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.

29 Comments
Oldest
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cwhitman
9 years ago

i was hoping this post would just be a youtube video of this song
https://www.youtube.com/watch?v=TeccAtqd5K8

Danny MiddaughMember since 2023
9 years ago

I think some of the borderline ones depend on the game too. There’s probably less jams in an April game than a September game for a team in a playoff race.

AC_Butcha_AC
9 years ago

I think you should include who is coming up to the plate as well.

I gues Leverage Index Should do a decent job of defining a “jam” even though batting order is ignored.
Usually a pitcher tries to navigate through a line-up, get the guys out he is supposed to get out and don’t let the big guys in the middle beat you. If a pitcher loads the bases with the 8-9-1 hitters he didn’t do his job and now you have 2-3-4-5 coming up who you will have to give a chance to beat you …

murphsky
9 years ago

I think a jam should be defined in terms of the probability an opposing team has to score at least one run, or in terms of the expected number of runs in a given situation (http://www.nssl.noaa.gov/users/brooks/public_html/feda/datasets/expectedruns.html).

NoHayBanda
9 years ago
Reply to  murphsky

Yup, came in here to say this. But it does miss some context as others have mentioned. (Corners, 1 out in a 12-2 game is not a Jam imo)

ScoreboardMember since 2016
9 years ago
Reply to  NoHayBanda

So can we take murpshky’s definition and just say run differential is less than or equal to 4?

Beep Boop
9 years ago
Reply to  Scoreboard

I typically think of Jams as a situation a pitcher has put himself into, as opposed to a reliever coming in with lots of inherited numbers. Because of that, I feel that putting too much emphasis on context (inning, score, standings) might take too much away from a hypothetical “Jam Index”

That said, if something is to be quantified, I would say that it should be based on a blended or scaled combination of the following:
Expected number of runs before the third out of the inning
Change in expected win % as a result of the expected runs.
There might also be “extra” penalties for allowing game tying or go-ahead runs, and maybe extra weighting for increased “excess” runs allowed, but that may be double dipping.

murphsky
9 years ago
Reply to  NoHayBanda

Fair enough. You’re right, I would feel weird calling situations like that one a jam. But I will say that the more context you factor in, the harder it will be to make any sort of numbers-based definition.

Joe Joe
9 years ago

2 or 3 men on. Pitching team is ahead by # of base runners + 1 or less or behind by 1-2 runs.

olethrosMember since 2020
9 years ago

Situational jamminess is proportional to the probability of the go ahead run scoring on any given pitch, with additional jam points given for each man on base beyond the go ahead run.

grandbranyanMember since 2017
9 years ago

Buncha dudes, some instruments, cold brews, etc…

or

Not exactly a jelly, certainly not a preserve & nowhere near a marmalade.

Moltar
9 years ago

If you get out of a jam, it should be called a preserve.

Deacon DrakeMember since 2017
9 years ago
Reply to  Moltar

That is how a legend is born…

Beep Boop
9 years ago
Reply to  Deacon Drake

The sweet spread of internet fame.

Jay_B
9 years ago

I hadn’t really thought about it, but according to my gut answers, there pretty much has to be a guy on third for it to be a jam. Probably even 2nd and 3rd.

YKnotDisco
9 years ago

I can’t help but hear George Clooney’s voice saying: “Damn! We’re in a tight spot!

Six Ten
9 years ago

The easiest way to articulate what appears to be my rule of thumb is: the highest number of runs that can score without either a home run or consecutive successful plate appearances must be at least one-third as many innings as remain in the game.

So, for example, in a bases loaded, one out tie in the first inning sets up the following possibility: base-clearing double, plus a fly out, plus another hit, plus another out. That’s likely to produce four runs with fewer than nine innings to play, which makes it a jam. It’d also be a jam with two outs, since the bases-clearing double still leads to a three-run lead with fewer than nine innings to play. If there were only two men on, however, you couldn’t have two outs, since that could produce only two runs without either a home run or consecutive batters reaching safely.

My thinking for that is basically this: it’s not a jam if it’s unlikely to pose a major threat to your ability to win on its own. And it’s not a jam if you can play the percentages by nibbling around the strike zone without posing a major threat to your ability to win. And it’s not a jam if it takes someone demolishing a baseball to beat you, since someone demolishing a baseball is just the case of them being way better than you in that moment. That’s just a small-scale version of a bad team playing a good team.

If, on the other hand, a bloop hit or two can beat you, then yes, that’s a jam. That means you can make the best pitch available to you, and the batter can fail to connect with it, and you can still lose. If they get more than two bloop hits in a row, well, baseball is weird and/or you are playing the 2015 Royals, and there’s nothing you can do about either of those things. A jam is a situation you can’t escape without getting a little bit lucky.

