The Cubs have made a few moves this off-season to try and stay in the top of the NL Central. In 2010 they fielded a very young bullpen with impactful pros and cons. Here we dissect the current bullpen and it's potential within the NL Central.
Carlos Marmol is one of the games top closers. He set a major league record in 2010 by striking out 15.99 batters per nine innings as a reliever. He was periodically wild, hitting or walking 60 batters but he only allowed 40 hits all year and only one of them a home run. Carlos has a very effective fastball and slider and will likely lead the division and the National League in saves.
The Cubs re-signed Kerry Wood for 1.5M which is a steal considering his effectiveness last season with the Yankees (1.23WHIP, .69ERA in 26 innings). Wood turned down more money to return to the team that brought him up. Last season lefty Sean Marshall was the 8th inning bridge to Marmol and he was incredibely effective with a 1.11WHIP & 2.65ERA in 74 innings. I don't know which one of these two will handle 8th inning duties but between the two of them they'll lock up the 7th & 8th effectively.
The Cubs used 15 other relievers in 2010 with an average age of just over 26. The most effective of those was probably 24 year old James Russell. And I determine his 'effectiveness' relative to the rest of the pen. Here are his numbers: 49 innings, 1.34 WHIP, 4.96 ERA and 11 home runs allowed. 23 year old Andrew Cashner was also subjectively effective: 54 innings, 1.56 WHIP, 4.80 ERA & 8 home runs allowed. Scott Maine did quite well (1.07 WHIP, 2.08 ERA) but he only threw 13 innings and I don't think we can predict such a small sample size to replicate.
John Grabow drastically underperformed last season with a 7.36 ERA. He has been much more effective in the past and I expect him to have a more positive impact in 2010.
Really, the rest of the bullpen success rests on the hope that the staff will improve. Many could argue that in 2010 the young age of many Cubs relievers contributed to their poor performance but I can't expect one season to lead to the amount of improvement this pen needs to be competetive. As it stands, the back end of the pen is solid, one of the best in the NL. Before the 7th inning though, the Cubs will be gambling with nearly every reliever they put on the mound.
The Cubs bullpen as a whole is still risky. It would be in their best interest to sign a seasoned reliever with proven numbers before Spring Training to ensure improved play from the pen.