The Maturation of Taijuan Walker


I will be the first to raise my hand and admit that I was all aboard the Taijuan Walker bandwagon prior to the 2015 season. I may have led the coalition, as I predicted Walker was going to win AL Rookie of the Year and the Seattle Mariners were going to the World Series (along with the Nationals – whoops). My reasoning was that Robinson Cano, Nelson Cruz, and Kyle Seager were going to be the newest three-man wrecking crew and that Felix Hernandez (my Cy Young prediction) and Walker would be the nastiest 1-2 combo in the game. As we all know today, I was dead wrong.

But hey, 2016 is a new season. And maybe I was just a tad early with my optimism surrounding the Mariners and Walker. The Mariners are atop of the AL West by a game and a half. You can nearly write off the A’s and Angels already, and the Astros better hope Lance McCullers can save their season. All of the teams in the West have their own flaws, but I think the M’s might have the fewest. A major reason for their success is their pitching, which current ranks #1 in ERA in the American League (3.11). Walker currently boasts a 2.63 ERA, 3.08 FIP, and a 9.08 K/BB. The right-hander was a consensus top-10 prospect in baseball prior to the 2013 and 2014 seasons and in his limited exposure to the Majors those two years, he seemed like a guy ready to burst onto the scene in 2015.

Yet throughout the majority of the 2015 campaign, Walker struggled to find any consistency. He put together a few brilliant starts, giving us a sense of how good he could be, but could not string those quality starts together. He finished last season with a 4.56 ERA, 4.07 FIP, and 3.93 K/BB.

So the question is – what is the kid from Louisiana doing differently from last season to this season? We must remember, he is only in his second full season in the Majors, so his sample size is relatively small. But there is one factor in particular he has certainly improved on.

Let’s start with his fastball. The guy throws hard and he knows it. He sits at roughly 95 MPH and can top out around 98 MPH. All I know is, if I could ever throw that hard, I would throw that pitch every time. Who wouldn’t? So in his first full season in the Majors, Walker figured he could gas everyone up. He threw his fastball roughly 65% of the time, depending on which source you are getting your information from. However, that 65% does not mean much if it isn’t put into context. Let’s take a look at his pitch usage in 2015 provided by Brooks Baseball:

T Walker Pitch Usage 2015

I went ahead and highlighted what will help explain the bigger picture in just a moment. Against lefties, Walker threw his fastball 53% of the time when ahead in the count and 58% of the time with two strikes. Those numbers are even higher when facing righties. On the other hand, he is only featuring his curveball 14% of the time against lefties when working ahead and 8% of the time with two strikes – basically identical for right-handers as well. Now let’s look at this season:

T Walker Pitch Usage 2016

In comparison of these two graphs, we can see some major differences from 2015 to 2016. After featuring his fastball over 55% of the time when either ahead in the count or with two strikes in 2015, that percentage has dived all the way down into the 40% range. That is an extremely dramatic shift in his game. And what I had highlighted is his curveball – which he has thrown 19% of the time while ahead in the count this season and 11% with two strikes against lefties. You will also see a spike in his splitter and cutter usage as well. The incorporation of off-speed pitches has allowed for Walker to induce softer contact and more ground balls.

Taijuan Walker Soft Medium Hard


While Walker may have been roughed up in the 6th inning yesterday, he was absolutely dominate through the first five innings. He had K’ed up eight to that point and did not issue a walk or a run. He ran into trouble in the 6th however, when he issued three walks and eventually dished up a hanger to Dickerson, who delivered a “Papa Slam” for all of us pizza lovers. I know this is easy to say, but if you were to wipe away that 6th inning from Walker, we are looking at yet another dominant start from the 23 year old right-hander. Us fans currently witnessing a flamethrower turn into a pitcher; a step that many young pitchers need to take early in their careers. While an upper-90s fastball may be flashy, it will not work consistently against professional hitters for long.


Speaking of secondary pitches, check out this GIF provided by Pitcher List of Walker’s devastating splitter running in on Danny Valencia earlier this season. For a right-handed pitcher to be able to run a pitch in like that on a right-handed hitter is just plain wicked. No one can touch that.

Lastly, I ran across something extremely strange and it is something completely out of Walker’s control – the strike zone. I am not necessarily talking about the numbers of balls and strikes the kid can throw, but the percentage at which they are called strikes, particularly on the outside half of the plate to right-handed batters. Let me provide a visual for you:

Taijuan Walker Called Strike 2015

Taijuan Walker Called Strike 2016

What you are seeing here is completely baffling to me. In 2015, Walker was totally pinched on the outside corner of the plate when facing righties. Like, less than 50% of pitches INSIDE THE STRIKE ZONE where called a ball. Beyond absurd. Over the years, pitchers seem to be squeezed more and more on the inside half of the plate, but not the outside corner to this extreme. And it wasn’t like this guy was some wild flamethrower who couldn’t hit the strike zone. He was someone who had a modest 2.12 BB/9 ratio, and a catcher in Mike Zunino who was one of the best pitch-framers in the game last season. My only explanation would be where Walker has been locating his pitches this season. He has been working the outside edge considerably more than last season. And as you see in the heatmaps above, he has been getting less calls on the inside corner.  What does this all mean? He has been throwing more pitches away from right-handers and they are now called strikes more often than not. On top of that, he has been missing less over the middle of the plate than he did last season. Is that a result of pounding the outer half more often than the insider corner? Possibly.

In short, Taijuan Walker has taken the correct steps forward in becoming a solidified starter in the Majors. While he still has some way to go, it is a good sign to see him committing himself to pitches other than his heater. If he continues to trust and work on his secondary pitches and can keep hitters on their toes, we may see one of the more dominant pitchers in the league for the next decade.

About the author: Jack Conness

Graduate of UW-Milwaukee. Baseball nerd. Follow him on Twitter! @JackConness