Choos on first
9 years ago

We could also use one of the save conditions as a rough estimation of whether or not it’s a jam:

He enters the game, regardless of the count, with the potential tying run either on base, at bat or on deck

Basically, any pitcher who puts themselves into this scenario has put themselves in a jam, and reliever coming on to replace a pitcher in this scenario has to work out of a jam he inherited. This is why I voted ‘Yes’ on #2.

BipMember since 2016
9 years ago

I don’t think I have strong personal feelings about what a jam is, nor what it ought to be, but I think I have at least heard the term used for literally any situation with a runner in scoring position. The least worrisome of all such situations is when a pitcher retires the first two batters, allows a double, and then retires the next batter, and I feel even then I have heard an announcer say the pitcher “escaped a jam.”

Announcing is hard. They have to say a hell of a lot of words about crap which has mostly all happened before, even more so if they are on radio.

I think maybe a criteria is that the worst-case outcome of a jam will result in a close game or otherwise greatly change the win expectation of a game. In the above situation, I don’t think anyone would say “jam” with the pitching team up 8-0, but if that runner is the tying or go-ahead run, they might.

BipMember since 2016
9 years ago

Also, I hope you chose some of these examples knowingly with regard to leverage or win probability, to illustrate how “jams” are biased towards situations where change seems more likely, even when that change has less impact on the game. Like, bases empty, no-out, bottom-9, the leverage is as high as the situation with runners on in the earlier innings, right?

Jon
9 years ago

I’m probably in the minority here, but to me, just thinking in terms of my gut reaction, it has little to do with the score, and more to do with the individual situation.

For example, if my team’s up by 8, I’m pitching and have the bases loaded with no outs and Mike Trout coming up, then I think I’m in a jam, even though the game isn’t really on the line (yet).

I also feel pretty strongly that multiple runners need to be on. If you’ve got a runner on 3rd with no outs in a tie game, that could be a “tough situation”, but I have a hard time calling that a “jam”. Who knows, maybe it’s my subconscious making a parallel between the word and the idea of the bases being “jammed”?

So, in terms of factors, I would say:
1) score/inning – not important
2) runners on – generally must be at least 2, and I’d say in most cases one of them must be on 3rd.
3) number of outs – a jam is possible with any number of outs, but the fewer the outs, the more “jammy” it is
4) hitter at bat (and hitters after him) – definitely relevant.

So to sum up, in general I’d say the amount of a jam the pitcher is in is proportional to the number of runs the opposing team is expected to score in that inning, after taking into consideration the quality of the hitters coming up.

Deacon DrakeMember since 2017
9 years ago

Momentum

From a pitching perspective, things are much more tense when a) there is a runner on third, b) no place to put the batter, and c) unlikely to get out of the inning on one pitch. These affect the pitch that can be called, where it can be thrown, and with what kind of conviction (i.e. buried slider, inside fastball).

Situation applies to the whole team and while I think that the burden affects the pitcher, like a tight game late, the three things above amplify the tension directed to the pitcher.

For instance, nobody would really feel that bases loaded, 1 out in the 6th of a 6-0 games is all that tense, but a base clearing double totally changes the complexion of that game, as suddenly we would be in a save situation as opposed to a runaway. Even with just 2 runners on (either first or third base empty) it increases the arsenal of what can be thrown with less risk to build momentum for the other team. That’s what you want to avoid.

9th inning and beyond is kind of it own animal though.

thephantomblotMember since 2017
9 years ago

I think if 2 or more runners are on, that’s a jam. Period. Regardless of game situation.

I think in a close game (+/- 1 run), 7th inning or later, a single runner in scoring position can also be considered a jam.

Jason BMember since 2017
9 years ago

From my vantage point, no 2-out situation can be a jam. I generally consider a jam as multiple men on base, needing to record >1 out to escape.

Score/game situation to me is irrelevant. A pitcher to me is still in a jam with the bases loaded and 0 outs, even up 12-3 in the 7th. The game shouldn’t be in doubt even if he cedes a run or two, but he himself, at that moment, is in a jam. I guess I’m saying I consider it pitcher-specific and not team-specific.

Doorknob11
9 years ago

Somebody said nobody on no outs is a jam. Some people just want to watch the world burn.

chrisjacoby
9 years ago

What about when a batter gets jammed by an inside pitch when the pitcher is in a jam?

Majtom18
9 years ago

I love the notion of a site that is SO bent on statistical analysis and logic using “gut reactions” to try to quantify something. I really liked this poll, would enjoy seeing more like this in the future

Michael
9 years ago

A Jam is a thick spread made from fruit juice, chopped, crushed, or puréed fruit, and sugar. Pectin may also be added to help it gel, but jams are usually looser than jellies. Jam typically contains a bit of fruit pulp, so it’s not entirely transparent.

Jelly, on the other hand, is a clear fruit spread made from cooked fruit juice and sugar, and possibly pectin, which helps it gel and thicken. After the initial cooking, jelly is strained through a muslin stockinette or “jelly bag” to remove any solids.