Laugh away at Tony Pena Jr.’s batting average or on-base percentage.  Slap your knee to the tune of his slugging percentage, which barely broke the Mendoza line last season—a marker normally reserved for batting average.  But make no mistake, Tony Pena Jr. might be the most important player at the Royals’ complex in Surprise, Arizona this year. 

Accurately measuring players’ Spring Training performance has confounded scouts, managers and fans for decades.  So much so that fans normally tune them out entirely.  Is Alex Gordon hitting the ball hard?  Well, he hit it pretty hard in Spring of ’07.  Hochevar is locating his fastball?  Runelvys Hernandez did that in the Spring not so long ago, too.  There’s just no way to know whose performance is a legitimate sign of the season to come, and whose exists in isolation as players around the major leagues stretch, warm up, and work out the kinks in their swings and wind-ups. 

That’s where Pena comes in.  Royals staffers have taken to calling him “the human barometer.”  For instance, yesterday both Mark Teahen and Mike Jacobs had good days at the plate.  Yet so did Pena.  Have a look at Dick Kaegel’s notes from the game:

“Royals at the plate: Mike Jacobs and Mark Teahen paced the offense. Teahen finished with a pair of homers, a double, two RBIs and four runs scored, while Jacobs contributed a two-run shot. Tony Pena Jr. also had a nice day at the plate with three singles, driving in a run with his first knock. Willie Bloomquist added a two-run single in the seventh.”

When asked whether fans should get excited about a possible return to 2006 for Mark Teahen based on yesterday’s game, a Royals official who wishes to remain anonymous brushed it off.  “I mean, I’m not saying it won’t happen, but look, TPJ had three hits too.  He drove in a run.  Heck, you don’t have to ask me, what does that tell you?”

And, in a nutshell, that is why Pena is getting so much playing time.  Pena tells Royals evaluaters which stats to take seriously.  It’s not a perfect system by any stretch.  If Jacobs hits a bomb and Pena strikes out four times, for example, you still can’t say with certainty that Jacobs had a good day.  But if Pena hits the ball, even once, on the same day other players do, you can keep those numbers out of your Spring Training calculator. 

“He’s been monumentally important for us, in terms of our ability to guage how the other guys are doin’” said manager Trey Hillman, spitting what could have been tobacco juice, but might have been just regular spit.  One thing is sure, the Royals are leaving no stone unturned this Spring.