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Why Jerry Signed Marc Rzepczynski

Hint: He’s pretty good against lefties.

MLB: Seattle Mariners-Media Day
The last thing lefty hitters see before they inevitably walk back to the dugout.
Rick Scuteri-USA TODAY Sports

When the Mariners signed Marc Rzepczynski (aka Scrabble) this offseason, many fans were wary of his contract, and rightfully so. A guarantee of $11 million over two years is a steep price to pay for any relief pitcher, let alone a lefty specialist. However, in 2016, the Mariners bullpen was one of the worst in the MLB against left-handed hitters. Southpaws in the Mariners pen tallied an FIP of 4.19 against lefties over the course of the year, and things were particularly bad after Mike Montgomery was traded to the Cubs on July 20th. From that point on, Mariner lefties posted a 5.72 FIP against left- handed hitters, good for 27th in the league. This is obviously an area where the Mariners have a lot of room of improvement in 2017, and with Charlie Furbush out for another year, there really wasn’t a viable in-house solution present. To fill the void, Jerry turned to reliable lefty killer, Marc Rzepczynski.

Let’s take a look at what makes Rzepczynski so appealing as a potential lefty specialist. Why would Jerry be willing to spend so much on Rzepczynski when he has been so unwilling to dabble in free agency in the past? The obvious answer is that Rzepczynski has been one of the best at getting lefties out since he entered the league in 2009. Of left-handed pitchers totaling more than 100 innings against left-handed hitters since 2009, Rzepczynski ranks 7th in FIP and boasts a wOBA of .266. With both of these numbers, he finds himself in some pretty impressive company.

However, some people are concerned that Rzepczynski’s dominance is behind him. In 2016 his BB/9 ballooned to 5.48, well beyond his previous career high of 4.24 in 2010. While this could be a sign of aging for the 31-year-old lefty, it seems more likely it was due to a change in pitch repertoire. As you can see on the table below, Rzepczynski started throwing his changeup at a much higher rate in 2016 than he did in any year since 2010, his previous career high BB/9.

Here is where his changeups were located in 2017.

As you can see, most of the changeups he threw were outside of the zone, and what’s even more interesting for the purpose of his role with the Mariners is that he didn’t throw a single one to a left-handed hitter. This is significant because his BB/9 splits are insane. In 2016, his 1.95 BB/9 to lefties was under his career mark of 2.45. Against righties he ran a 10.35 BB/9 compared to 5.30 over the course of his career. Looking at these splits, it’s very easy to make the case that Rzepczynski’s increased use of his changeup has contributed to his loss of command against righties. In 2016 he also faced more righties than he had in any year since 2011, so it’s no surprise that his overall numbers were a little less impressive than in the past.

Luckily for the Mariners, they only need him to be good against lefties. Looking at his 2016 numbers, there is little to suggest that he will be anything but the lefty destroyer he has been for the duration of his career. Take a look at his career numbers against lefties.

In 2016, everything was aligned similarly with what he has done in the past, and that is really all the Mariners need him to do in 2017. Also, can we all just appreciate that K/BB ratio in 2013. Holy shit. Rzepczynski does not need to be a guy the Mariners give the ball for the duration of an inning. He just needs to be able to come in and mow down lefties like he has done for his whole career.

Whether you think his role is worth $11 million over two years or not, there is no denying that in 2016 the Mariners were missing a guy who could come in and get a good lefty out in a tough spot. Rzepczynski fills this void immediately as a proven lefty killer who has no signs of stopping any time soon. Keep it up Marc, maybe someday I’ll be able to spell your last name from memory. Goms.