Did Playing for the St. Louis Cardinals Leave Carlos Beltran a Changed Batter?

After the St. Louis Cardinals won the 2013 National League pennant, we took a look at the different plate approaches between the Redbirds and the Boston Red Sox. The inspiration for that post was Doug Mittler's piece in ESPN the Magazine," which looked at how some clubs were experiencing batting success by being more aggressive at the bat. One of those clubs with a free-swinging batting philosophy was St. Louis.

In 2013, MLB batsmen on average saw 3.83 pitchers per plate appearance (P/PA). El Birdos' "selectively aggressive" plate approach resulted in them, as a team, seeing 3.75 P/PA. That ranked 27th in all of baseball. To put it another way, the Cards as a team saw the fourth-fewest P/PA in the majors.

While the aggression in the Cardinals' selectively aggressive plate approach is reflected in their low P/PA rate, the selectivity is shown in their walk rate (BB%). The Cardinals posted a 7.8% walk rate in 2013. NL batters walked in 7.7% of their PAs in 2013. The Redbirds' 7.8 BB% ranked 14th in MLB, just a touch above average.

For Mittler's article, he asked Cardinals manager Mike Matheny about the club's batting philosophy:

"We don't try to make any guy a robot and be exactly what we think they should be," St. Louis manager Mike Matheny says.

I completely believe Matheny when he says that the Cardinals coaching staff does not try to take every player and mold him into a selectively aggressive batter. Nonetheless, if the coaching staff is preaching such a plate approach, a player might, of his own free will, decide to adopt it. This appears to be the case with veteran outfielder Carlos Beltran.

When Beltran initially broke into the big leagues, he was a free-swinger. As Beltran aged, his plate approach changed. Perhaps pitchers became more weary of challenging him early in the zone as he showed more power at the bat. Perhaps Beltran's selectivity increased because his batting eye became more skilled with experience. Most likely, it was a little bit of both. Whatever resulted in the change, Beltran started swinging less often and working deeper into counts.

In 2002, Beltran's walk rate climbed to 9.8%. Beginning in 2003, Beltran posted a walk rate of 10% or higher in eight out of nine seasons prior to joining the Cardinals. He also consistently posted above average walk P/PA rates over the same time period.

Beltran evolved into a player who drew walks and hit for power. This made him a nice replacement of sorts for departing first baseman Albert Pujols, who also worked walks and slugged. When the Cardinals signed Beltran after the 2011 season, his stat line looked like this:

In 2012, Beltran became a more aggressive hitter while maintaining a double-digit walk rate. Last year, Beltran's P/PA fell yet again and his BB% plummeted. Beltran's batting profile in 2013 was very different than what it was throughout much of his career.

Beltran still hit for impressive power in the pitcher-friendly confines of Busch Stadium, but he did so while swinging more often than he did throughout much of his pre-Cardinals career. Perhaps the most dramatic example of Beltran's free-swinging as a Cardinal is the fact that he posted an OBP in 2013 that was seven points lower than it was in 2012 even though Beltran's BA last year was 27 points higher. Beltran's aggression at the bat was a startling transformation.

The New York Yankees are apparently not very concerned about Beltran's change in plate approach as a Cardinal. Over the weekend, it was reported that the Yanks signed the 36-year-old outfielder to a three-year contract for $45 million. In Beltran's return to the Big Apple, it will be interesting to see if his time in St. Louis has permanently left him a different, more aggressive batter.