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Could the Oakland A’s Move Brett Anderson to the ‘Pen?

MLB: Houston Astros at Oakland Athletics
Would a move to the Oakland A’s bullpen increase Brett Anderson’s effectiveness?
Kelley L Cox-USA TODAY Sports

I had relatively high hopes for Brett Anderson this season when news broke of his return to Oakland. The talents has almost always been there, but the durability has not. After a handful of games started and a stint on the DL I think it’s clear that both skill and health have eluded Anderson this season.

Over the weekend the case was made for a new approach that might lead to a transformation similar to that of Rich Hill. I don’t fully see the potential there for that much of a leap. However, I do think Anderson can make the transformation from mediocre starter to quality relief pitcher.

This idea certainly isn’t unique to me, as many others have expressed this option previously. I was skeptical at first due to Anderson’s generally “meh” performance this season, but I’ve come around lately. In the post referenced above I left a few brief thoughts in the comments section and I wanted to expand upon them in a longer piece.

The recipe for quality MLB reliever does vary, but generally includes some combination of three key ingredients:

  1. One above-average pitch
  2. Velocity
  3. Effective vs. same-handed batters

Let’s take a look at what Brett has going for him in these three areas.

It Begins with the Slider

Anderson’s best pitch has always been his slider, both aesthetically and statistically. For his career it has graded out as his only above-average pitch at 46.2 runs above average. That ranks 17th best among all starters with at least 700 IP since 2009 (Finally something an A’s pitcher is better at than Justin Verlander!). His 13.3 career swinging-strike rate on sliders is by far the best mark of any of his pitches.

Statcast agrees that his slider is a quality pitch both in actual results and expected results.

Anderson’s Slider per Statcast

Year Pitch Type BA xBA SLG xSLG wOBA xwOBA Whiff%
Year Pitch Type BA xBA SLG xSLG wOBA xwOBA Whiff%
2018 Slider 0.226 0.212 0.258 0.262 0.277 0.276 27.1
2017 Slider 0.250 0.246 0.319 0.346 0.258 0.273 26.7
2016 Slider 0.571 0.335 1.000 0.533 0.668 0.416 16.7
2015 Slider 0.226 0.181 0.319 0.284 0.245 0.211 24.9
2014 Slider 0.235 0.353 0.269 31.4
2013 Slider 0.200 0.271 0.238 34.1
2012 Slider 0.255 0.327 0.268 27.3
2011 Slider 0.220 0.295 0.241 21.4
2010 Slider 0.172 0.212 0.208 31.0
2009 Slider 0.193 0.269 0.210 28.9

SO far in 2018 his .276 xwOBA against is 60th best among MLB starting pitchers and his actual wOBA of .277 is 64th best. There isn’t really a doubt that it is a quality pitch. Since Statcast began tracking data in 2015 Anderson sits at 21st and 42nd in MLB xwOBA and wOBA, respectively. There is no doubting that his slider is his best pitch, and a very good one in general.

Can He Dial it Up?

Anderson’s fastball velocity has decreased each season since his big-league career began. Not a good starting point. However, that isn’t uncommon! And often starting pitchers who move to the bullpen see a bump in their fastball velocity.

Fortunately we have some data from which we can draw a conclusion.

In 2013 Anderson appeared in 10 games as a reliever in which he threw 3 innings or fewer. His average fastball velocity was 92.7, however in the games in which he pitch less than 3 innings his fastball ranged from 93-94 and average 93.6 in his final 6 appearances. Could Anderson reach upper-90s heat with his fastball? I doubt it. However, I believe he could add a few ticks of velocity simply by maximizing his effort for shorter stints.

Is He a Lefty Specialist?

With Ryan Buchter being Oakland’s 3rd best reliever, arguably, and having the ability to pitch to lefties and righties the need exists for an additional left-handed reliever. Anderson may just be that guy. Although this is the quality of which I am the least sure.

More traditional numbers suggest that Anderson hasn’t fared much differently versus left-handed batters than righties.

Anderson’s Career Splits

Handedness K% BB% K-BB% HR/9 WHIP BABIP FIP xFIP
Handedness K% BB% K-BB% HR/9 WHIP BABIP FIP xFIP
vs L 15.5 % 5.3 % 10.2 % 0.59 1.49 0.357 3.43 3.41
vs R 17.7 % 7.0 % 10.8 % 0.92 1.32 0.302 3.88 3.72

His BABIP versus lefties is inflated, which is a reason for optimism given that his HR/9 is much lower. Statcast also provides reason to believe he may be effective if only deployed against lefties.

Anderson’s Statcast Splits (‘15-’18)

Handedness wOBA xwOBA xBA Exit Velocity Launch Angle
Handedness wOBA xwOBA xBA Exit Velocity Launch Angle
vs. L 0.349 0.292 0.245 83.8 -2.9
vs. R 0.345 0.336 0.278 86.6 4.4

His quality of contact allowed is far preferable against lefties and suggests that same-handed batters could struggle against Anderson, especially when he’s only asked to get a maximum of 3 or 4 outs at a time.


Anderson definitely checks one of the three boxes necessary of a quality reliever. The evidence does, however, lead me to believe that he could fulfill at least one of the other two requirements needed and should the A’s decide to pursue rotation help he could step into the bullpen and be an asset.

Much like lefties Brad Hand and Zach Britton, who each went from middling starter to relief ace, Anderson could make adjustments to his repertoire and usage in order to increase his effectiveness.

In order to work Anderson would have to be up for it and the A’s would have to believe in the potential outcome. I think it’s something the team should explore - do you?


Should the A’s Transition Anderson to the Bullpen?

This poll is closed

  • 61%
    Yes - He should improve there.
    (264 votes)
  • 12%
    No - He’s needed as a starter.
    (56 votes)
  • 23%
    I’d rather not see him as either.
    (100 votes)
  • 2%
    Other (explain in comments section)
    (11 votes)
431 votes total Vote Now