FORT LAUDERDALE, Fla. -- You can never do enough due diligence. A year ago, when the Orioles began pondering a contract extension for second baseman Brian Roberts, they relied on number-crunching and statistical analysis of an advanced nature to help set fair expectations for his performance over the life of the deal.

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That endeavor largely had to do with how offensive players of his type tend to age, a case study that used seven decades of baseball history as its backdrop and systematically eliminated some ill-suited matches.

In the end, the Orioles were comfortable enough to offer him an extra year than they had originally anticipated, a fact many felt was key when Roberts signed a four-year deal worth $40 million Feb. 20. Now, with the end of that contract standing five seasons away, both sides are free to talk about the process and the end result.

"I think [historical trends are] part of the equation," said Andy MacPhail, Baltimore's president of baseball operations. "It's not the major part of the equation, which would be the individual and your knowledge of them and their work habits. But you do try to look at industry experience. When you go through your checklist of things, you try to give yourself the chance to make the best decisions. One of those things is looking at trends and trying to understand if you're really pushing the odds too much to one side, to know if you're really taking a long-shot bet or not."

Matt Klentak, Baltimore's director of baseball operations, said recently that the Roberts study was hardly unique. The Orioles used the same process before agreeing with right fielder Nick Markakis on a six-year contract extension worth $66 million and have also delved deeply into any free-agent player they sign.

"We do it in the offseason quite a bit," said Klentak. "We signed a handfull of free agents this year, and any time we start to get down that path, we will assess that player's profile from a number of different perspectives. Again, other than Brian and Nick, we didn't lock anyone up super long-term. I'm not saying we didn't get into that level of detail, but you really don't have to go into quite as much. When you're making a $66 million investment in Nick's case or a $40 million investment in Brian's case, you'd better make sure you did the work."

In Roberts' case, that meant measuring how fast players with plate discipline and doubles power have tended to mature as they push into their mid-30's. Klentak chose not to elaborate on the specifics of his study, but modern-day analysis has shown that aging manifests itself in a number of common trends.

Generally speaking, home runs tend to drop as a player's power begins to wane, and doubles stay neutral because an aging speed player won't be able to leg out as many triples. Simultaneously, walks tend to go up as a veteran player learns how to better exploit a more seasoned knowledge of the strike zone.

Nobody knows whether Roberts will follow those trends, but looking at similar players helps eliminate guesswork.

"Intuitively, we felt pretty good about walk and doubles rates aging fairly well for a player like Brian," said Klentak."I think the conclusion that we reached about his instincts and how that may offset what history might suggest would be a significant regression in stolen bases was something we learned in the study. And we don't know for sure, but we feel a lot more comfortable with Brian's leadoff abilities long-term than we might've a year ago."

Klentak didn't divulge which players his statistical study deemed most similar to Roberts, but he did say the results weren't confined to position. Baseballreference.com uses a similarity index of its own, and its top 10 for Roberts include a 19th century infielder (Fred Dunlap), two catchers and a host of speedy infielders.

That grouping would tend to show a widely divergent path. Rafael Furcal, who's two weeks younger than Roberts, has had a similar career path and recently signed a three-year extension of his own. But a few others -- Mike Lansing, Adam Kennedy and Fernando Vina -- saw their careers drop off in their early 30's.

Roberts, who will turn 32 in October and 36 before he can be a free agent again, said that there's only so much you can learn by looking at the careers of players who had different circumstances.

"Comparisons are good for some things and inaccurate on others. Honestly, I can't tell you what I'll be like at 34, but neither can they," Roberts said. "There are plenty of good players that didn't end up playing much past 29, and there are others where you say, 'Holy cow, he's 39? I never would've guessed.' And the game is totally different, even from the 1980s and early '90s. You can't sit there and say, 'Well, this guy was your size, played the same position and just fell off the map at age 32.' OK, great. He was also probably pretty good at age 24, while I wasn't."

The two-time All-Star took it a step further, explaining that he's not even typical for his type.

"The one thing I talked to my agent about is that everyone says I'm a speed guy, and speed will go down as I age. But I don't really play like a speed guy," Roberts said Sunday. "For one, I've never been a guy that gets out of the batter's box very quickly. I don't get a lot of infield hits, and I'm not reliant on them to hit .300. I don't bunt very much. My numbers, for the most part, are strictly hitting. And as for base-stealing, I stole more bases at 30 than I did at 25. Most of my baserunning is based on understanding how to run the bases and how to steal bases."

To their credit, both MacPhail and Klentak said that the statistical study was just a supplement to what they already know about Roberts, who's well known for having a maniacal conditioning regimen. And in the end, the study was just a tool to underline the things they know and a way to test the things they don't.

"Those are skills Brian possesses that don't necessarily show up on a piece of the paper," said Klentak of Roberts' character. "As Andy leads this franchise back -- with [owner] Peter Angelos' blessings -- it's important for us to really build around quality people. And we hope quality players, but it starts with what's inside first.

"Andy MacPhail has said on the record that our preference was a three-year extension, and that's not driven so much by Brian himself. Because for all the players out there, we feel that it's as good locking up a player of Brian's character, makeup and work ethic as anybody. It just has to do with sheer data. And signing any player to a three-year extension is less risky than signing a player to a four-year extension."