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The Rise of Rasmus

During the disappointing 2010 season, one of the bright spots for the St. Louis Cardinals was the breakout performance of the much-ballyhooed centerfielder of the future, Colby Rasmus. Largely thanks to his offensive emergence, Rasmus moved to the head of the MLB centerfield class, even being considered this week as one of three finalists for centerfielder of the next decade by Rob Neyer.* Given the skill Rasmus has displayed with the glove and the bat throughout his professional career and fresh off a productive 2010 season, being considered for this forward-looking distinction is fitting for the budding star.

*There is a poll which allows for members of the VEB community to vote for Colby Rasmus as the likely centerfielder of the twenty-teens, if you are so inclined.

Rasmus's rookie season of 2009 was somewhat disappointing. The disappointment began when, in April of 2009, the Cardinals had no t-jerseys* for sale at Busch Stadium for those of us in the hyperventilating prospect geek contingent** and continued throughout the duration of the season. While Rasmus clearly showed himself to be a superior defender, he floundered in mediocrity at the plate. Rasmus put up a line of .251/.307/.407/.714, which produced a .311 wOBA. A batter known for his eye at the plate managed only a 6.9% walk rate to accompany a 20% strikeout rate. Nonetheless, his glovework helped make his debut season a solid value for the Cardinals to the tune of 2.8 Baseball-Reference WAR (1.7 dWAR and 1.1 oWAR). 

*Despite him knowing far more about the English language than I do, I am challenging the label used by DanUp for the red player t-shirt faux jerseys sold by the Cardinals. I have always used the "t-jersey" label to describe the t-shirt jerseys clubs sell. DanUp uses "shersey." I leave it to the VEB community to decide which made-up word will be the first from VEB to make it into a dictionary.

**I tried explaining to the nice lady at the team store that a Rasmus t-jersey was a better value than a Pujols t-jersey because Pujols was only signed through 2011 while Rasmus would be under team control long beyond that, meaning we would get more wears out of a Rasmus t-jersey than a Pujols one, but she had no idea about which I spoke. I suspect that, after the last week, she now knows.

In 2010, Rasmus exploded onto the scene with an Edmondsian April.* Rasmus hit .323/.463/.708/1.171 with 6 homers, which equates to a .480 wOBA. After this dynamic April, Rasmus had a streaky season at the plate that was in many ways reminiscent of the Edmonds of MV3 vintage. There were spans of such white-hot production that it seemed a new MV3 was blossoming, but these spurts were offset by slumps where Rasmus looked utterly lost at the bat. Using the arbitrary frame of month-to-month production, Rasmus's 2010 season is one of dramatic peaks and valleys with three months of wOBA in the .280s and three months of wOBA of .380 or higher. Another blemish on Rasmus's breakout is the increase in his K rate from 20% in 2009 to 31.9% in 2010. Even so, Rasmus wound up with an excellent overall line for the 2010 season, posting a .366 wOBA which reflects his .276/.361/.498/.859 line and 23 home runs. The .366 wOBA Rasmus posted was in the top 15 for all MLB outfielders and was third-best by a MLB centerfielder behind AL MVP Josh Hamilton and NL MVP contender Carlos Gonzalez. For the season, according to Baseball-Reference, Rasmus put up 2.9 WAR (3.8 oWAR and -0.9 dWAR).

*In April 2000, his debut month wearing The Birds on the Bat, Jim Edmonds hit .382/.515/.776/1.291 with 8 home runs. After, 2000, great Aprils for centerfielders are "Edmondsian" since it is not at all fair to compare anyone's April production to the Pujolsian April of 2006:  .346/.509/.914/1.423 and 14 home runs.

How is it that Rasmus improved his OPS by 145 points and his wOBA by 55 points? Using batted ball information and the wonderful Pitch F/X charts available at, we can get some idea.


Compared to 2009, Rasmus seemed to have a higher comfort level at the bat in 2010. As noted above, Rasmus only managed a walk rate of 6.9% during his rookie campaign. This was significantly lower than his career minor-league walk rate of 12.24% and the drop was concerning. In 2010, however, this concern was washed away as Rasmus was back to his patient self in the batter's box, drawing a walk in 11.8% of his plate appearances. Counterintuitively, Rasmus swung at more pitches outside the strike zone in 2010 (28.6%) than in 2009 (25.6%) and swung at fewer pitches in the strike zone in 2010 (71.4%) than in 2009 (73.4%). This is likely due to the fact that Rasmus saw a lesser share of strikes in 2010 than he did in 2009, with the percentage of pitches thrown to him in the zone falling from 50.9% to 42.6%. So, Rasmus saw fewer strikes, consequently swung at a few more balls, but still managed to nearly double his walk rate. 


