Decrease in Run Production Might Be Due to Defense

This is just a short little post today, but I think it raises a decent question in light of comments made my Mark Cuban about how there is no evidence that shows human growth hormone improves athletic performance.  In fact, evidence shows that it has no significant effect on performance and there is also some information developing that shows that therapies using this hormone are unlikely to produce tissue that is functional for an athlete.  In other words, hGH therapies are probably ideal for individuals who simply need to heal as opposed to those who need to heal for athletic competition as well as not for those who used it to reduce down time between cycling of other chemicals.  This really is not much of a surprise because gym rats and athletes have rarely been on the cutting edge for any therapeutical chemical use.  Conventional wisdom tends to think that everything that successful players do must work because the players are successful.  We should recognize this as being absurd.  However, we tend to believe, as a population, in fantastically simple explanations, such as magic pills and treatments devised by non-science majors who have no practical skills beyond taste testing performance supplements.

With this in mind, shouldn't we also consider the possibility that something that has been shown to increase muscle mass and improvement in some forms of athletic events, such as anabolic steroids, might also not have been all that impacting?  A few years back, I noted how we have all of a sudden been treated to an amazing improvement in fastball velocity since around 2007.  Additionally, there also appears to be a relationship between velocity and run environments.  I think that makes sense and should be readily acceptable.

Another consideration I wish to make is this: run environment and appreciation of defensive ability are also linked.

Consider the graph below showing numbers from the American League over the past decade and a half:



How does that relationship work with the run environment?



It actually fits pretty well, which is an impressive thing because errors are a very limited measurement of defensive ability.  In fact, errors are a pretty poor way to measure defensive ability as evidenced by our infamous Rubbermaid Trashcan notion.  That is, such a trashcan would have a 1.000 fielding percentage while also being the worst defender in baseball.

Anyway, I think that it is plausible to think that along with increased pitcher velocity that a greater appreciation (or measurement) of defense probably also contributed to the decline in the run environment.  This more and more marginalizes the conventional wisdom of drug testing impacting the game in a very significant way.  As teams began to realize the importance of preventing runs then they began to move away from the pure mashers who produced runs at a significant cost to defense.  At least, that would be the narrative explanation to carry forth this hypothesis.