Four of the six arbitration-eligible Giants players settled with the team on the first day that arbitration figures could be exchanged.

So you may wonder why then did Andres Torres and Javier Lopez not settle.

The answer is simple: Age.

Cody Ross is 30, Jonathan Sanchez is 28, Ramon Ramirez is 29, Santiago Casilla is 30.

Javier Lopez is 33. Andres Torres will turn 33 on Jan. 26. Lopez and Torres have fewer years of earning potential, and need to be paid now.

The way the arbitration process works is simple enough. A team will look at a player and figure out what would be a reasonable salary, then offer an arbitration figure that is less than that. The player does the same, except the player will offer a figure that is higher. Then when the two teams come together, they’ll find a middle-ground figure that is close to what each side figured was a reasonable salary.

If the two sides don’t come together on an agreement, it’s because one side — or both — think they can make a strong case for their arbitration figure.

With Lopez, it’s a case of making up for lost time.

Lopez spent much of the early part of his career making small splashes in the majors with the Rockies, Diamondbacks and Red Sox from 2003-2007.

It wasn’t until 2008 that he started making some money through arbitration, making $840,000 in 2008 with the Sox and $1.35 million in 2009.

But in 2009, he was designated for assignment by the Red Sox and eventually optioned to the minors, where he spent the bulk of 2009.

This had an adverse effect on Lopez’s earning potential by limiting his service time. When he was released by the Sox after the 2009 season, it took him out of the arbitration process.

He signed with the Pirates for $775,000 in 2010. And while he had a solid season with the Pirates and Giants, he finished the season five days shy of having enough service time to be eligible for free agency.

The Giants offered Lopez $2 million in arbitration. Lopez countered with $2.875 million. The Giants will argue their number is closer to what other middle relievers are getting in arbitration. Lopez will likely point to his service time and argue what other middle relievers are getting in free agency.

We’re guessing the Giants were hoping to settle around $2.2 million, while Lopez was looking for something in the area of $2.6 million. Look for the two sides to settle around $2.4 million.

Now Torres is 33. And because he spent so much of his career as a journeyman minor leaguer, he has never earned more than $426,000 in a season. So he’s due a big raise, whether he earns what the Giants offered ($1.8 million) or what he proposed ($2.6 million).

That fact means the Torres probably feels he’s got nothing to lose, and much to gain.

This is his first go-around in the arbitration process, meaning he won’t be eligible for free agency until after the 2013 season, when he’ll be heading into his age-36 season.

The McCovey Chronicles has a clever post about the Torres arbitration process. To read it, click here.

Bottom line here is that the Giants were probably hoping to settle at $2 or 2.1 million. Halfway is $2.2 million, but the Giants should offer Torres an early birthday present and give him an offer of $2.35 million and call it good.