In 1920 the spitball was outlawed in baseball. Arguably this was in response to the death of Ray Chapman of the then Cleveland Indians, who was hit with a ball and killed while at the plate. Witnesses state that he never attempted to avoid the ball, which led to speculation that he never saw it coming. This was the end of the era known as the dead-ball era in baseball, which I wrote about previously in “Into the Swing of Things”.
The dead-ball era was characterized by the use of balls that literally wore out and died during the game, because they were practically never replaced. Knowing this, every pitcher considered it his responsibility to hurry along the death of the ball with the application of any and every substance possible: spit, tobacco juice, grease, licorice, sand paper, nail files, nails, blades, spikes, you name it. Dead balls were hard to see clearly. It is unknown if the ball that hit Chapman was simply dead from over use, or if the pitch was a spitball, as many speculate. According to the Society of American Baseball Research, pitcher Carl Mays was famous for his spit ball (then legal), and the sound of the ball hitting Chapman’s skull was so loud that Mays thought the ball had been hit by the bat, fielded it, and threw it to first. Chapman died twelve hours later. His team went on to win the World Series.
Spitballs were banned that year. Batting helmets were not made mandatory until 1971.
Since 1920 we have been in the ‘live-ball’ era. Balls are replaced routinely. Spitballs, shine balls, mud balls, emery balls, and cut balls are illegal. The reason for this is that dead or manipulated balls are no longer smooth or truly round; therefore, they fly through the air with an unpredictable trajectory.
When a ball is thrown, it rotates while in the air. So long as the ball is essentially the same everywhere on its surface, with the center of mass being at the center of the ball, the rotation is symmetrical and the ball flies straight and true. As soon as you change the surface, you change two aspects of the ball. First, you change the airflow over the ball, or friction. Second, if you change the outside enough, the ball is no longer round, and the center of mass is shifted away from the center.
Lets deal first with friction. Friction induces drag, or resistance to flow. If there is more drag on one part of the ball, caused by say, roughing up the surface, then it is not going to slide through the air as easily at that point. Air slides easily past all the other points, and the rough bit actually starts to be slowed down relative to the rest of the ball. The result is that a rotation is going to be caused at that point. Hence, the trajectory of the ball will eventually begin to curve.
Shifting the center of mass causes a similar problem. If you have ever tried to spin a top, you know that if you keep the handle or center bit straight and true, and in the center of the top, the top spins cleanly. As soon as you move the handle to one side, you’ve got wobble. Out-of-round baseballs with a shifted center of mass will wobble during the pitch in much the same way.
Of course, really good pitchers can pitch the dry spitter; legal because nothing is being added to the surface of the ball, so- named because they behave like spitballs. Knuckleballs and split-balls fall into this category. By controlling the release of the ball, the pitcher can control the spin of the ball and therefore the flow of air over the ball. Knuckleballs don’t spin as much, or at all, compared with fastballs. This makes them slow. Without spin and, importantly, without speed, the differences in airflow over the smooth parts of the ball compared with over the stitches are more pronounced. The points on the ball with stitches experience increased drag, and the ball’s trajectory eventually will tend to curve around those points. Faster pitches like the split-ball rely on basically this same principle –controlling the release of the ball so that you can impart a predictable rotation or drop onto the ball’s trajectory.
Showing posts with label baseball. Show all posts
Showing posts with label baseball. Show all posts
Thursday, April 2, 2009
Wednesday, April 1, 2009
Into the Swing of Things
A baseball is a 3-inch diameter sphere traveling at upwards of 100 miles an hour, at least in the pro leagues. It is 9 inches in circumference, and 5 ounces in weight. And, it is darn hard to make contact with it. It is in fact so hard to hit this ball that hitting it 3 out of 10 times is considered really quite good. If you were in one of my courses and got 30% correct on an exam I gave, I would ask you to seriously reconsider your career choices.
It is so hard to hit that little white ball that batting in baseball is a metaphor for life. If you push yourself to take on something really challenging you ‘step up to the plate’, if you are working really hard and aren’t giving up you ‘keep on swinging’, if you failed entirely you ‘struck out’, and if you pulled it off beautifully you ‘hit a home run’.
According to the Baseball Almanac, the best batting average in a single season, ever, is by Tip O’Neil. A 0.485. He earned this in 1887 playing for the St. Louis Browns. Of course, in 1887, they counted walks towards your batting average. But, that is not the case for several other 400 hitters on the list. In the first part of the 1900’s Ty Cobb made the list 10 times, and he is Number One on the list of all time leaders, with a lifetime average of 0.366. It is getting harder and harder to make the list, and those 400 hitters are a thing of the past. On the list of the top 100 batting averages in a single season, there are only three who played the game during years when I was alive. Ranked number 53 is George Brett of the KC Royals with a 0.390 earned in 1980. Rod Carew of the Twins batted a 0.388 in 1977, giving him the 61st spot. And Larry Walker of the Rockies batted a 0.379 in 1999, earning him the 94th spot. If you look at any of these sorts of lists, you’ll see the batting averages steadily trending downwards over time.
