With the way the game has changed over the past few decades, relief pitching has become a substantially more important part of baseball.
In the age of innings limits, pitch counts, and match-ups, starters aren't pitching as deep into games as was once the norm. A bad bullpen can turn a decent team into a bad one, and a great bullpen can solidify a good team as a serious playoff contender.
For the first half of the season, the New York Yankees struggled with consistency once the starting pitcher exited the game. Aside from Mariano Rivera, there was no reliever that inspired much confidence in coaches, teammates, or fans.
Chan Ho Park got off on the wrong foot and never righted himself. Joba Chamberlain was handed the main setup gig and quickly lost it. David Robertson looked nothing like the guy he was in the 2009 playoffs. Sergio Mitre and Chad Gaudin were both serviceable long men, but nothing special.
The Yankees were burning through relievers left and right, and we saw a few cameos from the likes of Jonathan Albaladejo, Romulo Sanchez, Mark Melancon, and Ivan Nova.
But the volatile nature of relievers came into play and changed the course of the Yankees bullpen sometime in June. One by one, the New York's relievers started putting it together.
After posting a 7.31 ERA in his first eighteen appearances, David Robertson fixed something and has been a reliable late-inning strikeout machine since June rolled around. In his last 23 appearances, he's allowed five runs in 23.2 innings (1.92 ERA) with 28 strikeouts.
Boone Logan held a respectable ERA of 3.93 when he was optioned to Triple-A in favor of Dustin Moseley, but his peripherals were not as impressive. He had a 13:12 strikeout-to-walk ratio and had allowed 20 hits in 18.1 innings.
He spent two weeks in Triple-A and obviously figured something out as he's allowed just one run (1.04 ERA) and three hits in ten games since being recalled. He has also improved his K:BB ratio, having struck out eight and walked only one in 8.2 innings.
Joba Chamberlain went through a stretch from July 10-25 in which he allowed runs in four of five outings and was relieved of his eighth inning duties. Since then, he's tossed 7.1 scoreless innings, allowing two hits while walking three and striking out six.
All six of those appearances have come against divisional foes Tampa Bay, Boston, and Toronto. There's still improvements to be made, but there has certainly been progress.
The biggest wild card of all in regards to the New York bullpen could be trade deadline acquisition Kerry Wood. Cleveland was more than willing to almost give away their high-priced veteran reliever, who had alternated bouts of ineffectiveness with stints on the disabled list.
The Yankees decided that his still electric stuff was worth a shot and acquired him to provide another late-inning option for Joe Girardi. Having posted a 6.30 ERA in 23 games with Cleveland, Wood has looked marginally better since switching his Cleveland duds for Yankee Pinstripes.
In 4.1 innings, Wood has allowed only one run (coming on a solo home run), while issuing three walks, and striking out seven. He hasn't been perfect, but he's been better and the Yankees believe they can continue to harness Wood's arsenal to make him a weapon late in games.
As unpredictable as relievers are, with Mariano being almost the only exception, the New York relief situation could change over night. But considering the recent improvements made by the current relievers, and with the prospects of healthy returns from guys like Al Aceves and Damaso Marte, the bridge to Rivera is looking increasingly more secure.