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San Francisco Giants' Buster Posey hits a two-run double off Seattle Mariners starting pitcher Blake Beavan during the sixth inning of their spring training baseball game in Scottsdale, Ariz., Sunday, March 6, 2011. Giants' Andres Torres, background, looks on. San Francisco won the game 6-1. (AP Photo/Eric Risberg)

Buster Posey stood patiently at his locker before Tuesday night's Bay Bridge Series game, getting an education on the best catching the Giants have known during their time in San Francisco.

Interesting, in that last year he gave Giants fans the same.

"Bengie (Molina), Eli (Whiteside)," Posey said when asked if he could name some of his predecessors. "Mike Matheny, Benito Santiago ... I'm leaving some out. Brian Johnson. Let me think some more."

Posey meant no disrespect, and neither do we. The San Francisco incarnation of the Giants boasts six different catching All-Stars. It has known two Gold Glove winners (Kirt Manwaring, Mike Matheny), a Sheik (Mike Sadek), a Mule (Dick Dietz) and a future Hall of Famer just passing through (Gary Carter).

But the Left Coast Giants have never known sustained greatness behind the dish. The book on Posey is that such greatness is his destiny. At some point, maybe sooner than later, we could be hailing him as the best catcher in San Francisco Giants history.

Yes, this is in part a whimsical barstool argument.

"We all know what (Posey) has done already," said Giants pitching coach Dave Righetti, an expert of sorts by virtue of nearly two decades with the team and having grown up a baseball fan in the Bay Area. "It's pretty remarkable. So there's no doubting that. To go into the other thing, the greatest, I think we'll have to wait a few years."

But there's a practical side to this discussion. When gauging the prospects of a Giants World Series repeat, it's possible they'll have to be better than they were last year. Where does that improvement come from?

It could come from slugging prospect Brandon Belt. It's easy to imagine starting pitcher Madison Bumgarner building on his rookie season. But if the conventional wisdom is correct, and Posey is just scratching the surface, his sky-high upside could be key to a repeat.

"Oh, I've already seen that," manager Bruce Bochy said when asked if he thought Posey could upgrade his game. "He's come along a long way on the defensive part. As far as the bat, he's going to be a good hitter. We just want him to continue improving. That's what you do as a player, keep working to get better. And he's doing that."

Bochy cited blocking pitches as one improvement Posey has made from last year to this. Tuesday night, a couple hours after Bochy's comments, Posey blocked a bouncing Barry Zito curve, chased it down like a third baseman bare-handing a bunt, and nailed Hideki Matsui at second base trying to advance.

Posey, who turned 24 earlier this week, considers year-over-year improvement part of his job description.

"You always strive for more consistency," he said. "It's a long season -- always grinding on at-bats, never taking a pitch off, just trying to make the most of whatever situation you have each day."

He already has a couple skins on his wall that no other San Francisco Giants catcher can match. One is the sparkly ring he and his teammates will receive on April 9. The other is the Rookie of the Year paperweight he'll receive the day after that.

The body of work standards will take a little longer to chase down.

"You've got to start with (Tom) Haller, right?" Righetti asked. When it comes to home runs, you do. Haller had the best season (27 in 1966) en route to the best career total (107) by a San Francisco catcher.

Dietz had the best RBI season, 107 in 1970. Bob Brenly has the most (327) for his Giants career. (Yes, we realize Brenly played other positions, as has Posey. But we're not splitting the hairs that fine here.)

Posey's 18 homers in 2010 marked the 11th time a San Francisco catcher had hit that benchmark; likewise his 67 RBIs. His .305 average is a record for San Francisco catchers based on a minimum of 400 at-bats.

So he's already ankle-deep into the team's record book, with the physical gifts to suggest he could commission a complete rewrite before he's done. But there we go again, putting the superlatives before the horse.

"There have been some good ones," Posey said, asked about his organizational ancestors and how he ultimately might be ranked among them. "Luckily I don't have to concern myself with that."

He's got more important things on his plate.

Contact Gary Peterson at gpeterson@bayareanewsgroup.com.