Laying Down the Bricks: Inside Jimmy Nelson’s Development | Disciples of Uecker

Disciples of Uecker

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Here at DoU, one of the main cogs that makes the machine grind ahead is the implementation of analytics and statistics. Though it may not currently provide the mood, the state in which the Brewers are currently situated offers arguably the best time to use those measures of intellect. It presents itself and becomes tangible through many different facets, but one angle takes a higher road than all of the rest: hope. One of the many examples of this is the aspiration that a young player can have a breakthrough year when everything else seems to go wrong. For the Brewers, one of the players at the forefront of that category is Jimmy Nelson. Though on paper it may not seem as if he had an impressive year with an 11-13 record with an ERA over 4.00, Nelson affirmed the one quality that fans hope to see in a player of his stature: development. Through a series of visual descriptions, I will be showing you how Nelson made advancements that may have gone unnoticed and laid down the bricks of a road that could lead to a place with progressive potential. All of the visualizations were created through ESPN’s TruMedia dataset.

Heavy breathing may occur throughout the reading of this article.

Exhibit 1: Nelson’s Overall Increase in Effectiveness

Though his frequency resonated in a near identical manner from 2014 to 2015, Nelson’s success in the zone concerning the wOBA stat (weighted on-base average) went under a formidable amount of positive changes in the span of a year. Take a look at the differences below:



Two main improvements are spawned by Nelson in the heat maps above. First, he flipped the tables and experienced much higher success in the upper left part of the zone. The lower section of the plate also became friendlier ground for the right-hander, lowering the wOBA mark to below .375. In fact, his already low .157 SLG/P in that third of the zone dropped to .131 in 2015, garnering success at a higher rate.

Exhibit 2A: Nelson’s Sinker vs Right-Handed Batters

As the heat maps below illustrate, Nelson shifted a majority of his sinkers against right-handers to the inside part of the dish:



By featuring his sinker consistently on the hands of right-handed hitters, Nelson constructed a lower wOBA in that part of the plate:



Notice how more blue fills the innermost part of the zone compared to that same area in 2014. It begins to look like the Pacific Ocean. Also, even though he did not accentuate his sinker low and away as much in 2015 as the previous season, Nelson still maintained a decent on-base average in that section of the plate. A large chunk of red vanished in 2015 near the top of the plate as well. Heading into the 2015 season, that high-third part of the zone was a problem that seemed it could cause worries with a wOBA treading toward .500 but Nelson was able to keep it in check around the .375 mid-range mark. Overall against hitters from both parts of the plate, Nelson lowered the BA on his sinker from .338 to .310, as well as in these other categories:

Season Pitch K % BB/K AVG OBP SLG OPS
2014 SI 8.0 % 0.93 .338 .403 .446 .849
2015 SI 10.2 % 0.79 .310 .375 .428 .802

Exhibit 2B: Nelson’s Slider vs Right-Handed Batters

As the story to his sinker goes, so goes the story of his slider. In like fashion, it progressed against batters from the right side in 2015:



Obviously, the preeminent change from the heat maps present the elimination of an unhealthy habit: sliders being planted at the top of the zone. The worst place for a breaking pitch to sit is high and even with the eyes, as problems are just bound to become plentiful when pitchers travel down that road. Thankfully for Nelson, he concentrated a majority of his sliders where they are meant to be thrown: down low and away. This may be due to just a more focused approach or by tweaking his arm slot angle a few degrees in the process of the delivery. One slight problem regarding accuracy with his slider still exists in the central part of the zone, as it can tend to stick there on occasion. With another year of development under his belt, hopefully Nelson can evade from parking sliders there as frequently as he did in 2015.

The next pair of graphics analyze the change Nelson’s slider underwent in regards to wOBA:



Nelson extinguished exceptional results in developing his craft in the top part of the zone, though as we discussed previously, that is not the optimal placement for a breaking pitch. However, Nelson continued to pose a wOBA well below .375 near the low outside corner of the plate. In fact, he operated a rise in O-Swing % of 37.3 percent from batters in 2014 to 42.0 percent in 2015. Now, what exactly does that mean? In the span of a year, Nelson increased the rate at which right-handed batters swung at pitches out of the strike zone by five percent. In turn, that signifies the sharp movement he imposed on opposing hitters with his slider. This is evident from viewing the xMov (horizontal movement) increase of 4.4 from 2014. If Nelson continues to maintain solid breakthroughs with this pitch, he will become more feared in late-count situations and his slider will transpire into a very complimenting put-out pitch.

