On May 12th, in the first inning of the Cubs’ game against the White Sox, Jon Lester did something a little bit unusual: he swung at a 3-1 pitch. Now, if Jon Lester were not a pitcher, that wouldn’t be all that unusual. Since 2011, non-pitchers (another word you might use for these people is “hitters”) have swung at 3-1 pitches about 56% of the time — 55.9% of the time, to be precise. But Jon Lester is a pitcher, and he still swung at a 3-1 pitch. And the thing is, over the same time period — that is, from 2011 (when our data starts) to present — pitchers faced with 3-1 counts have swung at the next pitch just 38.3% of the time. Of those swings, just one in five was at a pitch outside the zone, like the fastball on the outside edge at which Lester swung and missed. It’s just not something you see that often.

That’s because, if you’re a pitcher, swinging at a 3-1 pitch is usually not a very good idea. If you swing at such a pitch, you might get a hit (pitchers did hit 27 home runs last year, after all!), but you might also put the ball in play and record an out. If you don’t swing on 3-1, you definitely won’t record an out. You might still get a strike called against you, which would put you that much closer to recording an out, but you might also walk or get hit by the pitch — and a walk or hit by pitch, for a lot of pitchers at the plate, is a very good outcome. Last year, pitchers took 5,277 plate appearances. They recorded outs in 4,522 of those plate appearances (85.7%). I think it’s fair to say pitchers are looking for any means to reach base available to them. Swinging at 3-1 pitches is not a good way to do that. And so, two-thirds of the time, pitchers don’t.

Everything I’ve just said applies doubly to 3-0 counts. Even regular hitters don’t swing at those pitches all that often — just 8.2% of the time since 2011, in fact. With two strikes still available, it just doesn’t make any sense not to give the pitcher a chance to walk you, and so upwards of nine times out of 10, hitters will let the pitcher prove he can find the zone on a 3-0 count. And when it’s a pitcher at the plate, the odds of a swing on 3-0 are even smaller. Vanishingly small, in fact. Thanks to a database query performed by my colleague Sean Dolinar, I’m able to report to you now that a pitcher swing on a 3-0 count has happened only seven times since 2011, or about once a season. Seven times, out of 578 opportunities. About 1 in every 100 times. Almost never. And — here’s the fun thing about this story, I think — six of those seven swings were taken by just two men, and all seven came in the span of just three seasons. Let’s investigate the history of this strange baseball phenomenon together, shall we? Come with me on a journey back to May 20th, 2014.

Whoops! I jumped ahead in the story a little bit. That there on your screen, right above this text, is Madison Bumgarner of the San Francisco Giants swinging at a 3-0 pitch in the fifth inning of a game against the Colorado Rockies. Now, Bumgarner can hit a little bit — at least as well as the worst big-league hitters can hit, that is. His career wRC+ is identical, for example, to Drew Butera’s. And he was behind in this game 1-0 in the fifth, with two runners on base and an out in the inning to spare. Perhaps he felt that his cause would be best served by a Very Large Home Run against Franklin Morales, who at this point in the game was pitching a gem (those of you who are familiar with the life and work of Franklin Morales may not be shocked to discover it did not end that way, though it wasn’t a terrible start, on the whole).

Anyway, for reasons either public or private — and in any event undisclosed in the years since — Madison Bumgarner decided to swing at the 3-0 pitch, did, and very nearly fell over in the process. Which kind of makes sense. This was the first time something like this had happened since at least 2010, and was sufficiently disconcerting to Wilin Rosario, behind the plate, that he went out to talk to Morales on the next pitch, and left Bumgarner to pace and think about what he’d done.

Two pitches later, Bumgarner struck out, an experience which he probably did not enjoy. Something like that can stick in your craw for a little while — and maybe it did. In any event, about 16 months later, on the 24th of September, 2015, against another NL West opponent, Madison Bumgarner once again found himself at the plate down a run and with a runner on base. He once again found himself with a 3-0 count. And he once again did this:

In one sense, this also sort of makes sense. In a 3-0 count, against a pitcher, a pitcher is likely to throw a fastball — or, at the very least, a pitch right down the middle. Nobody wants to be the guy who walks the pitcher. Before swinging at the Ian Kennedy pitch you just saw above, Bumgarner had experienced 11 different 3-0 counts from in the years from 2011 onwards. Eight of those 11 times, the next pitch was in the strike zone (including the one at which he swung on May 20th of the previous year). Bumgarner has a little bit of power. Maybe he was trying to run into one. Maybe he was trying to get the lead. It’s not the worst idea in the world. In any event, he missed. On the next pitch, he grounded out. Let’s move on. The next swing is not from Madison Bumgarner.

