Major League Baseball has experienced a sea change of sorts over the past year and a half with the baseball and launch angle adjustments serving as the under current. The service level changes which are best demonstrated in home run frequency have forced teams to make various adjustments and shifted player value based on specific skills. Ben Lindbergh and Mitchell Lichtman’s outstanding research provided the basis for the understanding that the ball used in Major League games had been altered in some sense.
The testing revealed significant differences in balls used after the 2015 All-Star break in each of the components that could affect the flight of the ball, in the directions we would have expected based on the massive hike in home run rate. While none of these attributes in isolation could explain the increase in home runs that we saw in the summer of 2015, in combination, they can.
Still, there are further changes, an increasing strikeout rate in Major League Baseball in part based on shifting pitch mix strategy as well as continuing increases in velocity. With this in mind, two key categories increased the most over the past three years, home runs and strikeouts. With increases in categories such as these, that impacts the entire run scoring environment as well as the strategies which should be deployed in order to produce optimal run scoring. Further, certain offensive skills are improved in the altered paradigm which can be most easily demonstrated through Fangraphs seasonal constants.
First on wOBA, it is created based on the notion that not all hits are created equal in terms of run production. Indeed, home runs , triples, and singles all have different impacts on run expectancy. Seasonal constants serve the role of weights which change yearly based on frequency. This plays the role of smoothing based on the run-scoring environment. Now for the information above, there are a couple important trend lines. First, due to the spiking home run rate, the seasonal home run constant has decreased three consecutive seasons.
Second, and most important for this analysis, the negative value of a runner caught stealing has increased dramatically over the past three season to heights similar to that of the steroid era. This is important for a couple of reasons but the declining value of attempting a stolen base can easily be explained with logic as well as verified by the above chart.
First, apply the increase in home runs, which are blind to where runners are positioned on the bases in terms of scoring calculation. Increased frequency of home runs decreases the marginal value gains of moving from first to second or second to third. Second, increasing or spiking strikeout rates diminishes the value of a runner advancing from station to station because when overall contact frequency diminishes base runner station is irrelevant.
The Indians went from 134 steals in 2016, to 88 steals in 2017. From 185 home runs in 2016, to 212 home runs in 2017. When the frequency of not only home runs but also extra base hits in general increases, the risk-reward calculus of stealing a base or taking an extra base changes.
This was partially based on roster construction and partially based on the context of baseball in 2018, unless a team can convert stolen bases at an inordinately high rate, the attempt merely serves to endanger a teams run expectancy. The Indians were not only less aggressive in stealing bases they were far less aggressive in taking the extra base. In 2016, the Indians took the extra base 45 percent of the time. Whereas, in 2017, the Indians took the extra base 38 percent of the time.
The Indians did not lack for athleticism with Francisco Lindor, Jose Ramirez, Yandy Diaz, Bradley Zimmer, and even Carlos Santana being effective base runners but the Indians were simply far less aggressive on the bases, likely, in large part due to the radically change run scoring environment.
Unless the frequency of home runs decreases significantly, the strikeout rate decreases, or base stealing impossibly carried a much higher success rate, the payoff for the risk of being caught simply pressures teams to be far more conservative on the base paths. While small ball and a speed driven offense is a quaint topic often, and where some may wish to assert the existence of baseball nuance, the juiced ball and launch angle revolution have radically decreased their relevance. In 2018, with a lot of power in the middle and a deep lineup, do not expect the Indians to risk too many outs with aggressive base running.