Exhibit C: Ability to Eliminate Damage w/ RISP

Perhaps one of the most alluring growths that Nelson accomplished from 2014 to 2015 was his ability to weather the storm with RISP. Young pitchers like Nelson can easily become rattled and flustered when the odds begin to stack against them. However, in 2015, Nelson was acquainted with high tension situations more frequently than he was the prior year. For the most part, he showed composure and a refusal to crumble, taking major strides forward. Take a glance at these stats below:

Season High Leverage IP H ER HR BB SO AVG OBP SLG wOBA
2014 High Leverage 4.1 9 9 1 1 1 .474 .545 .778 .554
2015 High Leverage 11.2 9 13 1 4 10 .220 .311 .333 .279

Let’s dive further into the advanced sets of this data:

Season High Leverage K/9 K % WHIP FIP xFIP
2014 High Leverage 2.08 4.6 % 2.31 7.75 5.32
2015 High Leverage 7.71 21.7 % 1.11 3.82 3.59

The progress continues to shine bright. Nelson exhibited upward traction in a bulk of sabermetric categories when mounted in pressure situations. His heat maps also paint a similar picture:



That enormous red belt at the mid-top of the zone evaporated to near full extent in the span of just a year. Nelson also rid the lower part of the plate of a small cluster of SLG over the .550 mark to manageable rates. In fact, take a peek at just how well he subdued offensive numbers across the board when presented with RISP:

Season Men In Scoring AVG OBP SLG wOBA
2014 Men In Scoring .299 .358 .482 .367
2015 Men In Scoring .229 .340 .312 .287

The renovation of scenarios with RISP can also be displayed through the heat map comparison of ISO with RISP from 2014 to 2015:

More elimination of red. Nelson’s overall ISO with RISP dropped, along with his SLG in the same scenario, which went from .482 to .312 in 2015. For his age, he has depicted a tenacious sense of not becoming bewildered in pressure situations, an area which one can cross their fingers that he becomes even more dominant in as he continues to mature.

Exhibit D: Implementation of a Curveball 

One of the main downfall’s to Nelson’s approach was being too one-dimensional with his pitches, thus creating the need for an off-speed pitch to compliment his slider. Enter the curveball. 2015 saw him introduce a deuce that he threw 486 times, many of which were adequate. Here are his stats on the pitch (which FanGraphs refers to as a knucklecurve) below:

2015 KC .257 .329 .311 .640 .054

Overall, not too shabby for the first year of throwing a new breaking pitch. Here are some advanced stats that detail the movement:

Season Pitch xMov zMov Mov O-Swing % O-Contact % SwStr %
2015 KC 4.7 -6.5 8.2 23.3 % 46.3 % 9.1 %

All in all, some pretty decent action partnered with some average SwStr percentage (swings and misses / Total pitches). Here are some heat maps detailing the work Nelson carved out with it:

Considering it was his first full season utilizing a real curveball, it is difficult to be too dissatisfied with the frequency of his placement. However, adjustments should begin to be made this upcoming season in regards of the ball becoming too familiar with the central part of the plate. Pitchers who hang curveballs are playing with fire and the potential for major damage being inflicted.

As was frequently mentioned, Nelson held hitters to a .257 batting average on his curveball. The heat map above shows where hitters tended to find strengths and weaknesses. Out of all the pitches in his arsenal, his curveball ranks as the third lowest batting average, trailing only his slider (.192) and fastball (.292).

With another year on the horizon, Nelson should continue zeroing in on further skills and linger along on the journey of mastering his curveball.

Addressing Major Concerns

Now, I hope it does not seem as if I am perceiving Nelson to win the Cy Young. That kind of breakout and potential is not what I am attempting to postulate in this article. There are plenty of kinks that need to be hammered out before he can even be relied on as a No. 1 starter in the rotation. Right now, the major calamity that is staring him straight in the eyes is his struggle with left-handed hitters. Compare the two tables below:

Season Batter Hand AVG OBP SLG wOBA
2014 R .307 .364 .417 .349
2015 R .198 .275 .293 .255

His change in stats among right-handers are quite remarkable. However, the same cannot be said in regards to his time with left-handers:

Season Batter Hand AVG OBP SLG wOBA
2014 L .271 .340 .465 .353
2015 L .298 .381 .495 .376

Perhaps it is something that has been jumping around the Brewers clubhouse in recent years, as Nelson’s teammate Wily Peralta has significant trouble with lefties as well. Unlike all the other heat maps we have provided you in this piece, a pretty sight is not presented when comparing his stats to left-handed hitters:

The outside of the plate is where lefties simply feast on Nelson’s pitching, as the SLG charts describe above. The following heat maps of ISO and wOBA back up the evidence of lefties making at least 83 percent contact on the far third of the strike zone against Nelson:

Not as big of an increase as SLG, but still enough to be worried about. Last but not least, here’s how lefties fare in wOBA against Nelson:

Yikes. The tradition continues. Once again, much more perches itself on the outside part of the strike zone. In regards to his development, Nelson’s approach to lefties (mainly the outer third part of the plate) will be the weakness he must endeavor to alter. If he can preserve the success gained in 2015 with righties and just eliminate even a slight amount of troubles against lefties, Nelson could be poised for a breakout year.

As was mentioned at the beginning of this article, there will be many fun parts about this season, despite the common theme of it being represented as a nightmare straight out of hell. However, we may be watching something special develop in Nelson. He has the potential. He has the tools. It is just all a matter of whether or not he can put the pieces together correctly.

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