Ever since the Phillies acquired Roy Oswalt in a mid-season trade in 2010, their team strategy was a simple one - pummel the other team with starting pitching three out of every five starts. If the team wins most of those starts and essentially treads water in the others, it will be in great shape.
And that's what happened in both the remainder of 2010 and all of 2011. The results are quite stark, in fact. In 2010, the Three Aces of Roy Halladay, Cole Hamels, and Oswalt combined for 78 starts. The Phillies won 64% of those starts, or 50 games. In the 84 games not started by one of the Three Aces, the team won at only a 56% clip, or 47 games. Thus, over the course of the season, the Phillies won 8% more games when their Three Aces started. The following chart shows these results:
In 2011, the difference was even more stark. The Three Aces of 2011, now Halladay, Hamels, and Cliff Lee, combined for 95 starts, and the Phillies won 64 of those games, or just over 67% of their starts. In the remaining 67 starts, the Phillies won only 38, or just under 57% of the games. The Three Ace difference in 2011 was over 10%.
As a team built around the pitching of three number one starters, the Phillies were doing exactly what they had to do in 2010 and 2011 - winning the games they had the best chance to win.
Unfortunately, as with most other things about the team this year, the season has not gone according to plan in this department either. While the Phillies are still outperforming in games started by the 2012 Three Aces compared to games started by the rest of the pitching staff, the level of success in the Three Aces starts is nowhere near comparable and the outperformance is nowhere near as stark.
The Phillies are not even winning at a .500 clip in games started by Halladay, Hamels, and Lee this year. Moreover, their performance in those games is only marginally better than their performance in games started by all other pitchers.
This is not a path toward success given the composition of this team. And, although the team has been better so far in the second half in games started by the Three Aces (3 wins, 3 losses, .500 winning percentage), they've been even more successful in games started by the rest of the team (3 wins, 1 loss, .750 winning percentage).
To state the obvious, the Phillies need to win more games, regardless of who's starting them. But when the team is constructed with Three Aces but isn't winning games started by them at any significantly different rate than the other starters, the team is in trouble.