The broad parameters of the Yankees catching competition are by now well-known. Francisco Cervelli and Chris Stewart are the favorite. Austin Romine can win the job, but only if he clobbers the ball all spring.

Since hitting a round ball with a round bat with any consistency during spring training is a difficult thing – especially for a catcher who has to worry about, you know, catching – Romine is considered on the outside looking in. But manager Joe Girardi still has to determine which of the other two, Cervelli and Stewart, will get the lion’s share of playing time.

How will he do that?

“I don’t think you’re going to get too caught up with what they do offensively as much as how they’re handling our staff,” Girardi said. “Because as a catcher, a catcher usually gets less at-bats than a position player. Because you’re not ready to catch as much.

“I’ll watch their at-bats, to see the quality of their at-bats. But for me, the defense is the No. 1 thing.”

For fun, here are the projections from Brian Cartwright’s Oliver system for Cervelli and Stewart. We’ll compare them with Russell Martin’s production in 2012.

Cervelli: .242/.319/.360, .302 wOBA
Stewart: .243/.311/.355, .294 wOBA
Martin: .211/.311/.403, .316 wOBA

The dropoff in wOBA isn’t nearly as dramatic as one would expect. That because both Cervelli and Stewart can take the occasional walk. Cervelli walked in 9.4 percent of his plate appearances in Triple A last season; Stewart took a free pass in 6.4 percent of his chances in 157 plate appearances.