; pace yourself (as Giambi proved in 2001 by flaming out after a 14-homer first round); and work for a groove.

Maybe most important, though, is to bring a favorable BP pitcher.

Bay didn't last year.

Abreu did.