On Sept. 9, young Diamondbacks starter Braden Shipley threw a fastball low and inside to Giants ace Madison Bumgarner, who took it for a ball. Bumgarner backed out and glanced toward third base for a sign, which was delivered and received in about a half-second. Bumgarner stepped back in, left hand gloved, right hand bare, his left fingers flexing around the bottom of the bat handle as he waited for the pitch.

When it came -- a 92 mph fastball over the heart of the plate, in the upper half of the strike zone -- Bumgarner took a huge rip and fouled it back, making the count 3-1. The Arizona broadcast booth broke into laughter.

Bob Brenly: How many pitchers get the green light three and oh?

Steve Berthiaume: One.

Both, overlapping: One!

Brenly: That's right. That's right.

Or is it?

Pitchers have always been terrible hitters, but they're only getting worse. Relative to the league's average offense, 2016 was the third-worst year for pitchers at the plate, coming on the heels of their all-time worst 2015 performance. Pitchers bat less frequently than ever, of course, a byproduct of shorter outings. But beyond that: If we assume that performance within a meritorious system gets better over time -- that scientists get better at science, doctors get better at medicine, baseballers get better at baseball -- we would expect pitchers' hitting to get "worse" relative to their nonpitching peers. The pitchers they're facing are getting better. The actual hitters they're being compared to are getting better. They, meanwhile, are not selected for their hitting skill, and they put minimal effort into being the best in the world at it. (Pitchers' hitting is not a meritorious system.) So they stay relatively the same, and look worse:

Bumgarner, and a very few others, are exceptions. After a slow start to his hitting career -- he batted only .138 with two homers through his first four full seasons -- he took off in 2014. His aggregate performance since then doesn't look like any other major leaguer's, with its heavy emphasis on power at the expense of contact or on-base ability -- but a .227/.275/.428 line in a pitcher's park can hold up in a major league lineup. His .304 weighted on-base average (wOBA) over the past three years is better than those of scores of major league regulars, including Javier Baez, Desmond Jennings, Sal Perez, Kolten Wong, Danny Espinosa, Jason Castro and many more players who wouldn't be as impressive in a list like this. He is a fun-fact machine:

Babe Ruth career

Innings pitched: 1,221⅓

HR hit as a pitcher: 13



Madison Bumgarner career

Innings pitched: 1,251

HR hit as a pitcher: 13 — Ryan M. Spaeder (@theaceofspaeder) June 2, 2016

In addition to this, Bumgarner is a good story. There are the times his manager Bruce Bochy uses him as a pinch hitter. (He started a rally with a double.) There was the time Bochy let him "DH" for himself in an American League park. (He started a rally with a double.) There was the debate over his wish to appear in last summer's Home Run Derby. And, now you know, there's the 3-0 green light.

The previous batter, Eduardo Nunez, had singled but had hurt himself running to first. After a long visit from the trainer and much stretching, Nunez stayed in the game. A safe assumption is that Nunez would be station-to-station, unable to score from first on a double or from second on a single.

The game was tied and there were two outs in the sixth. A walk from Bumgarner would put Nunez on second, where there's no guarantee that it wouldn't still take two hits to get him home. It would also put Bumgarner on first with two outs, but even an average baserunner scores only about 13 percent of the time after reaching first base with two outs. The benefits of a home run relative to a walk, then, were a bit exaggerated by the situation. Shipley is prone to home runs -- his HR/9 rate was 60 percent higher than league average -- and Arizona's ballpark is prone to them as well. Bumgarner got a hammerable pitch from a hammerable pitcher, and he just missed it.

It was not quite the break from tradition that Brenly and Berthiaume implied. The 2016 season, among other things it won't be remembered for, was the year that the Pitcher's 3-0 Green Light exploded, relatively speaking.

Broadcaster 1: And how 'bout a green light on three and oh?

Broadcaster 2: Why not? Pretty good pitch.

Broadcaster 1: What percentage of pitchers get a green light on three and oh?

Broadcaster 2: Not that many.

Arrieta doesn't seem to have looked for a sign on the pitch, either into the dugout or to a base coach. Unless there was a verbal encouragement from the coaching staff, he swung on his own. There were two outs and nobody on, and the Cubs were leading 3-0 in the second inning. Arrieta entered the game hitting .276/.323/.448, which probably isn't his true talent level but compares favorably to, say, Eric Hosmer's .266/.328/.433 line. The pitch itself was probably not worth swinging at, though:

May 3: Arrieta against Jon Niese

This time Arrieta does look into dugout before the pitch, for about five seconds, presumably waiting to get Joe Maddon's attention so he can get the swing-away clap-clap. He seems to have gotten the clap-clap, with one out and a runner on first, and with the Cubs already leading 6-0.

The Cubs announcers aren't as surprised by this as our previous announcers were, because just one week earlier ...

