On the ball field there’s only one language that matters — baseball

He may not speak English fluently, but Koji Uehara doesn't need English to be fluent in the language of baseball.

It's as easy as: A, B, C. Or, rather make that: one, two, three.

"One finger is a fast ball; sometimes that index finger'll get swirled, that'll mean a two seam fastball; sometimes there'll be a sharp knifing motion, that means cut fastball. Then there's two fingers, usely a curveball or breaking ball, three fingers means…" said Dirk Hayhurst, a retired Major League Baseball pitcher who is fluent in the language of baseball.

Hayhurst can go on and on. Maybe it's not so easy after all.

All those swirling fingers and knifing motions are the way catchers speak to him. In fact, Hayhurst pitched many, many games in the minor leagues to a catcher who hardly spoke a word of English.

"We just broke camp from spring training and we're driving the team bus and he's sitting on the bus reading a book called English for Dummies," Hayhurst recalled.

On the field, though, he was certainly no dummy.

"You spend one week throwing to this guy and he knows what to do," Hayhurst said.

A pitcher and catcher learn from one another just by flashing a series of ones, twos and threes. But it goes beyond mere hand gestures, says Hayhurst. Speaking the language of baseball also means knowing the unwritten rules of the game.  Rule number one: you don't peek. That means the batter can never look back at the catcher to look at signs. 

But if a batter did steal the signs — when Hayhurst was pitching to his Spanish-speaking catcher, language wasn't an issue.

"My catcher, who doesn't speak a lick of English outside of these baseball rules, said, 'He peeking! He peeking!'  And my next pitch was high and tight and I put this guy in his place," Hayhurst says. "I don't think he read that in the English for Dummies book."

When you want to nail someone, Hayhurst says, the sign is an over-turned palm with the thumb gesturing angrily. 

So what are the origins of the baseball signs?

"The basis for signs and signals and sign-stealing pretty much go back to the American Civil War," said Paul Dickson, author of The Hidden Language of Baseball.

Baseball was played before the Civil War, but coded hand signals became a common tool for soldiers on the battlefield trying to communicate with one another. Coded signs and signals were used by both the Confederate and Union armies. After the war, those coded signs were carried from the battlefield to the ballfield. The jump from soldiers in battle to men on a field isn't a hard leap to make, says Dickson.

"The manager, who is the field general, is in uniform and he's directing, the first and third base coach are the first lieutenants, the catcher is the sargeant directing the men in the field [and] the pitcher and catcher are the battery," Dickson said.

Signs were not only meant to communicate with allies but to confuse the enemy who was actively trying to break the code. Just as the unwritten peeking rule is universa,l so it seems is the act of decoding the opposing team's signs. And throwing "deeks," or decoy signs — that's part of the game, too.  

"You have to disguise your signs. You've got your poker face out there in front of the world," said Joe Vavra, a third base coach for the Minnesota Twins

Vavra has a pretty good poker face, and a good memory. While he's throwing out deeks, he also has to remember the real signs for each player on the team as well as teach them the signs.

"We'll go over them, we'll go over them, we'll go over them," Vavra said.

As for teaching the players who don't speak English. Who needs it? Vavra just mimes the movements for the players who aren't completely comfortable in English.

"I can show them the actions and they understand," Vavra said.

Still not every play in baseball can be reduced to a tap on the forehead or a brush of the arm. Language is sometimes necessary, like during a mound visit when players and the coach come together to discuss strategy.  What happens when everyone speaks a different language? Hayhurst says yes, sometimes, you just have to bring the interpreter to the mound. But even then the situation is not quite clearcut.

"The interpreter will speak and the shortstop will try to reinterate what the interpreter is trying to reiterate from the coach to the second baseman who speaks really only fluent Japanese," Hayhurst said. "And the funny thing is, is whether the Japanese second baseman understands or not, he will be bowing his head over and over again, which confuses the American coach because that's a sign that [the Japanese player] understands."

But the Japanese player may just be bowing his head as a sign of respect toward the coach.

"So it can be a recipe for disaster, it really can," Hayhurst said.

Still, oddly enough, he says more often than not miscommunication has nothing to do with a player's native tongue. In fact, according to Hayhurst, when two players do not speak the same native language they can actually be more attentive and careful when reading the signs.

"I've seen guys mess up signs who speak the same language way more than I see problems with guys who grew up 3,000 miles away from each other," Hayhurst said.

So this weekend, when you're watching the series, be on the lookout for the verbal and the nonverbal signs. There's a whole lot language going on.

A previous version of this story incorrectly spelled Dirk Hayhurt's last name.