Colorado Rockies pitchers have had a stubbornly consistent walk rate and a declining strikeout rate

Over the last couple of weeks, Bryan Kilpatrick has written about the trouble Rockies hitters have at the plate, especially on the road. He found that, among the other frequently identified problems, the Rockies’ aggressiveness at the plate and related infrequency of taking walks is also a reason for offensive woes on the road. It’s an absent skill magnified by a lack of hits.

As a follow-up, I thought it would be instructive to look at the walk rate from the pitchers side. One of the frustrating things about the lack of walks on offense is that it keeps traffic off of the bases when the ball is put in play. Similarly, watching Rockies pitchers offer the opposition free traffic can be just as frustrating. Using the same chronological set as Bryan, 2007-2014, this is what I found for the Rockies pitchers and their walk rate:

Season	BB%	League rank
2014	8.5	29
2013	8.3	21
2012	8.9	27
2011	8.4	18
2010	8.6	14
2009	8.6	11
2008	8.9	18
2007	8	10

The team has remained remarkably consistent with regard to bases on balls over the past eight seasons. But the rest of the league has changed. As a consequence, the Rockies’ ranking relative to the other 29 teams has fluctuated from tenth best in baseball in 2007 to second worst in 2014. The two teams to make the postseason and the 2010 squad that fell apart in September show the best walk rates relative to the rest of the league. That the Rockies’ pitching staff has kept a walk rate between 8.0 and 8.9 percent for every season for the past eight years might be worth investigating. But I found something else while pursuing this trend.

If the Rockies have remained consistent with regard to walk rate, how well have they done in terms of strikeouts? League wide, strikeouts are becoming more and more (and more) prevalent. But Rockies pitching isn't following this trend.

From 2007 to 2010, the Rockies strikeout percentage increased year to year, peaking at about 20 percent in 2010. Aside from 2008, those were also good teams. From 2011 to 2014, however, Rockies pitchers have struck out a lower percentage of batters faced. Those were, in general, not very good teams. All the while, most other pitching staffs were striking a higher percentage of batters out. Over the past three seasons, the Rockies have sat near the bottom of baseball in strikeout percentage. The fact that the Rockies have not been party to the strikeout trend is magnified because of what the rest of the league is doing. The closest comparison to the Rockies over this time period is the Minnesota Twins.

Season	K%	League rank
2014	17.2	29
2103	17	28
2012	17.9	28
2011	18	19
2010	20.1	6
2009	18.7	10
2008	16.4	22
2007	15.4	27

Below, you’ll find a very big table. This is what’s in it: every team season from 2007 to 2014, totaling 240 seasons. The table is sorted by strikeout percentage and is color-coded by season. In addition to strikeout percentage, you’ll also find walk percentage, strikeout-to-walk percentage, and team ERA- (how much better or worse the staff was relative to league average, which is 100; lower is better). Notice how the 2012 to 2014 seasons dominate the top of the chart. As you scroll down, you’ll see less and less yellow, red, and blue, as the chromatic selection of those years becomes sparse. At the same time, you’ll notice the colors for the 2007-2011 seasons popping up with greater frequency. What’s interesting is that the same pattern exists when sorted for walk rate. Because you’re most interested in the Rockies, you’ll find them bolded.

Data courtesy of FanGraphs

The question of where the Rockies rank in terms of a league-wide trend drive the search for the bold in this visual representation. The search yields two potential answers and one conclusion. The possible answers are, first, that the Rockies have either been left behind by the trend of increasing strikeouts, or, second, they have stood behind to watch the trend take its course. The conclusion is that it’s a little bit of both.

It’s not an accident that teams with a high strikeout percentage also tend to have a high strikeout to walk percentage. Those teams tend to also be strong in ERA-, which captures how well the staff was relative to the rest of baseball. Those all add up to quality pitching, which is a necessary component of overall quality. In other words: they’re good. The Rockies since 2011 have not been good. Additionally, over the past few seasons, the Rockies have openly adhered to a pitch to contact philosophy. A low strikeout percentage is a natural consequence of that.

The Rockies are one of only a handful of teams who, from 2007 through 2014, have not exhibited a notable and steady increase in strikeout percentage. All the while, they’ve remained internally stable with regard to walk rate, even though their ranking relative to the rest of baseball has been unstable.

There is a potential way the Rockies’ existence outside of the thick of these walk and strikeout trends might turn beneficial. One of the reasons that strikeouts have gone up is that the strike zone has expanded; it’s also an explanation as to why the Rockies' walk rate remains stable but has gotten relatively worse. Increased strikeouts have led to declining offense, and declining offense, in the eyes of new MLB Commissioner Rob Manfred, is a problem. There is already indication that the strike zone might shrink in 2016.

If the strike zone gets smaller, and if Rockies pitchers can maintain their respectable but not great walk rate between eight and nine percent, they can improve in that area simply by virtue of many other teams getting worse. In the past few years, the Rockies have gotten worse by virtue of other teams getting better. If the smaller strike zone makes pitching more of a contact game in an attempt to increase offense, the Rockies are already playing that game, and they just might be at an advantage for it. But these are symptoms of trends as they relate to the Rockies—any diagnosis drawn about what it might mean is purely speculative.

When looking at the evidence above, I keep coming back to the same thing: Rockies pitchers were best at limiting walks and striking batters out in 2009 and 2010. Those were two of the three best pitching seasons in Rockies’ history, 2007 being the third, by ERA-. They were also the two highest pitching fWAR seasons in Rockies history; they included Ubaldo Jimenez’s two five-win seasons. Walk rate and strikeout rate, especially relative to everyone else, are two important components of a good pitching staff. To be more successful on the field, Rockies pitchers should allow fewer walks and strike more batters out. Doing both at the same time would also be super.

That, however, is just another way of saying they should just be better baseball players. Every organization wants all of their players to be better. But improvement is never isolated. What really matters is improvement relative to everyone else. In this way, environmental changes can be leveraged to work in a team's favor. It's not something any team should stake the future in, but it is something.