Here are each players career, major league splits:
Matt Diaz:
| Split | PA | HR | ||||
|---|---|---|---|---|---|---|
| vs RHP as RHB | 849 | 14 | .269 | .327 | .382 | .710 |
| vs LHP as RHB | 797 | 29 | .335 | .373 | .533 | .907 |
Provided by Baseball-Reference.com.
| Split | PA | HR | ||||
|---|---|---|---|---|---|---|
| vs RHP as LHB | 533 | 17 | .248 | .302 | .420 | .722 |
| vs LHP as LHB | 57 | 0 | .132 | .158 | .151 | .309 |
Provided by Baseball-Reference.com
| Split | PA | HR | ||||
|---|---|---|---|---|---|---|
| vs RHP as LHB | 1442 | 50 | .272 | .336 | .461 | .797 |
| vs LHP as RHB | 490 | 9 | .256 | .321 | .373 | .694 |
Provided by Baseball-Reference.com
| Split | PA | HR | ||||
|---|---|---|---|---|---|---|
| vs RHP as RHB | 1145 | 20 | .261 | .313 | .377 | .690 |
| vs LHP as RHB | 510 | 13 | .289 | .363 | .435 | .798 |
Provided by Baseball-Reference.com
Who is the best against right handed batters? From these numbers, it's Doumit. However, the flaw in all of this is that John Bowker has not had as much time in the big leagues as the rest of these guys. He has less than 600 plate appearances in his career, so we can't really get a good grasp of his big league hitting ability. His career minor league line is .303/.370/.501, with very good success against righties, so that shows some upside. If Bowker continues to progress, he could be much closer to Doumit in terms of hitting right handed pitching. He is also a better defender than Doumit, so he would probably get the nod from me on Opening Day. However, there is something to be said for Doumit. Most Pittsburghers are extremely tired of him and just want him to leave, but you can't ignore .797 OPS he's posted against righties in his career. That's very good for a catcher, not as good for a right fielder, but it definitely is good enough to earn some playing time there for the Pirates next season, if he's still on the team.
With that said, if both Doumit is still on the team come April, I would give Bowker most of the starts in right field with right handed pitchers on the mound for the first month or two, and see how it goes. If he struggles, I'd find more playing time for Doumit there. Bowker has more upside overall, so he would be my guy.
Who is the best against left handed batters? It's Diaz, and it's not close. Milledge has put up decent numbers against lefties in his career, but .289/.363/.435 in not a lot of playing time doesn't match up to .335/.373/.533 in a bunch of playing time. This one doesn't even need discussion with Milledge not on the roster anymore, but it definitely shows that the Pirates made the right move in losing Milledge and picking up Diaz.
If I were making the lineups, I would also implement a platoon at first base between Garrett Jones and Steve Pearce. Now I'm still hoping more moves are made so we can get better than we are right now, but if the season started tomorrow, and I was the manager, my lineups would look like this:
Against a right-handed pitcher:
1. Andrew McCutchen
2. Jose Tabata
3. Neil Walker
4. Pedro Alvarez
5. Garrett Jones
6. John Bowker
7. Chris Snyder
8. Ronny Cedeno
9. Pitcher
Against a left-handed pitcher:
1. Andrew McCutchen
2. Jose Tabata
3. Neil Walker
4. Pedro Alvarez
5. Steven Pearce
6. Matt Diaz
7. Chris Snyder
8. Ronny Cedeno
9. Pitcher
Now, substitute J.J. Hardy for Ronny Cedeno and you've got a decent looking lineup, and a potentially dangerous one if McCutchen, Tabata, Walker, and Alvarez continue to improve.