Was Colby Lewis Really That Much Better In The Second Half of 2014?

After missing the majority of the second half of 2012, and all of 2013, due to elbow surgery and hip resurfacing surgery, Colby Lewis returned to the mound in mid-April of last season and due to a plethora of injuries suffered by Ranger pitchers, actually led the team in innings pitched with 170.1. In what was a miserable, insufferable, and intolerable ball of poop featuring the most days lost to the DL since 2002, the pitcher who had missed most of the previous two years actually remained the club’s most healthy.

The predominant thought and narrative surrounding Lewis’ 2014 season was he was horrible in the first half due to just returning from a long absence, and as he became more comfortable as his body readjusted to toeing the rubber every fifth day, Lewis became more productive in the second half.

Many writers will point to Lewis’ dreadful 6.54 ERA in a small sample of 84 innings in the first half of ‘14, and then to his shiny 3.86 ERA in a similarly small sample of 86.1 innings in the second half of ‘14 to validate their argument. Yes, selective end points are indeed fun. However, when parsing the numbers a little, Lewis’ second half resurgence should have been somewhat expected.

Tom Tango popularized a metric, kwERA, which is similar to FIP, but strips home runs out of the equation and instead utilizes only strikeout and walk rate. In a Hardball Times piece from 2012, writer Glenn DuPaul found that when trying to predict a pitcher’s second half performance, strikeout and walk differential, and not ERA, FIP, or XFIP was the better indicator of future performance. As DuPaul points out, since kwERA utilizes strikeout and walk differential, kwERA indeed accomplishes the goal of better predicting second half performance. Despite that horrendous 6.54 ERA in the first half of ‘14, Lewis’ first half K%-BB% was actually 11.8%, which when used to calculate his kwERA, leads one to calculate a first half kwERA of 3.98. As mentioned above, Lewis’ second half ERA was…….3.86. Lewis might have been getting hit hard, but the strikeout and walk numbers were at least palatable. The following chart will now examine Lewis’ batted ball profile from 2010 through 2012, and 2014.


Now, determining whether a pitcher just suffered some bad luck by merely looking at batted balls can be a short-sighted practice as pitchers do have some control over what occurs. However, when one peruses the batted ball numbers, one should be able to determine Lewis did suffer some pretty poor luck in the first half regardless of whether he was adjusting to life back on the mound or not. Colby’s line drive percentage was seven percentage points higher than what he yielded from 2010-12. With line drive percentage fluctuating more so than other batted balls, the number returning to a somewhat similar number to prior levels should not have been surprising. The higher than average line drive rate contributed to the remarkably high for a fly ball pitcher BABIP, which also happened to regress in the second half to normal levels. Lewis had also previously been adept at inducing infield fly balls, which are pretty much equivalent to strike outs regarding guaranteed outs, but Lewis had more trouble generating them in the first half. In the second half of 14’, the number returned close to what it had been from 10-12.

So, I guess that should conclude my piece. Lewis was not as awful in the first half as his ERA suggests, and his second half resurgence should be accredited to regression. Well, not exactly. As the author mentioned above, the pitcher still has to hold himself accountable for some of his poor performance. Let’s take a look at some of what Lewis did to improve his chances for regression in the second half. The charts were obtained for the magnificent Brooks Baseball.



The graphs represent Colby Lewis’ pitch usage in the first and second half respectively. The majority of the differences are negligible, but there is one conspicuous difference. Lewis tried to use a sinker against left-handed hitters quite often in the first half, but greatly decreased the sinker’s usage after the All-Star break due to lefties slugging .565 against it in the first half. In the second half, lefties put the ball in play more often, but Lewis managed to avoid as much harm as lefties only slugged .407 despite the pitch actually being put in play more often. Colby also made some mechanical alterations as the season wore on.

When Colby returned to the mound, his vertical release point was the lowest it had been since he rejoined the Rangers. This could be due to a variety of factors, but as Colby became more comfortable, his release point began to return to where it was when he was successful. Perhaps the lower release point was intended to try and make the sinker more effective, but as Colby reduced the sinker’s usage, his vertical release point increased, which can make spotting his high fastball a little simpler.

