Who is Rickie Weeks?

At the start of the offseason, none of us expected Rickie Weeks to be on the Mariners' radar. Robinson Cano was signed for nine more years (!) and Weeks had infamously refused to move off of second base last year. So it was a surprise to find out that the Mariners had actually pulled the trigger on the unexpected, signing Weeks to a one-year, major league contract worth up to $4 million.

Colin and Scott already covered what signing Weeks could mean for the rest of the roster. I'm here to try and figure out just who Rickie Weeks really is. Not in an existential kind of way (though his Wikipedia page mentions that he was voted sexiest baseball player in 2009). I'm trying to figure out what he might look like on the baseball diamond in 2015.

You're all pretty familiar with Weeks' story by now -- a few years of excellence followed by two years of below replacement level production and the loss of his job as the starting second baseman on the Brewers. Here are his batting lines from the last five years with his Steamer and ZiPS projections for this coming year (ZiPS have not been adjusted for his move to Seattle):

We can immediately see his overall numbers begin to dive in 2012 and bottoming out in 2013. His strike out rates and walk rates have stayed pretty steady over the last five years so I don't think his struggles are related to his plate approach. What does strike me is his steady decline in batting average on balls in play from 2010 to 2013. Between 2005 and 2011, Weeks' batting average on balls in play averaged just under .310. But in 2012, it dipped to .285 and fell to just .268 in 2013.

Batting average on balls in play is a fickle stat, requiring at least 800 balls in play to become stable for batters. Weeks hit just under 800 balls in play between 2012 and 2013 so it's possible he might have established a new talent level but then his BABIP jumped up to .355 in 2014. Let's take a look at his batted ball profile to see if we can find any rhyme or reason in the numbers.

Between 2010 and 2013, Weeks' batted ball profile stays pretty consistent. He did deal with two significant leg injuries -- an ankle injury in 2011 and a hamstring injury in 2013 -- which may have sapped some of his athleticism. But in 2014, his batted ball profile saw some significant changes. Weeks began pounding the ball into the ground at a much higher rate and popped up just once over the course of the season. A higher ground ball rate and a miniscule infield pop-up rate could lead to a much higher batting average on balls in play. I'm hesitant to claim causation since it's just one year of data but a hitter's batted ball profile stabilizes around 100 balls in play giving Weeks' new approach some credence.

The good thing is, despite hitting more ground balls, Weeks still found a way to mash home runs. He's shown an ability to post above average home run rates in his career and last year was no different. His home run rate of 17.8% was a five-year high for him so I don't think we can expect a rate that high in 2015 but I think it's safe to say that Rickie Weeks still has some power in his bat.

When I took a look at Nelson Cruz's power and how it might be affected by Safeco Field, I noted two factors that would affect his ability to hit home runs in Seattle: average batted ball distance and average home run speed off the bat. Let's take a look at Weeks' ability to hit the ball hard to see if there has been any decline.

Both his average fly ball distance and his average home run speed off the bat have stayed pretty consistent over the last five years. Not only that but he's also shown an ability to spray the ball to all fields, with power.

That's Weeks' spray chart from 2012 to 2014. Even in his two years of decline, he was spraying line drives and hitting for power to all fields.

So, for just $2 million (or potentially $4 million) the Mariners signed a useful right-handed bat who could provide some depth and insurance at a number of positions across the diamond. If Rickie Weeks' new batted ball profile sticks, we could see his batting average on balls in play return to his previous career norms while maintaining some of the pop that he is known for. Safeco will probably hurt his overall numbers a bit, but it won't hurt his power output as much as one might think. Barring any sharp decline, Weeks should continue to be a useful hitter off the bench who could also step into a starting role in case of emergency. All in all, he's a pretty great pick up for the Mariners and should be a valuable piece on the roster.