A little over two weeks ago, Dave Cameron suggested here that the Astros might need a new first baseman. Last summer, they transitioned newly-signed Cuban prospect Yulieski Gurriel from third to first in hopes he would solve the Astros’ continual first-base issues. Gurriel did not live up to expectations, to say the least. In short, he displayed poor plate discipline as an extremely aggressive hitter, but did not hit the ball with enough authority to overcome his plate approach deficiencies (You can get the more detailed version in Cameron’s article).
However, since the exact day the article was released on April 11, Gurriel has been on a tear. He has accumulated 23 hits in 54 plate appearances, including five doubles and two long balls, to go along with eight runs scored and seven RBI. So, what has Gurriel changed recently?
In his 165 plate appearances in 2016 and up until April 11th, Gurriel posted an absurd 42% O-Swing%. The MLB average is just 29%. He paired that with a 76% Z-Swing%, nine percentage points above average. Gurriel was swinging at anything and everything thrown his way. Since then, he has lowered his O-Swing% to 34% and his Z-Swing% to 68%. Gurriel is showing much improved plate discipline, something he was vaunted for while playing in Cuba. It has not resulted in walks, as Gurriel has drawn only one walk since April 11th, but there is evidence as to why. Let’s look at this rolling average graph of Gurriel’s O-Swing% and Zone% across his career. As Gurriel has continually swung less at pitches out of the strike zone, the number of pitches he is seeing in the strike zone has grown. With more pitches in the zone, he has had less opportunity for walks.
Gurriel has taken advantage of the increase of strikes thrown his way. On his swings at pitches in the zone since April 11th, Gurriel has made contact 97% of the time. The MLB average for Hard% of batted balls from 2016-17 has been roughly 31%. Pre-April 11th, only 27% of Gurriel’s batted balls were hit hard. Post April 11, that number has skyrocketed to 44%. Gurriel is picking his spots now, and when he does decide to swing, he’s making contact. And hard contact.
Previously, pitchers were attacking outside of the zone, knowing Gurriel would swing and produce weak contact. With his decrease in aggression, pitchers have been forced to throw over the plate. Gurriel is sitting on good pitches to hit now, allowing him to make hard contact. The walks have not come yet, but if he continues to play like this, pitchers will learn not to throw in the zone to him. We are dealing with a relatively microscopic sample size here, but players don’t dramatically decrease their aggression just by chance. Gurriel’s current hitting is clearly unsustainable, as he is running a 253 wRC+ since April 11th, but if he continues to show the patience he is playing with right now, don’t expect him to revert back to pre-April 11th Yulieski Gurriel.
So, in summary, what has Gurriel changed?
Not a ton, it appears. He has simply just hit with more patience, which has trickled down into the rest of his game. Gurriel always had the ability to barrel up balls, but he was not showing it because he was not swinging at the right pitches. If Gurriel keeps doing what he’s doing, the Astros definitely won’t need a first baseman.