One can see Colby’s horizontal release drastically change by the month as well. The farther negative the release point, the farther toward the third base side of the mound Colby was. As the season wore on, Colby began to inch over towards the first base side of the rubber. As one should determine, Colby’s release at the end of the season was completely different than it was at the beginning of the season. Perhaps Lewis had difficulty determining what was comfortable early in the season. Next we will look at the location of Colby’s pitches from the first and second half.


The reader should notice Lewis’ second half included darker shades of red both in the actual strike zone, and higher in the areas which are typically used to induce fly balls and pop outs, which have been Lewis’ specialty since his return from Japan in 2010. Colby’s strike out percentage dropped two percentage points after the All-Star break, while his walk percentage also dropped slightly. The final chart is something which the author touched on earlier, but did not contain vivid lines the reader hopefully finds enthralling.

Again, Lewis tried a sinker early in the season, which was when his ERA was sky high, but decreased the usage to the point where he actually used his change-up more frequently in August. As the season progressed, Lewis appears to have adopted the strategy of throwing his fast ball for strikes more often. It is really that simple. Commanding the fast ball is incredibly important as it usually allows the pitcher’s secondary stuff to be more effective. However, Colby’s whiff rates did decrease slightly in the second half for what it is worth.

A few interesting items of note is while the narrative is Colby pitched much better in the second half due to his lower ERA, one could argue Colby actually pitched better in the first half despite the bloated ERA over 6.00. Lewis allowed five more long balls in the second half, and his FIP and xFIP were both lower in the first half while he was being shelled. There have been numerous articles in the past explaining why ERA is not very reliable in determining overall pitcher performance, and one believes Lewis’ first half is pretty indicative of this. While the author will cede Colby was mechanically and strategically more effective in the second half, the fact his ERA was three full runs worse before the break does not necessarily support the fact his first half was far worse.

Ranger fans have been enamored with Colby Lewis since he returned to the team in 2010 as he was superb for them in the playoffs in both ’10 and ’11, and his presence on the mound reminds us of the most successful period in franchise history. His resilience and willingness to stay in Texas are both admirable, and make rooting for the guy fairly easy. However, relying on Lewis this year due to his ’14 second half might be fairly difficult. Steamer projects Lewis to yield a 4.67 ERA and 4.86 FIP, while PECOTA portends a 4.27 ERA for the right-hander. Reminder, the AL average ERA and FIP in ‘14 was 3.92 and 3.85, respectively.

So, while one understands the “veteran presence” and ”this guy is a good fourth starter” clichés spewed since Lewis re-signed last December, one must also be weary of giving too many innings to a replacement level starter. Yes, eating innings is valuable, but if the innings being pitched produce below average results, that is the opposite of valuable. There is also Lewis being the third most likely pitcher to suffer an injury according to Jeff Zimmerman’s injury predictor model. While one year deals are rarely considered short-sighted or poor investments, and the odds of Lewis generating surplus value are not exactly astronomical, relying on Lewis to be one of the better pitchers in the rotation in 2015 might not be wise.

The thought that Lewis is ready to return to prior levels of performance based on his second half are rather silly because other than some mechanical improvements, he really did not improve much statistically in the second half of ’14, and much of that improvement could be attributed to regression. And if one would be satisfied with a 4.00 ERA  in ’15 from Lewis because he is your fourth starter, and you think the fourth starter has to be a Lewis type or something similar, remember a 4.00 ERA is not really that good anymore in this pitching dominated era.

The author’s intention was not to poopoo on Colby Lewis (although it may seem that way) as one is quite fond of him, and appreciative of the wonderful baseball memories he has provided, but this is 2015, and relying on a 35 year old Lewis might not be a shrewd strategy for a team that fancies itself as a contender. While Lewis is currently listed as the Rangers fourth starter, he might not be the fourth best starter currently in the organization. Yes, Lewis did make some changes after the break last season, but regression also helped lower his ERA, and he was not pitching as poorly as the ERA for a guy who was not even throwing between starts suggested it did.

Dustin Dietz
Dustin graduated from the University of North Texas with a degree in Radio/TV/Film, and a minor in history. He will often write about pitching mechanics and analytical baseball stuff. You will more than likely disagree with the majority of what he writes or says. In his spare time, Dustin time travels and plays at a replacement level in slow pitch softball leagues.

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