The guy at the top of the depth chart is the one to beat.

He's the marked man, the player who has the spot everyone else at the position craves.

Yet for a starter, there is a balance of responsibility. He is responsible for maintaining commitment and a sense of competitiveness among the rest of the players at that position. Sometimes, the roles are dynamic.

Nobody knows this better than Zack Mills and Michael Robinson. Mills, the starting quarterback heading into tomorrow's Blue-White game, has the bullseye on his back with second- and third-string quarterbacks Robinson and Chris Ganter working for the job.

"Of course I'm pushed by Mike," Mills said. "He's come along very well. That's how it is, the second guy is supposed to push the first guy and the third guy is supposed to push the first and second guy."

Last season, Mills saw the vast majority of playing time, starting all 12 regular season games as well as the Capital One Bowl in January. Robinson typically saw sporadic action, and was also put in when the Nittany Lions had large leads.

"He's improved tremendously just throwing the football," Mills said. "When he came into the game last year, he was either going to run the option, a quarterback counter, or a quarterback draw. He's worked really hard in the winter and really hard in the spring."

Penn State football coach Joe Paterno said in his spring press conference that he felt Robinson has all the physical tools to step into the starting role, but made it clear that Mills has the job. Paterno has tried to keep Robinson focused to fight for the spot. Mills has been the catalyst for the motivation.

"I came as a quarterback and Coach Paterno wants to give me every chance to show that I am a quarterback," Robinson said. "I wouldn't say there's a job opening, but I'd say there's a chance. The coaches have been fair and up front with me. I can only try my hardest and see what I can do."

Mills and Robinson have a mutual respect for each other and are friends on and off the field.

"There really has been business as usual," Robinson said. "We're always constantly helping each other out. The only thing different this year is that you can sense this year that we're going after each other."

The situation the two are in is unique. At another university, Robinson would be able to be the starter, which Mills realizes. Then again, a team can never have too much talent.

"It's a very unique situation," Mills said. "It's a tough situation too. We pretty much have three [quarterbacks]. I think Chris [Ganter] is prepared to come in and play too. Nowadays, how physical the game is, we're in a lucky spot. Three players can't go in and play the same position. It's kind of frustrating."