Orioles starters offer few sure things

The number of reasons to doubt the 2013 Orioles is as long now as it was last year -- the one-run games, the extra-inning wins, the improbable performances, there are all sorts of reasons to wonder how they could repeat any of it. But the rotation is one area where the O’s don’t need a repeat performance, they need massive improvement -- last season’s starters produced a collective Fair Run Average of 4.77 (a Baseball Prospectus metric accounting for their expected runs allowed), the worst of any team that reached the postseason, ranking just 20th overall in the major leagues.

A lot of that was the product of turnover in the rotation, as manager Buck Showalter and GM Dan Duquette sorted through alternatives to Jake Arrieta, Brian Matusz and Tommy Hunter after they all struggled. Wish away that sort of churn, and it’s easy to see where the Orioles themselves might expect improvement if their better options from among last year’s in-season fixes stay healthy. If Chris Tillman repeats what he did for them in the second half, when he posted a 2.93 ERA, that’s another major improvement. If you think Wei-Yin Chen and Miguel Gonzalez can reliably deliver winnable starts, maybe last season’s run of keeping close will be repeated, but Gonzalez almost literally came out of nowhere. Getting a full year out of Jason Hammel would be a good thing if you think he can repeat last season’s first-half breakthrough as a true sinker-slider power pitcher. That’s especially critical, because he was the lone productive regular with a strikeout rate significantly above league average (23 percent, against MLB’s 19 percent clip last year).

Unfortunately, there isn’t a ton of consensus to be found among projection tools about what to expect from the Orioles’ rotation: ESPN Insider’s Dan Szymborski’s ZiPS system is somewhat optimistic about Hammel, Chen and Tillman all being useful big-league starters, but BP’s PECOTA isn’t high on Tillman or Hammel. Bill James’ forecasts loves Miguel Gonzalez’s shot at being even better this time around, but ZiPS and PECOTA don’t offer any endorsements. Given that all of them lack consistent track records at the major-league level and -- except for Hammel -- none of them have been fairly defense-dependent, you can understand why there’s so much room for disagreement across systems, and why their performances might not be all that much under their own control.

Beyond that questionable quartet, Showalter is not confronted with any easy choices. On paper, 2011 All-Star Jair Jurrjens might work -- if Jurrjens’ knee heals, and perhaps if he also gets a lot of help from an Orioles defense that ranked in the top 10 in Park-Adjusted Defensive Efficiency. Zach Britton had his moments down the stretch, but concerns persist about the health of his arm. Later this season, Japanese finesse lefty Tsuyoshi Wada will be back from Tommy John surgery.

Mull that over, and the temptation to get top prospect Dylan Bundy to the majors seems obvious. But will the O’s be as disciplined with Bundy as the neighboring Nationals were with Stephen Strasburg? We’ll see, especially if any early season frustrations from their initial front five start boiling over.

Christina Kahrl covers baseball for ESPN.com. You can follow her on Twitter.