In three starts for the White Sox, Rienzo has shown a penchant for doing two things—he is emotional on the mound and has trouble finding the strike zone.
There is no mistaking Rienzo's high-energy style. He is in constant motion, employing his own body language in a subconscious effort to help defenders get to balls. He has also shown a penchant for slapping the back of his glove for most outs and the end of the half inning.
His bravado and body language on the mound mirrors that of former White Sox starter Jake Peavy. Unfortunately, that is what is getting him into trouble.
See, the emotion Rienzo displays translates into overthrowing his pitches. Trying to will a cutter past an opposing hitter can quite often lead to a rather troublesome ball/strike ratio.
That is exactly the situation he finds himself in.
According to FanGraphs.com, out of the 295 pitches Rienzo has thrown through his first three starts, 123 of them have been outside the zone. That breaks down to a whopping 42 percent and is why he has issued 11 walks and hit one batter in 18.1 innings pitched.
Right-handed hitters seem to challenge him the most. He issues a base on balls to 20.8 percent and has a .278 BAA against them.
That is a metric Rienzo must improve upon if he hopes to have any real lasting power with the White Sox.
Sure, the sample size is skewed a bit by the fact that he has faced more than twice as many left-handed hitters (58) as right-handed ones (24), but his overall control problems go back to his time in the minor leagues. Between his last two seasons at Double- and Triple-A, for instance, Rienzo issued 91 free passes in 198.0 innings.
To be fair, prior to his last two starts at Triple-A this season when he walked 11 batters in 12.1 innings, he had eight straight starts where he issued three walks or less. When Rienzo is on, he mixes his fastball, cutter and off-speed pitches effectively, which keeps him ahead in the count and opposing batters off-balance.
Failures will happen, and the other team is going to hit home runs or drive balls to the gap that drive in two runs. It is how a pitcher responds that is the true test of character.
Chris Sale is a perfect example. He is at his worst when he responds to giving up a home run by trying to throw the ball through the next batter, but is at his best when he comes back under control and does not try to change anything.
Perhaps the best lesson the young Brazilian can learn is, although emotion and energy are essential for a major league pitcher, they become a detriment, rather than a blessing, when left unchecked.
Rienzo has the talent to be very successful, and with Peavy’s departure, the spot in the rotation is his to lose. While he has shown no fear in his first three starts for the White Sox, it is time to channel that moxie into some strikes.
Rienzo, who has a 2.95 ERA this season, is scheduled to make his next start against the Minnesota Twins on Thursday.