What is interesting, from a physics standpoint, is that those 400 scores were achieved during what was known as the dead-ball era. This is an era in baseball where the balls themselves were rarely replaced during the game, and thus they literally wore out and died over the course of the game. The dead-ball behaved unpredictably – it was not firm or smooth anymore, and therefore its trajectory was atypical. And, of course, this was hastened along during the game by the pitcher’s liberal application of spit, grease, sand-paper, and emery boards, all of which are now illegal. It seems odd that the batting averages should be higher during a time when hitting the ball was arguably harder.
It has been suggested that the live-ball baseball (where the balls are replaced at the first sign of wear) favors the hitter. Therefore, many a baseball analyst has tried to explain why batting averages have not increased over time. Enter the science of statistics and the laws of probability, another love of the science-y types. Explanations range from new pitching styles that don’t favor putting runners on the bases, to hitters that favor hitting home runs and new parks that don’t favor homeruns by design. More night games make it harder to see and hit the ball, and more relief players give batters less familiarity with individual pitching styles and reduce the chance of a hit. There has also, arguably, been an overall increase in the skill of all baseball players over time. This means that a great batter is far more likely to encounter a great pitcher, and therefore success at bat is likely to be lower than for great batter in the past. In the past great batters were rare, but great pitchers were even rarer. These all seem to contribute to a trend of increasing strike-outs or walks, and less hits relative to at-bats.
And so, they keep on swinging.
It is so hard to hit that little white ball that batting in baseball is a metaphor for life. If you push yourself to take on something really challenging you ‘step up to the plate’, if you are working really hard and aren’t giving up you ‘keep on swinging’, if you failed entirely you ‘struck out’, and if you pulled it off beautifully you ‘hit a home run’.
According to the Baseball Almanac, the best batting average in a single season, ever, is by Tip O’Neil. A 0.485. He earned this in 1887 playing for the St. Louis Browns. Of course, in 1887, they counted walks towards your batting average. But, that is not the case for several other 400 hitters on the list. In the first part of the 1900’s Ty Cobb made the list 10 times, and he is Number One on the list of all time leaders, with a lifetime average of 0.366. It is getting harder and harder to make the list, and those 400 hitters are a thing of the past. On the list of the top 100 batting averages in a single season, there are only three who played the game during years when I was alive. Ranked number 53 is George Brett of the KC Royals with a 0.390 earned in 1980. Rod Carew of the Twins batted a 0.388 in 1977, giving him the 61st spot. And Larry Walker of the Rockies batted a 0.379 in 1999, earning him the 94th spot. If you look at any of these sorts of lists, you’ll see the batting averages steadily trending downwards over time.
What is interesting, from a physics standpoint, is that those 400 scores were achieved during what was known as the dead-ball era. This is an era in baseball where the balls themselves were rarely replaced during the game, and thus they literally wore out and died over the course of the game. The dead-ball behaved unpredictably – it was not firm or smooth anymore, and therefore its trajectory was atypical. And, of course, this was hastened along during the game by the pitcher’s liberal application of spit, grease, sand-paper, and emery boards, all of which are now illegal. It seems odd that the batting averages should be higher during a time when hitting the ball was arguably harder.
It has been suggested that the live-ball baseball (where the balls are replaced at the first sign of wear) favors the hitter. Therefore, many a baseball analyst has tried to explain why batting averages have not increased over time. Enter the science of statistics and the laws of probability, another love of the science-y types. Explanations range from new pitching styles that don’t favor putting runners on the bases, to hitters that favor hitting home runs and new parks that don’t favor homeruns by design. More night games make it harder to see and hit the ball, and more relief players give batters less familiarity with individual pitching styles and reduce the chance of a hit. There has also, arguably, been an overall increase in the skill of all baseball players over time. This means that a great batter is far more likely to encounter a great pitcher, and therefore success at bat is likely to be lower than for great batter in the past. In the past great batters were rare, but great pitchers were even rarer. These all seem to contribute to a trend of increasing strike-outs or walks, and less hits relative to at-bats.
And so, they keep on swinging.
Thursday, March 5, 2009
The Science of Baseball
Ah, it is nearly Spring, and springtime means baseball! The pros are at their spring training camps in the warmer parts of the United States like Florida and Arizona. And, 300+ youths in our fair city are at Los Arboles and Preston parks swinging away with at least as much enthusiasm if not more.
Scientists love baseball. I cannot explain exactly why this is. But, this is a sport that unites geeks and jocks from coast to coast. And, in fact, the President of our city's Pony Baseball and Softball league is a geek-jock himself, scientist by day, baseball empresario by night, weekend, and most school holidays from December to July (that’d be Mr. Dr. SwimsWithFishes again).