My take on this swing is that José Fernández had every intention of hitting this pitch approximately 10,000 feet. He was, unfortunately, just a little bit late. But by choosing to swing at this pitch from Aníbal Sánchez, he has lent credence to my working theory that pitchers facing deficits in the middle innings are more likely to swing at 3-0 pitches than pitchers not facing deficits, especially when there are runners on base. That would only make sense, right? These are competitive people, and they want that pitcher win, whatever you and I might think about it. Yes, I’m beginning to think this theory makes an awful lot of sense. I’m very smart! Good job, me! For no reason at all, let’s examine the next two instances of a pitcher swinging on 3-0 together.

Ah. I guess there are pitchers who wait for a decorous time to swing at a 3-0 pitch, when such a swing might give their team the lead. And then, on the other hand, there’s Jake Arrieta, who’ll swing at a 3-0 pitch even when his team is up six runs. Incidentally, that first GIF (from April 28th, 2016, against the Brewers) is the only example we have — in fact the only example in the universe, dating back to 2011 — of a pitcher swinging at a 3-0 pitch that probably wouldn’t have been called a strike. This suggests to me that Arrieta had just decided ahead of time he was going to swing at 3-0 and didn’t particularly mind that the pitch in question ended up inside. The second GIF is from just five days later (!), in Arrieta’s May 3rd start against the Pirates, and represents perhaps a big man’s conviction that, one of these days, he is going to hit a 3-0 meatball out of here. Poor Jon Niese had very little idea what was coming for him.

Neither, either, did Braden Shipley, later that September — but perhaps he should have. On the ninth day of September, 2016, Madison Bumgarner once again come up to the plate against an NL West pitcher in a close game with a runner on base, once again ran the count to 3-0, and once again decided that this moment was his to seize.

I can’t say things went much better for him this time than they did either of the first two times — the swing generated yet another foul ball — but I am delighted to discover that his strategy has remained so completely consistent through the years. Let’s move on to the one after 9/09:

Once again, Jake Arrieta is here to mess with my theories. This is the bottom of the second, for crying out loud, and the Cubs are up by three runs against the Brewers on the 17th of September, 2016. Zach Davies has missed down and away three times, perhaps hoping Arrieta would roll over on one, and on the 3-0 pitch Arrieta finally bites and fouls it off. It’s not a bad strategy, because Davies was repeating himself, but as in all six other cases, this one didn’t pay off for him. On the next pitch, Arrieta grounded out. And here endeth the data-collection portion of our tale.

Now, seven swings are not enough — not nearly enough — of a sample from which to extract any credible theories, but what the hell. Let’s get crazy. Here are a few of my working theories of pitcher swings at 3-0:

Star pitchers are more likely to swing 3-0. If you’re, say, a rookie making his major-league debut on the mound, it seems unlikely to me that you’d want to swing at a 3-0 pitch. That’s because swinging at a 3-0 pitch is generally not a good idea, and you’ll probably get an earful from your manager or teammates if you do it. Established starters seem more likely to be willing to take that risk than pitchers still wondering if they have a secure spot in the rotation. Good-hitting pitchers are more likely to swing 3-0. This is just common sense. If you know you don’t have the strength or coordination to crush a meatball if you get one, why bother swinging 3-0 at all? Arrieta, Bumgarner, and Fernández are or were known for their ability to hit the occasional home run at the plate. I doubt you’d see a pitcher with zero career home runs give this kind of swing a try. A 3-0 swing is generally premeditated and somewhat predictable. I’m intrigued by the fact that all three of Bumgarner’s swings came with his team behind or tied, and runners on base, and all three of Arrieta’s swings came with his team comfortably ahead — and no runs allowed. This suggests, to me, that both men decided in advance they would be swinging 3-0 in those particular situations, contrary to their usual default of not swinging in other situations. Knowing what I know about Arrieta, I’m guessing that being up in the game by a comfortable margin makes him feel pretty good about himself, and he decided in all three cases that he might as well try to make a good day extra special by adding a dinger to the box score. I’ve not met Bumgarner, but it makes sense to me that he would decide three times, with his team down or tied in the mid-innings, that he was as good a man as any to correct the score in his favor. I would be very surprised if any future 3-0 swings from either man broke the patterns we’ve seen established here.

Those are my theories. But they’re just theories, and for a few months now they’ve suffered from a notable lack of further data. Since September 2016, baseball has not seen a pitcher swing at a 3-0 count. It didn’t happen once during the entire 2017 season. It hasn’t happened yet during 2018. That’s not to say it couldn’t happen again — Arrieta and Bumgarner are still playing, after all — it’s just to say that it’s rare. Look out for it, would you? It’s one of the rarest sights in all of baseball, and I for one am ready to learn more.