It was a filthy pitch. Somehow, that gets lost in the narrative. Carlos Beltran could not have known, as he watched Adam Wainwright’s unhittable curveball drop from shoulder-height in its final milliseconds to split the plate at his knees, that it would become the defining moment of his seven-year career with the New York Mets.

But it did. In Game 7 of the 2006 NLCS, with the St. Louis Cardinals clinging to a 3-1 lead in the bottom of the ninth, with the bases loaded and two outs, Beltran had just watched strike three. Never mind that curveballs from lesser pitchers have been buckling the knees of better hitters for 150 years. Never mind that Wainwright, a rookie who had spent the year in middle relief — he had only three saves that season before the Cardinals, out of desperation, made him their playoff closer — went on to become one of the best starting pitchers in baseball over the next four years.

And never mind that the Mets would never have been an extra-base hit away from the World Series without Beltran carrying them there. In New York, where success and failure are magnified and where truth sometimes succumbs to hype, Beltran’s legacy was cinched. Five years later, the New York Times summed up his tenure thusly: “Even if he had taken one last lusty ‘Casey at the Bat’ swing, and missed, perhaps his fate would have been different. But he gawked.”

The crucible of baseball’s postseason dispenses reputation with cold finality. Bill Buckner was a pariah in New England for two decades for letting a ground ball squirt through his legs. Pittsburgh Pirates fans still have not forgiven Barry Bonds for a weak throw to home plate that allowed Sid Bream to score the series-winning run in the 1992 NLCS. These plays didn’t single-handedly cost their teams victory, but they were obvious and memorable mistakes. Beltran, on the other hand, did what dozens of major league hitters do every day: He refused to go fishing for a curveball with two strikes. It just so happened that this particular curveball had teeth.

The San Francisco Giants are defending World Champions, and they are well-poised to defend their title in the playoffs. Even after dropping their last two games to the Arizona Diamondbacks, they are tied with Arizona for the NL West lead. The Giants are not nearly as good as their 61-49 record would suggest — they’ve actually been outscored by their opponents by five runs this season. For the second straight year, the Giants have a world-class pitching staff — second only to the Phillies’ universe-class staff in runs allowed — covering for a mediocre offense. Actually, this season’s offense aspires only to mediocrity. The loss of catcher and 2010 Rookie of the Year Buster Posey in a brutal home-plate collision has hit hard. After finishing ninth in the National League in runs scored last season, the Giants are tied for last this year.

Brian Sabean has been general manager of the Giants since 1997, and one common thread marks his tenure: He likes old guys. Whether it was sticking with underpowered first baseman J.T. Snow for most of his 30s or signing Aaron Rowand to a five-year, $60 million contract after Rowand’s one All-Star season, Sabean prefers players with some gray in their beards. Sometimes he trades for 34-year-old Ellis Burks and is rewarded with a pair of excellent seasons. Other times he gives Barry Zito a seven-year contract for $126 million, a decision he will probably never live down. Because — or despite — Sabean’s predilection for older players, the Giants have five playoff appearances and 10 winning seasons in his 14-year tenure.

In 2010, every veteran gamble Sabean took paid off. He signed 33-year-old Aubrey Huff before the season, after Huff had hit .189 as a late-season addition to the Tigers’ lineup the previous year. With San Francisco, Huff rebounded to hit .290/.385/.506 and finished seventh in the MVP vote. Andres Torres, who was a 31-year-old minor league outfielder when the Giants called him up in 2009, hit 43 doubles, eight triples, and 16 homers, stole 26 bases, and played excellent defense in all three outfield positions. Still desperate for offense, Sabean signed 33-year-old Pat Burrell after Tampa Bay released him. After hitting .218 with 16 homers in a little more than a season with the Rays, Burrell rebounded to hit .266 with 18 homers for the Giants. And in August, when the Florida Marlins put 29-year-old Cody Ross on waivers, Sabean claimed him. Ross hit well for the Giants down the stretch, then bashed five homers and batted .294/.390/.686 in the postseason.

The Giants wouldn’t have won the 2010 World Series without their castaway veterans. But old guys have a troubling tendency to play like old guys, and the rent came due this year. Burrell was released last week. Burrell was hitting .233 before he went on the DL last month. Huff is hitting .240/.294/.368 this year, and rookie Brandon Belt has threatened to take his job away. Torres is hitting .233 with three homers. Cody Ross is still Cody Ross.

Brian Sabean is still Brian Sabean; when old hitters stop hitting, his solution is to bring in more old hitters. But this year, with Posey on the shelf and without a credible shortstop on the roster, the Giants’ offensive problems were too serious to paper over with guys picked up off the waiver wire. They needed a star.

Carlos Beltran made the game look easy. That was his gift, and that was his curse. He was the Royals’ Opening Day center fielder in 1999, having never played a game in Triple-A, and by the end of the season he had batted .293, hit 22 homers, stolen 27 bases, scored 112 runs and driven in 108, and won Rookie of the Year honors. After missing half of the 2000 season with an injury, he was a fantastic player the following three years, toiling anonymously in baseball’s hinterlands.

In 2003, the Royals led the AL Central for four months with a patchwork rotation (the team’s Opening Day starter was Runelvys Hernandez), a no-name bullpen, and a lineup filled with average hitters. And Beltran. That year he batted .307, hit 26 homers, stole 41 bases, and got some MVP consideration.

