While many of today’s papers are filled with comments on how the signing of Carlos Beltran has brought “credibility” to Flushing (some of us would prefer an 85 win season for starters), the New York Sun’s Tim Marchman takes a closer look at Beltran’s attributes.

Foremost among these is that Beltran has never been a truly great player. His hitting statistics are not those of a superstar, and put in the proper context, they’re less impressive than they seem. For most of his career Beltran played his home games in Kansas City’s Kauffman Stadium at a time when it inflated offense more than any other park in the American League. (In 2002, for instance, it increased run scoring by 17% as compared to an average park.) Despite that, Beltran’s career on-base average is .353, and has never risen above .389. His career slugging average is .490, though he has slugged above .500 the last four years.

Adjusting for league and park effects, and weighting his last three seasons so that each is worth twice as much as the last, Beltran looks to be worth about 30 runs a season more than a league-average hitter. That’s a very good number, but it’s not superstar-level. The same method shows Bobby Abreu, whom few think of as a great hitter, as being worth 49 runs above average per season.

There is, of course, a lot more to baseball than hitting, and much of Beltran’s value is in his well-rounded play. He’s one of the elite base runners in the game, with a career stolen base rate of 89%. That adds significant value – about five runs above average per season, according to the researcher Mitchell Lichtman, who works as a consultant for the St. Louis Cardinals. Defensive systems like Lichtman’s UZR, Clay Davenport’s fielding runs, and Bill James’s win shares see Beltran’s defense as worth about another five runs above the average per season.

Statistics are imperfect, but it would be fairly accurate to say that Beltran is statistically worth about five or six wins above league-average right now. That puts him solidly among the 10 or 15 best players in baseball, in a class below Barry Bonds, Alex Rodriguez, and Albert Pujols, but equal to the likes of Vladimir Guerrero, Miguel Tejada and Manny Ramirez.

What of the intangible factors? While Beltran doesn’t have a reputation as a team leader, neither does he have a reputation as a bad teammate. And for whatever it’s worth, he did have an uncanny postseason last year. That doesn’t make him a clutch god, but surely one would prefer a player who has excelled in October to one who hasn’t, all things being equal.

The important thing for the Mets is what all this means going forward. Beltran was 27 last year, and more players have their best season at that age than any other. It’s likely that starting this year he’ll plateau, or even decline somewhat. On the other hand, Beltran is an exceptionally athletic and well rounded, the sort of player who ages much better than a muscle-bound slugger.