By now, most baseball fans have probably heard about Kenley Jansen’s intentional balk. If you haven’t, let me catch you up to speed.
The rarity occurred on Friday night. It was the top of the ninth inning. The Dodgers held a 5-3 lead over the Cubs, and Jansen was on the mound to close out the victory. The inning started nicely, as Jansen struck out Carlos Gonzalez, but the Cubs did not go down cleanly. Thanks to an error from first baseman Matt Beaty, Jason Heyward reached second base. David Bote then struck out, leaving Victor Caratini as the only roadblock between Jansen and his 20th save.
The oddity commenced when Jansen yelled, “I’m going to balk,” following the strikeout of Bote.
And that’s exactly what he did, even going as far to award Heyward third base himself.
With Heyward now on third, Jansen completed the save with a Caratini strikeout.
The reason behind this move is fairly simple: with Heyward (or any runner) on second base, there exists a possibility that he could signal pitches or locations to the batter. Teams always change their signs with runners on base, but if Heyward managed to pick them up, then the Cubs could have been at a tactical advantage. Instead, with him on third base, the ability to steal signs is greatly diminished, if not impossible altogether. Because the Dodgers had a two-run lead, it did not matter on which base Heyward stood.
“It’s something Bob [Geren, Dodgers bench coach] and I have been talking about since spring training, but I keep forgetting to do it,” Jansen said, via Mike DiGiovanna of the Los Angeles Times. “I thought it would be a good time to try it.”
“I’m not saying the Cubs are stealing signs or tipping locations, but you always have to be on your toes… Whether you give up a bloop or a base hit, the guy is going to score from second with two outs.”
In the context of this game, the decision to balk made sense. The Dodgers’ win expectancy did not change as a result, sitting at 96.6% before and after the play. Therefore, by this logic, if Jansen determined that there would be any statistical advantage to having Heyward on third instead of second, it would be in his best interest to commit the balk.
The calculus of the situation changes, of course, if the balk would have had any impact on the outcome of the game. For example, let’s say that the balk decreased the Dodgers’ win probability from 96.6% to 94.6%, a two point drop. Jansen would have had to consider whether this drop was “worth it,” by calculating the odds that he could get Caratini out. If the change in odds of getting Caratini out with a runner on third base versus on second base did not outweigh the two point drop in win expectancy, then it would not be advantageous to balk. That’s why something like this only works in specific situations, and Jansen executed it to perfection here.
With something so rare and so new as an “intentional balk,” I had a few questions. Is there any defense to something like this? If he thinks it is to his advantage to stay at second base, could Heyward decline the balk? Or could he decide to return to second base later if he so desired? Let’s delve in.
First, based on the 2018 Official Baseball Rules, I give you the penalty for a balk. From Rule 6.02(a):
“The ball is dead, and each runner shall advance one base without liability to be put out, unless the batter reaches first on a hit, an error, a base on balls, a hit batter, or otherwise, and all other runners advance at least one base, in which case the play proceeds without reference to the balk.”
The word “shall” is important, considering that it can be defined in multiple ways which could alter the overall meaning of the sentence. In this context, it is likely being used to express a command. According to the Merriam-Webster Dictionary, it is particularly important to note when the word “shall” is used in a legal context. The word is “used in laws, regulations, or directives to express what is mandatory.” In short, a runner can’t decline a balk.
And, no, Heyward couldn’t have moved back to second base later in the at-bat. From Rule 5.09(b)(10):
“After he has acquired legal possession of a base, he runs the bases in reverse order for the purpose of confusing the defense or making a travesty of the game. The umpire shall immediately call ‘Time’ and declare the runner out.”
If Heyward had decided to go back to second, he would have been called out. That would be quite the travesty, if I’d say so myself.
So, in short, there’s really no defense to this. If a team is actually stealing signs, the intentional balk would be a great way to throw them off. Of course, as mentioned, it only works in specific situations. Most of the time, moving the runner up a base is never good. But in the case of Kenley Jansen on Friday night, he found the perfect opportunity to introduce something new to the game of baseball.
Devan Fink is a Contributor at FanGraphs. You can follow him on Twitter @DevanFink.