It's clear that Pat Burrell and Raul Ibanez are awful left fielders. By John Dewan's metrics, they were the two worst left fielders in baseball for the last two years. So let's compare them where any difference might show up - in their offensive stats:
|2008 OBP v. lefties||0.406||0.368|
|2008 SLG v. lefties||0.545||0.497|
|2008 OBP v. righties||0.351||0.353|
|2008 SLG v. righties||0.492||0.470|
|Career OBP v. lefties||0.410||0.322|
|Career SLG v. lefties||0.540||0.411|
|Career OBP v. righties||0.352||0.355|
|Career SLG v. righties||0.467||0.494|
What's clear from this chart is that Burrell and Ibanez are pretty similar hitters with a slight advantage to Burrell. But, there are two big differences between the two. First, Ibanez is 4 years older than Burrell. That's significant, as the age difference matters more for two players in their 30s than in their 20s.
But the second difference is the big one. Look at the platoon splits for the two players. Ibanez actually hit better against lefties this year than against righties (although still much worse than Burrell), but his career numbers show that's an aberration. Over his career, Ibanez has a .733 OPS against lefties, compared to Burrell's .950 OPS. Yes, Ibanez is better against righties than Burrell, but not by much - Ibanez's .849 OPS to Burrell's .819 OPS.
The huge problem is that Ibanez is being inserted into a lineup that already has a big disadvantage against lefties. Chase Utley and Ryan Howard have platoon splits, with Howard's being huge. Pat Burrell's dominance against lefties buffered that problem a bit. Now, with Ibanez in the lineup with Howard and Utley, the Phillies are that much weaker against lefties. They'll hit righties marginally better, but that was never the team's problem.
The bottom line is that Ruben Amaro's first big free agent has these effects:
- it does nothing to solve one big problem (left field defense)
- it marginally improves a non-problem (hitting against righties)
- it significantly worsens the team with respect to a serious problem (hitting against lefties)
- it makes the team older
- it gives up a first-round draft pick (thanks dajafi for reminding me in the comments)
I'd say that adds up to a very troubling start to Amaro's career and a big problem for the Phillies offense.