As good as Beltran was, many thought he could have been even better. He played excellent defense, but his specialty wasn’t banging into fences in pursuit of Web Gems; he had the audacity to pull up rather than risk injury. He had the speed to steal 60 or 70 bases, but instead he picked his spots, stole 35 or 40, and almost never got caught. (For his career, Beltran has been successful on 88.2 percent of his stolen-base attempts — the highest success rate in baseball history for a player with at least 120 steals.)

Discretion may be the better part of valor, but it’s not the best way to earn a reputation. Beltran needed to do something spectacular to shake the perception that he wasn’t getting the most out of his talent. In 2004, he did. Finally freed from the Royals and traded to Houston in June, Beltran hit 23 homers in 90 games, stole 28 bases in 28 attempts, and helped the Astros eke out the wild card by a single game over the Giants.

Then came the playoffs. Beltran homered in Game 1 of the NLDS, and again in Game 3, and the Astros won both games. The Atlanta Braves won Games 2 and 4, setting up a winner-take-all Game 5. Beltran homered twice, and the Astros won, 12-3.

Facing the Cardinals in the NLCS, Beltran homered in Game 1. And again in Game 2. And again in Game 3. Then, with the Astros down two games to one in Game 4, Beltran homered in the seventh inning to break a 5-5 tie. The Astros won 6-5 to knot the series at two. It was one of the most impressive playoff performances of all time — and it’s nearly forgotten today, as the Astros-Cardinals series was overshadowed by the epic Red Sox comeback from a 3-0 deficit against the Yankees.

The Astros took Game 5, and the Cardinals were one out away from winning Game 6 when Beltran batted with the tying run on second. The Cardinals chose to intentionally walk him — to face Jeff Bagwell. Bagwell singled to tie the game, but the Cardinals won in 12 innings, then won the NL pennant the next night. In 12 playoff games, Beltran had hit .435, had homered eight times, and had stolen six bases. But he went home empty-handed.

That winter, Beltran signed a seven-year deal with the Mets. After a disappointing first season in Queens, Beltran hit a career-high 41 homers in 2006, and the Mets had the best record in the National League. Beltran was a quiet 2-for-9 in the first round of the playoffs, a three-game sweep of the Dodgers. Then, in the NLCS, his bat came alive. In Game 1, Beltran hit a two-run homer in the sixth inning, and the Mets won, 2-0.

After the Cardinals took Games 2 and 3, Beltran paced the Mets with two home runs in Game 4; they won 12-5 to tie the series. The teams traded Games 5 and 6, and then came Game 7. Beltran doubled in the first inning and scored the Mets’ only run, on a David Wright single. In the bottom of the eighth, with the score tied at one, Beltran led off with a walk, but the inning ended with him stranded at first.

But still, the thing almost everyone remembers is Beltran’s strikeout to end the NLCS.

Beltran hasn’t had a chance to build on his playoff résumé since. In 2007 the Mets had a seven-game lead on the Phillies with three weeks left in the season, and in 2008 they had a 2.5-game lead for the wild card with just nine games remaining. They blew both leads, which only cemented the perception of Beltran as a player who folded under pressure. Never mind that in 2007 Beltran hit .282/.328/.555 in September, or that in 2008 he hit .344/.440/.645 in the season’s final month.

Here’s the final tally: In 22 playoff games, Beltran has hit .366 with 11 homers. He has stolen eight bases in eight attempts. His OBP is .485, sixth all-time among players with at least 40 postseason at-bats. His slugging average of .817 is the highest in playoff history — by 60 points! His playoff OPS (on-base plus slugging) of 1.302 is also the highest ever. (Babe Ruth and Lou Gehrig, appropriately enough, rank no. 3 and no. 4.)

Beltran’s called strike three shouldn’t define him any more than Katy Perry’s Christian rock album defines her.

The Giants needed a hitter, and Beltran, in the final year of his contract, needed a home. It was an obvious match.

The price was steep. Beltran is 34 years old and he can still hit. He batted .289/.391/.513 with the Mets and leads the NL with 30 doubles. But his knees are shot, and he’s no longer capable of playing center field. His speed is almost gone; he has stolen only three bases so far this year. Due to a provision in the contract he signed with the Mets, San Francisco cannot offer Beltran arbitration at the end of his contract — meaning they won’t be awarded any draft picks if he signs with another team this winter.

Despite that, the Giants wanted Beltran badly enough that they sent one of baseball’s best pitching prospects, right-hander Zack Wheeler, to the Mets. That’s because Brian Sabean really likes his veterans, and the defending champions really needed a hitter. At least this time Sabean had the opportunity to acquire one who was worthy of his regard.

After seven mostly unhappy years in New York, it remains to be seen whether there’s another act to Beltran’s career. He’s still an elite player when healthy, and this year he made his sixth All-Star team. He will soon become just the eighth player in major league history with 300 career homers and 300 career stolen bases. If he’s able to stay healthy and productive into his late 30s, he’s going to have a better Hall of Fame case than almost anyone realizes.

In the meantime, the Giants are giving Beltran a chance to rewrite his legacy. The shame is that he shouldn’t have to.

Rany Jazayerli runs the Rany on the Royals website and co-hosts The Baseball Show with Rany and Joe podcast. He is one of the original founders of Baseball Prospectus, and works as a dermatologist in suburban Chicago.

Previously from Rany Jazayerli:

The Cleveland Indians’ wheeling and dealing

The Pittsburgh Pirates’ playoff chances

The Milwaukee Brewers’ big bats defy baseball’s conventional wisdom

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