Three keys to the Cubs' recent success

CHICAGO -- If you haven't noticed, the Chicago Cubs are playing better baseball lately, winners of four of five games, including a three-game sweep of the New York Mets this week. Here are three keys to their recent success:

The bullpen

This is reason No. 1 because they've been asked to hold on to some precarious leads while eating up a lot of innings the starters have left on the table. Consider the Mets series: How many sweeps are there when a team's bullpen has to come into each of the three games starting in the sixth inning or earlier? Usually there's a breakdown somewhere, especially with the Cubs' recent history. Not this week.

All eight relievers threw well against the Mets, giving up two runs -- on one home run -- while locking down all three games by 2-1, 5-4 and 7-4 finals. The Cubs scored two in the bottom of the eighth Thursday or else it would have been three one-run wins in a row. They were awful in that category just a few weeks ago. The bullpen has a 1.86 ERA over the past 22 games.

"It's not necessarily that they've sparked the run, it's that they've contained and minimized damage," manager Rick Renteria said. "As an offense, you can breathe a little bit because it's not going to get out of hand."

Add-on runs

Over the past couple of seasons, the Cubs have simply stopped scoring, even after taking early leads in games. Not so much lately, as Junior Lake's double with two outs in the eighth to plate two insurance runs Thursday is something that wasn't happening often. The Cubs scored two in the first inning Wednesday but won the game because of a three-run fifth. The add-on runs come when an opposing starting pitcher tires or gets knocked out early. The Cubs have won games taking advantage of both scenarios.

Role players producing

Finally, the Cubs aren't just relying on Jeff Samardzija, Jason Hammel, Anthony Rizzo and Starlin Castro. Nate Schierholtz has slowly returned to form, and Lake's big hit was much-needed for him and the team. Luis Valbuena has contributed lately, as has Chris Coghlan. Some of those players were invisible for the first two months of the season. No team can win with just a few players pulling their weight.