What's the worst-case scenario for Phillies?

OK, let's do some quick math.

By worst-case scenario, I don't mean "Chase Utley out of for the year, Ryan Howard out for the year, Roy Halladay injures his shoulder" and so on.

But let's try a few assumptions and see how that could affect the Phillies' bottom line in terms of wins and losses.

1. Chase Utley misses half of the season.

We'll slot Freddy Galvis in his place. Projecting Utley with the same numbers as last season, this would be a net loss of about 15 runs over 300 plate appearances.

2. Ryan Howard misses half of the season.

While Howard is no longer the $20 million superstar his contract suggests, he did create 97 runs in 644 plate appearances. Some combo of John Mayberry, Ty Wigginton and Jim Thome isn't going to match that, especially if Wigginton gets too much playing time. Let's say 10 runs worse over 300 plate appearances.

3. Declines from Shane Victorino, Jimmy Rollins, Placido Polanco and Hunter Pence.

The first three are a year older. Pence played out of his mind for two months. Let's say 25 runs worse.

4. Decline from Roy Halladay, Cliff Lee, Cole Hamels and Vance Worley.

I'm not talking huge drop-offs here, but it's hard to imagine the Big Three doing any better. Halladay allowed 74 runs in 2010, 65 a year ago (albeit in fewer innings). In Lee's first stint with the Phillies, he allowed 35 runs in 12 starts; in 2011, he allowed 66 in 32 starts. Hamels allowed six fewer runs than 2010. Worley exceeded expectations as a rookie. Let's give eight runs to Halladay, 10 Hamels, 12 to Lee and 15 to Worley. That's 45 more runs allowed.

5. Decline from bullpen/No. 5 starter.

The Phillies' bullpen was effective in 2011 with a 3.45 ERA. Jonathan Papelbon-for-Ryan Madson should be an equal exchange but some of the other guys may not match their 2011 numbers. Same goes for spot starter Kyle Kendrick (3.22 ERA). Plus there's the loss of Roy Oswalt to consider. Let's give 15 more runs to the bullpen and 15 more from the No. 5 slot in the rotation.

So we're losing 50 runs on offense and adding 75 runs on defense.

That gives us 663 runs scored and 604 runs allowed ... that's still good for 88 wins.

Is that a conservative worst-case scenario? No, it's actually a pretty ambitious decline of 14 fewer wins. Since 1996, 17 teams have won 100 games. Their average decline the following season is minus-6.6 wins. The five biggest declines:

2001-02 Mariners: -23 wins

2005-06 Cardinals: -17 wins

1998-99 Yankees: -16 wins

1999-00 D-backs: -15 wins

2009-10 Yankees: -8 wins

1999-00 Braves: -8 wins

It's no surprise that the 2001-02 Mariners and 1998-99 Yankees suffered big declines considering they were coming off seasons of 116 and 114 wins. The 2005-06 Cardinals declined almost exclusively due to a big increase in runs allowed, 634 to 762 (Jason Marquis stayed in the rotation all season despite a 6.02 ERA). That team won the NL Central with just 83 wins and then the World Series. The 1999-00 Diamondbacks had a big drop in offense; Matt Williams and Jay Bell combined for 73 home runs and 254 RBIs in '99, 30 and 115 in 2000.

Anyway, the bottom line: This is how good Halladay, Lee and Hamels are. This Phillies can lose Utley and Howard for half the season and still rate as the favorites in the NL East.

Follow David Schoenfield on Twitter @dschoenfield.