The very important SS battle in Seattle

I have a running dialogue with a friend of mine about Brad Miller of the Seattle Mariners: My friend, shall we say, is not a big fan, doesn't think Miller can play shortstop in the majors, and points out that he didn't exactly tear things up at the plate in 2014 (.221/.288/.365). I'm more hopeful and, while acknowledging that Miller does make too many errors, I point out that his defensive metrics aren't horrible (although still slightly below average) and that he still has potential with the bat. Over his one-plus seasons in the majors, his park-adjusted wRC+ is 95, which ranks tied for 12th among shortstops, even with his poor 2014 numbers.

Anyway, Miller is in a battle for the Mariners' starting shortstop job with Chris Taylor, who hit .287/.347/.346 in 151 plate appearances as a rookie. While Miller has some pop, Taylor doesn't have much; he went homerless with the Mariners after hitting five for Triple-A Tacoma in 302 at-bats. Taylor was a .320 hitter with a .407 OBP as he shot through the minors in two years; but Miller hit .334 with a .409 OBP as he also shot through the minors in two years.

While Miller had a .958 fielding percentage with the Mariners, Taylor actually wasn't much better at .962. The defensive metrics, however, did rate Taylor as the superior defender -- plus-4 defensive runs saved in his limited time versus minus-3 for Miller. In fact, using old-school numbers, we can see Taylor's range advantage:

Miller: 2.6 assists per nine innings

Taylor: 3.1 assists per nine innings

It's a small sample size and the numbers may be influenced by the pitchers each guy played behind, but the numbers match the eye test, that Taylor has better range.

The Mariners could keep both players -- Miller has been playing some outfield in spring training -- but Mariners beat writer Bob Dutton tweeted that the loser of the battle will be sent to Triple-A Tacoma to play shortstop, with veteran Willie Bloomquist serving as the backup infielder.

As Marc W. writes at the USS Mariner site:

The problem, though, is that this plan comes at a cost, and the M’s are finally in a position where they need to think carefully about every single decision that impacts 2015 wins. As we've talked about, the M's are projected as the favorites in the 2015 AL West race. That's the view of many projections systems (though not quite all), with ZiPS and Steamer putting the gap between the M's and the A's and Angels at around 1-3 wins. These are projections, so there's a margin of error that's several wins wide around all of these win totals. If the Angels win, it won't be a historic upset, but at the moment, knowing what we know about who's going to suit up for each team, the M's win a few more times than their rivals. For a number of reasons, this may be the M's best opportunity at playoff baseball, as the A's collection of moves sets them up better for 2016 and beyond than it does for 2015. The Angels are going to start to feel the ravages of age and attrition, but any team that's built around Mike Trout is always going to be a threat. The Rangers minus Yu Darvish are awful, but a smart rebuild could set them up for 2017 at the earliest and 2018 if Darvish heals and stays in Texas. The Astros controversial philosophy has to pay dividends at some point, right?

Bloomquist isn't as good as Taylor or Miller. Marc's essay delves into more specifics but here's the nut sentence: "Swapping one or the other out for Willie Bloomquist, the most likely replacement IF, results in a total loss of around 1.7 WAR, or about the sum total of the M’s lead over the Angels. To restate it, the M's are currently projected at somewhere between 1-2 wins better than their rivals, if constructed optimally."

There's another issue at stake: While Taylor and Miller are projected to be about equally valuable, it's possible that one player is better than the other. Maybe Taylor's defense is so much better, it doesn't matter that he won't hit for much power. Or maybe he'll add a little pop to his ability to hit for average. Or maybe he won't hit much at all. But what if Miller is a 20-homer shortstop who hits .270? Even with just adequate defense, that's a nice luxury to have. But what if his defense isn't playable?

That's what makes this such a fun battle to watch. In this day and age, teams are pretty much set heading into spring training, barring injuries. For the most part, front offices are making their talent evaluations in the offseason, as opposed to a manager and coaching staff making talent evaluations and decisions in spring training. But this is clearly a case where spring training performance is likely to determine the starter.

So this is a decision with multiple layers. Not only could the Mariners be making a mistake if they do send one guy down, but they have to make sure they pick the right guy in the first place.