Who is the next Mo?

Here is something that we all know, replacing Mariano Rivera is impossible. Rivera has been the most
dominant closer in the league over the past 17 years, and it isn’t particularly close. Mo is 42 now and is
apparently leaning towards retirement after this season (contract is up after 2012) in a major way.

To see just how dominant Rivera is, consider his pitch repertoire. He throws a combination of a fastball and
cutter, leaning towards the cutter almost 84% of the time. According to PitchFx pitch values /100, Rivera’s
Fastball and Cutter measured at 1.13 and 2.13 respectively. The weighted average value of these pitches,
because Rivera uses his cutter far more frequently, is 1.97. As a disclaimer, these statistics were only kept
since 2007, so we are missing out on many of Rivera’s prime years.

I took all of the relievers that were eligible since 2007 and looked at their two most frequently used pitches,
and no one comes close to Rivera. Rivera’s weighted average value of his two pitches is 2.56 standard
deviations above the mean; the next closest is Heath Bell with 1.54 standard deviations above the mean. In
layman’s terms, Mariano Rivera is beyond a stud. His cutter, with a value of 2.13, is the third highest rated
pitch amongst the eligible relievers. Ryan Madson’s change-up (2.46) and Francisco Rodriguez’s change-
up (2.91) were both higher, but both have a usage rate under 28%. Rivera uses his cutter almost 84% of the
time, and hitters still can’t do anything against it.

In case anyone was wondering, Nick Masset is the most useless reliever on the list, with a combination of a
crappy fastball and very crappy curveball.

So who replaces Rivera? As Alex pointed out, Cashman prefers to keep his bullpen cheap, so I don’t expect to see another Soriano signing any time soon. Not to mention, I hope the “closer” role becomes extinct fairly soon.

Internally, for the time being, the Yankees are looking at Rafael Soriano, David Robertson, Joba
Chamberlain, Cory Wade, Boone Logan and recently signed, but currently injured, David Aardsma.

In looking at the top two pitches for everyone, Soriano is the only one close with a good fastball-slider
combination. Robertson has a good fastball, but still has to develop his curveball. He is only 26, so that is
not outside of the realm of possibility. Joba and Logan both have weak fastballs with good sliders, but are
26 and 27 respectively, so they have some time to develop as well.

Not only does Rivera have two nasty pitches, but his command within the zone is un-paralleled by the other
Yankee pitchers. Mo’s K/BB is 4.04; Soriano is next with 3.37, Chamberlain and Robertson both with
about 2.55 and Logan with 2.05.

At this point, Soriano, 32, seems like the candidate for a poor man’s Mariano, but he slips when it comes
to keeping the ball in the ball park and on the ground. Rivera’s HR/9 is .48, Soriano is at .89. Mo’s gets
ground balls 53.2% of the time, while Soriano is at 31.4%, and as Alex said in the last article, those
numbers do not cut it in Yankee Stadium.

As much as Mike Francesa will fight it, Rivera’s replacement, at least internally, is going to be David
Robertson. His GB% is 41.4, which is low, but his HR/9 throughout his career is .58. As a 26 year old, he
has time to develop his curveball and work on his walk rate.

Joba and Logan both have slightly better GB rates, but they allow too many home runs with similar, if not
worse command.

Robertson strikes out a ton of people and keeps the ball in the park. No one will equal Rivera and it isn’t
worth it to try. Robertson is a relatively cheap option that can continue to develop while already performing
at an above average level.

- Ian Boehme