What, Exactly, Is a Jam?

A short while ago, on the Effectively Wild podcast, Ben and I took a few minutes to respond to a listener email about jams. That triggered a conversation about what a jam actually is. In a sense, I think we could all agree we know a jam when we see one, but I long for greater precision. Where’s the line between a jam and a non-jam? I didn’t have the answer. Ben didn’t have the answer. This is where you come in.

The Wikipedia glossary of baseball defines a “jam” as a situation “when runners are in scoring position with less than two outs and good hitters coming up.” The New Dickson Baseball Dictionary defines a “jam” as “a difficult situation during a game.” It continues: “Usually it is said that a pitcher is in a “jam” when the opposing team is in a position to score, such as when the bases are loaded with no outs.”

Here’s a reference to Zach Davies being in a jam with the bases loaded in the bottom of the first. Here’s Jameson Taillon in a so-called jam with two on in the bottom of the fifth. Here’s Brett Cecil in a bases-loaded jam in the bottom of the eighth. Here’s a random reference I found to a Brandon McCarthy jam in the third, when he kicked a frame off with a double and a walk.

Some situations are very obvious jams. Some situations are very obvious non-jams. I’m interested in the in-between, and this screams for a FanGraphs community polling project. As such, below, you will find 12 very simple polls. Each poll describes a different game situation. Assume, under all circumstances, that we’re dealing with average, regular players. Each poll then asks a yes-or-no question: Is the situation described a jam? Don’t worry about right or wrong answers. Just go with your gut. Your collective guts will lead us to some kind of truth.

I’ll analyze the results later on, if it indeed seems like they’re worthy of analysis, which I assume they will be. Thank you in advance, and, happy polling. It’s time to define the undefined.













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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.

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i was hoping this post would just be a youtube video of this song