April 28: Arrieta against Taylor Jungmann

Broadcaster 1: And the pitcher swinging three and oh. Cubs are feeling good, aren't they?

Broadcaster 2: That's about as obvious a sign as you could have.

Broadcaster 1: I don't think I've ever seen a pitcher swing 3-0.

Again, the Cubs are ahead, 3-0 in the second inning. The previous batter had homered against Jungmann, whose season ERA was 9.50 when Arrieta dug in. The pitch was not necessarily in the strike zone, but considering how generous umpires are on 3-0, it probably would have been called one. Arrieta fouled it off. He fouled off all three of his 3-0 green lights.

Broadcaster 1: He was swinging on 3-0!

Broadcaster 2: When is the last time ...

Broadcaster 1: NEVER! That's the last time.

Broadcaster 2: ... you've seen a pitcher swing at three balls and no strikes? Come on, Don Mattingly.

Broadcaster 1: Never seen that. I mean I'm sure it's happened.

Fernandez swung and missed.

So we have five instances of pitchers swinging at 3-0 in 2016. Is that a lot?

In 2015, only one pitcher did: Bumgarner, against Ian Kennedy in Arizona. He was one home run away from tying the Giants' franchise record for home runs by a pitcher in a season. He fouled it off.

Broadcaster 1: How 'bout that. You green-light the pitcher 3-0.

Broadcaster 2: Well, with five home runs on the year, why not? You know he's got the power. You know you're gonna get the fastball.

Broadcaster 3: Yeah, let the big dog eat!

In 2014, only one pitcher did: Bumgarner, against Franklin Morales in Coors Field. He fouled it off.

Broadcaster 1: Well, that's respect from a manager saying I know he's gonna get a fastball, and I know he can hit a fastball.

Broadcaster 2: Walt Weiss just looked at Rene Lachemann and said "really?" It's not something I've ever seen before.

In 2013, no pitcher did. In 2012, in 2011, in 2010, no pitcher did. In 2009, Mike Hampton hit a sacrifice fly on a 3-0 count in the middle of a blowout. In 2008, no pitcher did.

That's the PITCHf/x era: One 3-0 swing in the first five years, then one per year in 2014 and 2015, and five this year. In the decades before PITCHf/x, we can find instances of pitchers being credited with swings on 3-0 in game logs, but there's no way to know if those records are reliable. The quality of the hitters credited with 3-0 green lights makes me very skeptical, and in no case -- even cases where game logs say pitchers got hits on 3-0 -- could I find confirmation of the swings in the next day's game stories. We have bumped up against what we can know. The deep history of pitchers swinging 3-0 is mysterious and will remain so. The applicable history of pitchers swinging 3-0, then, is young and developing.

We have watched seven 3-0 green lights and heard seven reactions from seven different broadcast booths. There are two themes in these reactions: LOL, I've Never Seen That Before and Hmm, But Sure, Why Not?

But sure, why not? Generally speaking, I don't think there's a great strategic reason to give more pitchers (or even these pitchers) green lights on 3-0. We shouldn't forget that Bumgarner is a good hitting pitcher but a bad hitter. His .275 OBP over the past three years is terrible. His strikeout rate over the past three years is worse than any nonpitcher's, minimum 250 plate appearances. And we could hypothesize that he's not actually as good as his past three years' performance. His good years are a small sample, after all, and the 265 terrible plate appearances he had before 2014 aren't irrelevant. His 2016 season was quite a bit worse than the previous two, so regression might have already taken hold. (Counterargument: He seems to be learning the strike zone, so maybe he'll get better.)

But it's probably best not to view these seven green lights as strategic. Most came in low-stakes situations, they were granted to staff aces, and they were given to pitchers who have shown they take their hitting seriously. In one sense, they can be viewed as rewards to pitchers who don't treat this part of the sport as an afterthought. If you're Maddon and you see Arrieta looking in at you, eager to hit a baseball a long way, enjoying where he is and what he's doing, why not clap-clap? Why not let the players have fun?

What I'm going to say next is all anecdotal, and I don't know how one would design a study to prove it, but: Sometime in the past few years, the culture of baseball on the field started to allow for fun again. It's not always a peaceful transition, as we've seen in instances where celebrations and excessive spirit led to brawls or retaliation. But it's thawing. Many of the game's best young stars -- Lindor, Baez, Betts -- seem always to be smiling. Teams all have their silly memes, their home run tunnels or their post-hit hand motions to the dugout. Nobody embodied this thaw quite like Jose Fernandez, whose obituaries invariably mentioned the joy he had, and how refreshing it was.

The pitch after he whiffed on 3-0, Fernandez got another fastball, up, and took an even bigger swing. He fouled it off, then unleashed a spray of excited Spanish. He really wanted to hit a home run, and if there's anything we should all celebrate in baseball, it's pitchers who really want to hit home runs. Bless the managers who let them try.