In Major League Baseball’s past few seasons, there has been an increased emphasis placed on defense. “Saving runs” has become a strategy for teams to manufacture wins during the season. However, have the MLB’s top regular season teams’ adopted the new emphasis on defense? There is a huge spike in the amount of defensive shifts in the MLB since the 2013 season. This change has been driven by the growing analytic departments used by MLB teams. Rather than looking at the simple Defensive Runs Saved (DRS) metric, I use the FanGraphs defensive metric known as DEF(Def = Fielding Runs Above Average + positional adjustment), which measures a team’s total defensive run value adjusted for positions. At a score of 0, the team is considered to be average defensively. Adjusting for position allows for better analysis because defensive plays made by a Shortstop are often harder than a play made by a Left Fielder, and therefore, DEF factors the varying difficulty into their statistic. The total team DEF for each season’s (2003-2017) highest winning team. After looking at the graph, I decided to split the seasons into various intervals to analyze the graph’s trends. The table below shows the DEF Rank, DEF, and Accomplishments of the three highest winning teams per season interval.

Looking further into this, I discovered that the declining average runs per game in the MLB (shown in the table below) could be a factor in the contradiction between the plots. Looking at all the data I collected, I believe that during the 2010-2013 seasons, some of the top MLB teams had not begun to adjust to the declining runs per game rate. If they were winning in the mid-to-late 2000s without strong defenses, Why would they devote focus to defense? However, while some teams were still winning without defense, the rest of the MLB, especially small market franchises, decided to invest in growing analytic departments who discovered that defense could be used manufacture wins without great, usually highly-paid, sluggers. This “moneyball” mentaltility finally came to fruition at the beginning of the 2014 season, as we see the dramatic increase in the defensive shift rate.