So what is being 'stolen' is something that largely comes down to a 50% probability in most situations?
People like to say this, and cite statistics and measurements for it, but it's true: hitting a ball thrown by a major-league-caliber pitcher is one of the most difficult feats in sports.
For a good major-league-caliber fastball, the total time available, from when the ball leaves the pitcher's hand to when it's past the batter and no longer possible to hit, can be around 400ms. And even for well-trained professional hitters, the time necessary to make a decision and swing the bat far enough around to make contact is around 300ms.
That means a major-league hitter has essentially 100 milliseconds, after the ball leaves the pitcher's hand, in which to decide what to do. This means it's not possible to spend time watching how the ball moves; if you do that, it will already be past you by the time you make a decision.
So major-league hitters rely on a combination of whatever information they can get in that 100ms of observation on each pitch, plus whatever they saw just before (pitchers try their best to be consistent no matter what pitch they throw, but there can be visible differences in arm angle and grip which provide extra information), plus known patterns both of pitchers in general and of the specific pitcher they're facing.
And even with all that, the best hitter of all time -- Ty Cobb -- had a lifetime batting average of .366. A batting average of .400 or better in a single season hasn't happened in over seventy years.
So yes, any extra information is a big deal. Just knowing what type of pitch is about to be thrown is a huge advantage to the batter, because it provides so much more time to think about what to do and act on the decision.
As to your other questions: "stealing" signs is perfectly legal and has a long history in baseball, but as the article notes the rules forbid the use of technology to assist in it. The batting team generally can only do it when there's a runner on second base (able to look directly at the catcher and see the signs), and teams always switch their system of signs in that situation to try to make it more difficult.
People like to say this, and cite statistics and measurements for it, but it's true: hitting a ball thrown by a major-league-caliber pitcher is one of the most difficult feats in sports.
For a good major-league-caliber fastball, the total time available, from when the ball leaves the pitcher's hand to when it's past the batter and no longer possible to hit, can be around 400ms. And even for well-trained professional hitters, the time necessary to make a decision and swing the bat far enough around to make contact is around 300ms.
That means a major-league hitter has essentially 100 milliseconds, after the ball leaves the pitcher's hand, in which to decide what to do. This means it's not possible to spend time watching how the ball moves; if you do that, it will already be past you by the time you make a decision.
So major-league hitters rely on a combination of whatever information they can get in that 100ms of observation on each pitch, plus whatever they saw just before (pitchers try their best to be consistent no matter what pitch they throw, but there can be visible differences in arm angle and grip which provide extra information), plus known patterns both of pitchers in general and of the specific pitcher they're facing.
And even with all that, the best hitter of all time -- Ty Cobb -- had a lifetime batting average of .366. A batting average of .400 or better in a single season hasn't happened in over seventy years.
So yes, any extra information is a big deal. Just knowing what type of pitch is about to be thrown is a huge advantage to the batter, because it provides so much more time to think about what to do and act on the decision.
As to your other questions: "stealing" signs is perfectly legal and has a long history in baseball, but as the article notes the rules forbid the use of technology to assist in it. The batting team generally can only do it when there's a runner on second base (able to look directly at the catcher and see the signs), and teams always switch their system of signs in that situation to try to make it more difficult.