ESPN: What's wrong with Mariano Rivera's cutter?

ESPN's Stats & Information team examines the recent struggles of Mariano Rivera.

Yankees closer Mariano Rivera has had some significant issues in his last two appearances for the Yankees and one of the reasons for this is an issue he’s having with his trademark pitch. 

As Bill Chuck noted a few weeks ago, in a piece on BaseballAnalytics.org, that Rivera’s cutter was not as sharp as it had been in previous seasons. 

Source: ESPN.com (Mark Simon)