On the Consequences of the New Balk Rule

On an individual-player basis, I think we can all agree that spring-training statistics suck. If you’re a reader of FanGraphs, or if you’ve even just heard of FanGraphs, you probably understand that these numbers aren’t predictive. Oh, we’ll always allow ourselves to trick ourselves. Giants fans will allow themselves to believe in Brandon Belt, and Mariners fans will allow themselves to believe in Justin Smoak. We can always trick ourselves to believe in the positive while dismissing the negative. But, guns to our heads, we’d all say “Ahh! Put that gun down!” And then we’d acknowledge that, truthfully, even the positive numbers probably don’t mean much.

But now consider spring-training statistics as a group, as a whole. What is spring training but a whole bunch of baseball games between high-level professionals? What are the numbers but reflections of what took place on the field during ordinary baseball games? Just because the numbers probably won’t tell you much about what will happen doesn’t mean they don’t tell you what has happened. That is precisely what they do. And for our purposes here, we can make use of overall, league-wide spring-training statistics.

There’s a new rule in place, that has to do with balks and pick-off attempts. You probably know what I’m talking about, but just in case it slipped your mind:

Under a rule change imposed by Major League Baseball, pitchers will no longer be allowed to fake a pickoff to third base and throw to first as a way to dupe a runner on first base into breaking for second. Next season, that move would be a balk.

This is a move that people have long thought was a balk anyway, at least based on fan reaction when it was attempted by pitchers. That move never failed to generate a ton of eye-rolls, even though every so often it did succeed in picking off a runner, so the rule change was widely met with not-anger. Few are the changes these days that people don’t get angry about. People are easily angered by change.

But not everyone was a fan of the rule change. Specifically, some pitchers are going to miss having that little move in their back pocket. We can hear from one Jon Garland:

“I’ve actually gotten a couple guys with it,” he said. “It doesn’t have to work to work, necessarily. It might keep that guy at first one step closer. Maybe on a base hit, he doesn’t hit to third. There’s little things like that that get overlooked. That’s kind of a part of controlling the game as a pitcher. If you can keep a guy at first as long as you can, one pitch can get you two outs. That’s the only tough thing for me as a pitcher.”

He continues:

“Essentially, they’re making it easier for guys to steal bases,” Garland said. “They’re saying deception, deception. Well, isn’t that what you’re trying to do with everything? That’s why you throw different pitches – deception. You’re trying to get them out and you’re trying to do the best you can. But there’s always going to be changes in sports, especially for the better. Hopefully, it works out.”

Garland thinks the new rule will allow runners to take more extra bases. He thinks the new rule will reduce double plays. He thinks the new rule will make it easier to steal bases. All because the pitcher will be less able to keep a runner by the bag. The bigger the lead, and the greater the confidence, the better the base-running, or so the theory goes.

We don’t have any regular-season data. What we do have is a month’s worth of spring-training data, which, sure, it’s good enough. Why would these games be played differently? Let’s use this spring-training data to put Garland’s ideas to the test. What do we observe in 2013, as compared to what we observed between 2010-2012, in spring training?

  • 2010-2012: 34.6% runner scoring rate
  • 2013: 35.3% runner scoring rate

This is a very simple statistic, calculated as (R – HR) / (H + BB + HBP – HR). It isn’t perfect, but it’s close enough, and what we see is a small increase in the rate of base-runners scoring in 2013. However, 2013’s rate is slightly lower than 2010’s rate, and more importantly, the league ISO this spring is .165. The previous three springs, it was .153, and with more extra-base hits, it’ll be easier for runners to score. We’re not seeing much of anything here.

  • 2010-2012: 2.15% double plays
  • 2013: 2.28% double plays

What I don’t have is double plays per double-play opportunity. That would be ideal, but this approximation isn’t showing anything different. If anything, there’s a slight increase in double plays, not that I’m buying it quite yet. The previous three springs, there was one double play per 46 or 47 plate appearances. This spring, there’s been one double play per 44 plate appearances.

  • 2010-2012: 69.9% stolen base success rate
  • 2013: 70.0% stolen base success rate
  • 2010-2012: 1.1 stolen base attempts per game
  • 2013: 1.0 stolen base attempts per game

Base-runners have taken off slightly less often, and they’ve demonstrated pretty much the exact same success rate. Last year, they were successful just 67% of the time, but in 2010 they were successful 72% of the time so we can’t look at one without the other. I’m not seeing a stolen-base effect.

For my own curiosity:

  • 2010-2012: 91.3 innings per pickoff
  • 2013: 98.9 innings per pickoff
  • 2010-2012: 192.4 innings per balk
  • 2013: 178.1 innings per balk

We don’t see a dramatic decline in pickoffs, and we don’t see a dramatic increase in balks. And we’re dealing with very small sample sizes, so the error bars here are considerable. It makes sense that there would be slightly fewer pickoffs and slightly more balks, but not to an extent that changes the feel of the game.

Jon Garland expressed some concern over the potential consequences of the new balk rule. It’s far too early to say anything conclusive, and all we’ve got for now is spring-training data, but within the spring-training data, we don’t see anything alarming. We don’t see anything, really. Which is what we ought to expect. The new rule applies in only a fraction of all game situations, and any advantage to a base-runner would be on the order of a small fraction of one second. Sometimes that can make all the difference, but most of the time that makes practically zero difference. Does the new rule make things a little easier on base-runners? Sure, probably. But this seems like a case where the game will change without the game actually really changing.

We hoped you liked reading On the Consequences of the New Balk Rule by Jeff Sullivan!

Please support FanGraphs by becoming a member. We publish thousands of articles a year, host multiple podcasts, and have an ever growing database of baseball stats.

FanGraphs does not have a paywall. With your membership, we can continue to offer the content you've come to rely on and add to our unique baseball coverage.

Support FanGraphs

Jeff made Lookout Landing a thing, but he does not still write there about the Mariners. He does write here, sometimes about the Mariners, but usually not.

newest oldest most voted

The rule only has an effect when there are runners on first and third. It seems you’d need to extract only those situations before you could determine whether or not the rule made a difference in balk rate, scoring rate, etc.