CarGo developments

Carlos Gonzalez’s 2010 breakout season had many believing his star would continue rising. The Rockies were fully on board, giving the outfielder a seven-year, $80.5 million contract extension at the end of 2010. Although his overall numbers for 2011 weren’t as compelling as the previous year, CarGo managed to improve his K/BB ratio, from 3.4 to 2.2 strikeouts per walk.

One caveat to mention is Gonzalez had almost 100 less plate appearances in 2011 than in 2010 (542 PA vs. 636 PA). One could argue he could have leveled to his 2010 levels, but we like to believe that plate discipline does level off well before the 500 PA plateau. Just placing into perspective for those non-believers, Gonzalez would have had to strike out once every three plate appearances and take away eight walks to reach his 2010 figures.

What’s not so easy to determine is in what way has his plate discipline improved. He saw about the same amount of pitches per plate appearance in both seasons (about 3.5 pitches). He’s swinging less in general though, as his swing rate decreased to 48 percent from 2010’s 52 percent mark. His swinging strikes rate has been close to 11 percent in both years too, well above the league average of eight percent.

Carlos’ whiffs

It’s a bit surprising a player could cut down on his strikeouts (and up his walks) but not cut down on his whiffs. I did some analysis on the change in the swinging strikes; where he missed, what type of pitches he missed on, and such. Below are the 2010 and 2011 graphs of the location of Gonzalez’s whiffs.

Just from eyeballing the two graphs, we can see the slight change on the missed balls Carlos committed to. The cluster of points in 2011 look less clustered on the outside part of the plate. Looking at location of the whiffs doesn’t seem to have changed too much though, at least nothing worthy of any statistical change.

Instead, I looked at Gonzalez’s whiffs based on the speed of the pitch. Below is a breakdown of whiffs based off speed, with fastball defined as any pitch greater than 89 mph.

		FA (> 89mph)	Offspeed (< 89mph)	Total pitches
2010 whiffs	32.3%		67.7%			257
2011 whiffs	26.2%		73.8%			221

CarGo has missed on less fastballs in 2011 than in 2010. The shift in whiffs is there, but not at any level we can be confident the shift is real, talent wise (i.e. - I found no significance in a test for independence).

He is swinging less

As noted earlier, CarGo is swinging less in 2011. Below is a summary of swing rates from Fangraphs' BIS data:

			O-Swing %	Z-Swing %	Swing %
2010			37.0%		70.8%		52.2%
2010 Average		29.3%		64.4%		45.6%
2011			35.6%		67.6%		48.9%
2011 Average		30.6%		65.0%		46.2%

His swing rate has declined in both out-of-the-zone and in-the-zone metrics. Compared to the league averages however, Carlos still swings on more occasions.

If we look at the location of pitches taken by CarGo, we see a pattern developing.

The 2d density graphs show where the pitches taken by Gonzalez tend to cluster (the smaller circle shapes can be interpreted as a higher amount of clustered pitches). It is evident that Gonzalez has developed a bit more patience on pitches on the inside part of the plate. A possible reason for this adjustment could be Gonzalez's development for the feel of the called strike zone (i.e. - for lefties, the strike zone is shifted toward the outside part of the plate than the rule book zone).

Conclusions

The primary question mark or flaw in Gonzalez's game was his lack of discipline at the plate. Even though he was still very young, it was the main reason Billy Beane felt comfortable trading him in a package to the Rockies for Matt Holliday. The abysmal plate discipline was just too high of a hurdle for Beane to be comfortable with.

While his plate improvements over the past two years did not take a giant leap like his offensive numbers (almost wining the Triple Crown in 2010), the climb towards the mediocre range of walk and strikeout rates is quite an accomplishment for this free swinger. The Rockies will take any improvements from their big-time investment.

References & Resources
All PITCHf/x data comes from MLBAM via Joe Leftkowitz's tool.

For other articles on Carlos Gonzalez check out Albert Lyu's piece focusing on Gonzalez's Swing% faceted by pitch type and what type of counts he's found himself over the years. Bojan Koprivica also has an article based on the effects of Coors Field on Gonzalez's results.