A large share of the success experienced by Rasmus in 2010 was due to significant improvement when swinging at the first pitch. It is important to note that Rasmus swung at the first pitch far less in 2010 (68 PAs) than in 2009 (86 PAs). This increased selectivity likely contributed to improved results due to Rasmus swinging at pitches he could drive. In 2009, Rasmus hit .313 when swinging at the first pitch. Four of his 16 total home runs came on the initial offering from the opposing pitcher, as did six of his 22 doubles. It is not surprising then that, while Rasmus only slugged .407 for the season, he slugged .554 on the first pitch he saw. Last season, Rasmus feasted on the first pitch when he swung at it. He hit first pitches for a .477 average and slugged them to a .985 percentage. Eight of the 23 homers he launched and 7 of his 28 doubles were roped on first pitches. Rasmus went from an sOPS+* of 90 on the first pitch as a rookie to an sOPS+ of 223 as a sophomore. Another leap was found in Rasmus's HR/PA when swinging at the first pitch, which increased nearly threefold from 4.65% in 2009 to 11.76% in 2010.

*Remember that sOPS+ measures a hitter's performance against the league-average in that situation. An sOPS+ of 100 is league-average. The further above 100 a player's sOPS+, the better the player's performance. The further below 100 a player's sOPS+, the worse the player's performance. An sOPS+ of 90 is not very good. An sOPS+ of 223 is Pujolsianly ridiculous.

The spray charts available at the indispensable provide an excellent visual of the increased success Rasmus experienced on the first pitch. Green squares represent a hit; red squares, outs. Note the increase in green hits scattered about the green grass of the outfield in 2010 as compared to 2009. Also, take heed of the green hits deposited beyond the outfield wall.






Another key to Rasmus's improved offensive production largely appears to have been the way he handled the fastball. In 2009, fastballs were an effective pitch against the rookie Rasmus; in 2010, the sophomore Rasmus annihilated them. Placing the Fangraphs "Pitch Value"* shoe on the other foot, Rasmus went from suffering a -4.5 runs against the fastball in his premiere year to 18.5 runs against the pitch type in 2010, a turnaround in hitting fastballs as dramatic as Jason Motte's turnaround in throwing them. During his debut season, pitchers fed Rasmus a large share of fastballs on the first pitch, likely due to the problems he had in handling the big-league breed of a heater. According to the fantastic Pitch F/X database, 44.6% of the first pitches Rasmus saw were fastballs, and 61.7% of those were in the strike zone. In 2010, the percentage of fastballs Rasmus saw on the first pitch fell to 36.5% with 57.4% being placed within the zone.

*You can read a brief introductory post on Fangraphs about the Pitch Value tool at this link.

Again, the spray charts available at offer a nice visualization by which one can see the improvement Rasmus experienced against the fastball as a second-year player. You will notice that Rasmus made more outs against the pitch in 2009 and that those outs take place more often to the left side of the field and up the middle than in 2010.






It seems safe to say that Rasmus has done well to adjust his approach when ahead in the count, looking for a pitch within a certain zone when the pitcher falls behind against him, and then driving it. During his rookie campaign, Rasmus managed only a .243/.402/.346/.748 line when getting ahead in the count. This is well below the league-average as evidenced by Rasmus's sOPS+ when ahead in the count, which was an abysmal 50.* The OBP is acceptable, but the average and power numbers are disappointing given the advantage as a batter he possessed in such situations. In Rasmus's sophomore season, he leveraged getting ahead in the count much better. When Rasmus got ahead in the count, he put up an excellent slash line of .290/.518/.496/1.014. Rasmus posted a sOPS+ of 109 when batting ahead in the count in 2010, a 59-point improvement over his rookie year which is reflective of a line which is a tick above league-average.

*Remember that sOPS+ measures a hitter's performance against the league-average in that situation. An sOPS+ of 100 is league-average. The further above 100 a player's sOPS+, the better the player's performance. The further below 100 a player's sOPS+, the worse the player's performance. An sOPS+ of 50 is horrible. An sOPS+ of 109 is pretty decent.


Lastly, Rasmus also dramatically improved his results when pulling the baseball. While he experienced success when pulling the ball in 2009 to the tune of a .467 wOBA--hitting .386 and slugging .715--the centerfielder soared to stratospheric heights in 2010. As has been noted on VEB in the comments section, in 2010, when Rasmus pulled the baseball, he annihilated it. Rasmus put up a .608 wOBA when pulling the ball, which was good for third-highest in all of MLB behind the Green-Monster-assisted Kevin Youklis and recently minted Ten-Millionaire Jose BautistaRasmus hit .460 when pulling the ball and slugged a ridiculous .917, as well.*

*How much of his .382 BABIP when pulling the ball in 2010 is luck could be the determining factor in Rasmus's ability to improve in 2011 on his 2010 success. Rasmus's batted ball profile for pulls looks like this: 22.9 LD%, 49.3 GB%, and 27.9 FB%. Also keep in mind that BABIP does not include homers while wOBA most certainly does.


After breaking down this data, we stand on firm ground in deducing that the strides made by Rasmus in 2010 are concrete ones that reflect a matured plate approach. Rasmus became more selective, offering at pitches early in the count that he is capable of driving with power--and drive with power he did. Rasmus has also evolved into a hitter that is more than capable of handling a big-league fastball. When watching Rasmus early this season we ought to get a good indicator of whether his 2010 is repeatable if not improvable by paying attention to how Rasmus handles the fastball, how often Rasmus strikes out, and how Rasmus performs when ahead in the count.