Examining Chris Archer's pitch arsenal

Chris Archer was drafted in the 5th round of the 2006 MLB Draft by the Cleveland Indians. After spending three seasons in the Indians' organization, he was traded to the Cubs with two other prospects in 2009 for Mark DeRosa. Two seasons later, he was shipped to the Rays in the Matt Garza trade. While the other prospects the Rays received haven't panned out, Chris Archer has developed into a strong rotation piece for the Rays.

However, the outlook on Archer hasn't always been positive. During his time in the minors, his fastball and slider received good reviews, but there were questions about the rest of his pitch arsenal. His lack of a third pitch led some to question whether he could make it as a starter, or if he would be forced to become a closer at some point. Furthermore, scouts were concerned with his command, as he posted walk rates upwards of 4.00 BB/9 in extended stays in the upper minors.

Since his arrival in the Major Leagues, Archer has proved his doubters wrong. In his first full season in 2013, he posted a 3.22 ERA and 7.06 K/9, good for a third place finish in the American League Rookie of the Year voting. He improved on that in 2014, increasing his strikeout rate to 8.00 K/9, and accruing 3.1 WAR.

Let's take an in-depth look at how Archer has achieved this success by analyzing his individual pitches.

Fastball

Since his first Major League appearance in 2012, Archer has been averaging between 94 and 96 mph on his fastball, which is well above the league average of 92 mph. Studies have shown that fastball velocity is significant in getting whiffs and preventing home runs, so Archer's above average fastball velocity has definitely contributed to his success in the majors.

Archer utilizes both a two-seam and a four-seam fastball. Both pitches have gotten decent whiffs (whiffs per swing), but his two-seam fastball has excelled at generating groundballs. According to MLBAM pitch classifications on FanGraphs, he generated groundballs on 56.8% and 49.3 % of the balls in play on his two-seam fastball in 2013 and 2014, respectively. Groundballs have a BABIP around .235, and pitchers who throw more ground balls are less likely to be victimized by extra base hits.

In 2014, Archer's four-seam fastball had a batting average against (BAA) of .351, which was a 128 point increase from 2013 and caused it to be less effective as a whole. This increase was most likely driven by a .395 BABIP. Studies have shown that a pitcher doesn't have control over his BABIP, suggesting that his BAA will regress in 2015.

Slider

In addition to an above-average fastball, Archer features an excellent slider, which he often uses to get batters to chase pitches outside of the strike zone. Being a right-handed pitcher, Archer's slider moves away from right-handed hitters, and towards left-handed hitters. According to Fangraphs, Archer threw his slider outside of the strike zone 42.5% of the time last year. Batters made contact on the sliders that were outside of the strike zone only 42.8% of the time. This was much lower than their contact rate on his other pitches, which averaged around 70%.

Because this pitch is so effective at getting batters to swing and miss, Archer tends to rely on it as his strikeout pitch. In 2014, when he had two strikes on a batter, Archer threw his slider 47% of the time against right-handed hitters, and 35% of the time against left-handed hitters.

His usage patterns are perfectly demonstrated by these heat maps from BrooksBaseball.net.

The heat map above shows that he throws the slider low in the strike zone and away from right-handed hitters. This second heat map shows that he has been successful in getting batters to swing and miss by doing so.

Against left-handed hitters, the roots of his success with his slider are a little more difficult to pin down. Because the pitch moves in on a left-handed hitter, he can't cause them to chase the same way he does with right-handed hitters. In this heat map, we see that Archer throws his slider on the outside part of the plate, or low and inside to left handed hitters.

Archer generated most of his whiffs against left handed hitters on the sliders that were low and inside. However, he did not get as many whiffs on pitches that were on the outside part of the plate.

This led me to believe that these pitches were starting outside, and then breaking in toward the batter and catching the outside of the plate, resulting in a called strike. To see if this was true, I looked at outcomes from sliders against lefties on pitches on the outside and middle parts of the plate.

This image, generated from Baseballsavant.com, shows that a large percentage of these pitches resulted in called strikes. On a pitch that normally has significant right/left handed splits, Archer has utilized his slider to get both righties and lefties out, which has been key to his success.

When batters did make contact on his slider, they didn't do very much with it. In 2013, Archer allowed only one extra-base hit on his slider to right-handed hitters for the entire season. For his career, he has used it to hold batters to a paltry .189 BAA. While this BAA isn't as low as pitchers who have truly elite sliders, like Yu Darvish, who held batters to a .137 BAA on his slider last year, Archer's slider still grades out as one the best in baseball.

Changeup

While Archer's first two pitches are elite, his changeup serves as a mediocre third option. He threw his changeup only 4.5% of the time last year, and he threw it almost exclusively to left-handed hitters. On the surface, his changeup looks average, posting a 44% groundball rate and an 11.2% swinging strike rate, but I believe that this was because it was "protected" and not used enough for it to be truly exposed.

Additionally, some of the counts in which he tended to use his changeup are possible causes for concern. Archer used it more when he was behind in the count in 2013 -- he threw it 14% of the time when he was behind, and only 7% when he was ahead. This is most likely because his changeup generated swings and misses below the below-average rate of 14.9%. While he used his changeup when he was ahead more often in 2014, he still threw it very rarely when he had two strikes on the batter.

Because of this, Archer's two-strike pitch was often his slider. While his slider has shown to be effective, hitters may be able to catch on to his tendencies. Pitchers that can use their changeup to generate swings and misses have the luxury to be able to throw this pitch as another option to strike a hitter out, and keep batters off balance.

His changeup moves in the opposite direction of his slider -- toward right-handed hitters, and away from left-handed hitters. To lefties, his usage pattern is similar to that of his slider against right-handed hitters. Because the pitch breaks the opposite way, it we would expect it to create a similar swing and miss effect that is created with his slider against right-handed hitters. However, the expected results from this aren't seen in his heat map.

We are dealing with a small sample of pitches in this specific case, so there is a chance that he may generate more whiffs if he throws more changeups. However, it appears that his changeup was unsuccessful in causing batters to chase in 2014.

Overall, Archer will need to continue to improve this pitch to maintain his major league success.

So What Does This All Mean?

Archer should continue being a solid pitcher for the Rays in 2015 and for the foreseeable future. He should experience "negative" regression in some areas in 2015, as his HR/FB rate will probably rise back up to league average, and his strand rate should creep closer to league average as well. Even with these minor changes, we can still expect Archer to post close to 3.0 WAR and have the potential for more.

One of the biggest positive aspects of Archer is his contract. He signed an extension in April of 2014, with only 158 innings of major league pitching under his belt, at six years for $25.5 million. He will only make $1 million this year, and his current performance would be commanding much more money in free agency. Archer will be a key piece to this rotation for the next few years, and will continue to emerge as one of the game's best young pitchers in 2015.

Data used in this article is from FanGraphs, BrooksBaseball.net, and Baseballsavant.com.