Perhaps this is because baseball, unlike life, conforms so well to the laws of physics, where things are predictable, orderly, and behave utterly sensibly. Now, this does not mean baseball players and umpires behave so sensibly. But, ball, interacting with bat, behaves quite predictably. You can calculate, quite reliably, exactly how to hit a ball so that you will get a home run every time at bat. You can draw it on paper; determine forces, angles, and trajectories; form and solve the equations.
The sport comes in figuring out how to get a pitcher to pitch that ball to you, and how to get your body to hit that ball, just like on paper. It is the interaction between the players, and trying to figure out how to achieve a known outcome, that drives our passion for the sport. This interaction is like a dance. Even as spectators, we watch the dance with the same anxiety and emotion, fear and adrenaline as we felt back in the age of innocence at our first school dance and the boy/girl of our dreams was watching us from across the room (and all we hoped for then was that we might get to ‘first base’ with Dream Boy/Girl).
The science of a baseball home run is all in the angles. Line drives, that travel with no arc, no change in height off the ground as they leave the bat, are darn fast, but they don’t travel far. This is because of our old constant friend, gravity. The ball leaves the bat with some inertia, or some force, imparted by the swing of the bat. The magnitude of that inertial force depends on how hard the bat hits the ball. Harder hits impart greater velocities and therefore greater inertia. But, the ball is experiencing friction as it travels through the air. As it slows, eventually the force of gravity, pulling the ball down, will be larger than the inertial force and the ball will begin to fall.
Now imagine the ball is hit with the same speed but with a slight upward arc. At the time when inertial forces begin to weaken, and gravitational forces start to take over, the ball will be higher in the sky. The increased distance to the ground, and the trajectory of the arc, ensure that the ball travels farther before actually contacting the ground. Intuitively, we know this. Line drives rarely hit the home run fence. Home runs are big arcing hits that soar into the grandstands.
It is actually more difficult to hit a ball fast with an upward trajectory than with a straight one. Line drives are fast and pitchers hit with these balls get hurt, badly. However, even if the force imparted onto the ball is lower, a sufficient arc will take the ball farther. A little arc goes a long way, and you can get too much of a good thing. Obviously, a ball hit straight up goes nowhere at all except up. The science is in finding the just right arc. In baseball, as in life.
Scientists love baseball. I cannot explain exactly why this is. But, this is a sport that unites geeks and jocks from coast to coast. And, in fact, the President of our city's Pony Baseball and Softball league is a geek-jock himself, scientist by day, baseball empresario by night, weekend, and most school holidays from December to July (that’d be Mr. Dr. SwimsWithFishes again).
Perhaps this is because baseball, unlike life, conforms so well to the laws of physics, where things are predictable, orderly, and behave utterly sensibly. Now, this does not mean baseball players and umpires behave so sensibly. But, ball, interacting with bat, behaves quite predictably. You can calculate, quite reliably, exactly how to hit a ball so that you will get a home run every time at bat. You can draw it on paper; determine forces, angles, and trajectories; form and solve the equations.
The sport comes in figuring out how to get a pitcher to pitch that ball to you, and how to get your body to hit that ball, just like on paper. It is the interaction between the players, and trying to figure out how to achieve a known outcome, that drives our passion for the sport. This interaction is like a dance. Even as spectators, we watch the dance with the same anxiety and emotion, fear and adrenaline as we felt back in the age of innocence at our first school dance and the boy/girl of our dreams was watching us from across the room (and all we hoped for then was that we might get to ‘first base’ with Dream Boy/Girl).
The science of a baseball home run is all in the angles. Line drives, that travel with no arc, no change in height off the ground as they leave the bat, are darn fast, but they don’t travel far. This is because of our old constant friend, gravity. The ball leaves the bat with some inertia, or some force, imparted by the swing of the bat. The magnitude of that inertial force depends on how hard the bat hits the ball. Harder hits impart greater velocities and therefore greater inertia. But, the ball is experiencing friction as it travels through the air. As it slows, eventually the force of gravity, pulling the ball down, will be larger than the inertial force and the ball will begin to fall.
Now imagine the ball is hit with the same speed but with a slight upward arc. At the time when inertial forces begin to weaken, and gravitational forces start to take over, the ball will be higher in the sky. The increased distance to the ground, and the trajectory of the arc, ensure that the ball travels farther before actually contacting the ground. Intuitively, we know this. Line drives rarely hit the home run fence. Home runs are big arcing hits that soar into the grandstands.
It is actually more difficult to hit a ball fast with an upward trajectory than with a straight one. Line drives are fast and pitchers hit with these balls get hurt, badly. However, even if the force imparted onto the ball is lower, a sufficient arc will take the ball farther. A little arc goes a long way, and you can get too much of a good thing. Obviously, a ball hit straight up goes nowhere at all except up. The science is in finding the just right arc. In baseball, as in life.
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