There are certain statistics that get tallied on scorecards such as hits, walks, runs, and strikeouts. These aren’t the modern, comprehensive measures of performance we typically use here at FanGraphs, but they are the building blocks of those metrics. Without singles/doubles/triples/etc, there is no way to build wOBA or wRC+. Without strikeouts, walks, home runs, and innings pitched, there is no FIP.
While we’ve generally moved beyond caring about certain counting stats, we use them to build the things about which we care a great deal. But there is at least one standard scorecard event that doesn’t get a lot of attention when we build these metrics because it’s extremely rare and also extremely subjective: the balk.
The layman’s description of a balk is easy enough to understand: it’s a movement made by the pitcher intended to deceive the runner into thinking that same pitcher is about to throw towards home, when in reality he (the pitcher) is not. Any reasonably informed fan knows that the specifics of the balk rule are complicated and enforced at the whims of the umpire. It’s a judgment call, and one that doesn’t seem to be uniformly implemented at any given moment in time. But there are trends in balking:
This graph deserves two explanations. First, let’s discuss 1988. The balk rule was changed in 1988 and if you didn’t know the results of the change, the actual difference in the wording of the rule might not catch your eye. I’ll allow Theron Schultz of Recondite Baseball to explain:
Baseball Official Rule 8.01(b): The pitcher, following his stretch, must (a) hold the ball in both hands in front of his body and (b) come to a complete stop.
1988 Baseball Official Rule 8.01(b): The pitcher, following his stretch, must (a) hold the ball in both hands in front of his body, and (b) come to a single complete and discernible stop, with both feet on the ground.
The difference between the two rules is that the 1988 version replaced “complete stop” with “single complete and discernible stop, with both feet on the ground.” This slight change, intended to make balk calls more uniform throughout major league baseball, instead sparked one of most frustrating summers ever for major league hurlers. Only six weeks after opening day, Rick Mahler of the Atlanta Braves committed the 357th balk of the 1988 season, breaking the MLB record for most balks in a complete season… with three-quarters of the season to play. Before all was said and done, American League pitchers were called for a staggering 558 balks. Their National League brethren had it a little easier, “only” committing 366 balks.
This is a wonderful bit of trivia, but it obscures the broader trend: fewer balks are being called across the league. We have data back to 1974, and since that time, there has been a clear decline in the number of balks called in major-league baseball (shown in the graph as balks per 162 games). Here’s the same graph a before, now with a truncated y-axis for easier viewing:
It’s unclear if umpires are letting pitchers get away with more balking behavior or if pitchers are less guilty than they used to be, but the trend is rather clear. There was also a rule revision before 2013 outlawing the fake-to-third-throw-to-first move, which shaved about a balk per team season from the league.
Read the rest of this entry »