In a season that has mostly sucked it seems appropriate to pay tribute to those who helped them suck even more than they would have otherwise. I haven't looked this over so I'm doing the work as I write along. We'll start with the position players and if I feel like I'll do one for the pitchers tomorrow.
Joe Mather has had a spectacular season. His .210/.257/.326 batting line is good for a .255 wOBA. Thanks to -9 UZR and below average baserunner he's been worth -1.5 fWAR and has had only 242 plate appearances. Mathers has an even more impressive -2.0 rWAR though BPro's WARP has him at a measly -0.9.
Josh Vitters career is off to a fabulous start. It's been so good the Cubs are likely to shut it down for good. Yes, we're back to that. Vitters has opposite-of-hit .113/.171/.196 and that's good for a wOBA of .170. His fWAR is -1.4. Consider this, Mather has had 242 plate appearances and has been worth -1.5 fWAR. Vitters has 105 PA and has been worth -1.4.Although Mather has been horrible at the plate, his wRC+ is a solid 57 points higher than that of Josh Vitters (-5). Josh's rWAR is -1.3 and his WARP is a team worst -1.4. Mike Trout is 11.7 rWAJV.
Although he only played in 13 games for the Cubs, Marlon Byrd has the 3rd worst fWAR at -0.8. His rWAR is 4th worst at -0.4 and his WARP is 5th worst at -0.5.
Then there's Steve Clevenger who can't even be close to replacement even though he has the advantage of being a catcher. His fWAR is -0.7, rWAR -1.0 and his WARP is -1.3.
Honorable mention: Blake. The Cubs would have been nearly a win better if they didn't have any player named Blake. Blake Lalli and Blake DeWitt combined had -.8 fWAR, -.6 rWAR and -.4 WARP in 46 plate appearances.
The average of the 3 WAR's barely gives Joe Mather (-1.5 WAR) the lead over Josh Vitters (-1.4). It's actually -1.46 for Mather and -1.43 for Vitters so these next 4 games are critical. Then again, Mather has more than twice as many PA as Vitters so it's really not at all close. If Vitters had the playing time that Mather has, he might have -3.3 WAR.