How to maximize "winning" under budget con
2015-05-30
Billy Beane, the main character in this book, was a overrate hot prospect, was a scout at the age of 31, but his career as general manger brings more far-reaching effect on baseball, or we could barely say, on the whole professional sports.
On the first day in the front office, Billy Beane delved the real meaning for his job: "in professional baseball it still matters less how much money you have than how well you spend it." The truly economical meaning, as he try to solve, is the measure of financial efficiency: how many dollars over the minimum $7 million does each team pay for each win over its forty-ninth? How many marginal dollars does a team spend for each marginal win?
I do remember the first time I learn game theory in advance-microeconomic class. My dear professor set a matrix between two players: pitcher and hitter. He is a fan of Detroit Tigers who was born in Colorado, while I am a new adherent of Red Sox who come from China. It doesn't matter when we discuss baseball and how the game works. On my side, I love pitcher more than other roles on the field. Pitcher is the soul, the leader inside defense, the exactly same job as center back in soccer. On Beane's side, the most important quality in a pitcher was not his brute strength but his ability to deceive, and deception took many forms. That's why we need to find the merit of defense, rather than some risk-appreciaton performance.
What we care about is winning, do defense and find a way to cost opponent. Thus we need to find good hitter, the powerful but must be good hitter, since the physical gifts required to play pro ball were, in some ways, less extraordinary than the mental ones. We need to find the way to measure good player among those pseudo-good players, trying to avoid the type II error. Scouts, who thought their own experience was typical when it wasn’t. There was also a tendency to be overly influenced by a guy’s most recent performance: what he did last was not necessarily what he would do next. We need more scientific way to measure players, judge their performance and acquire them at the lower price. That is the foundation for us to maximize "winning" under budget constraint.
Here comes sabermetrics: everything from on-field strategies to player evaluation was better conducted by scientific investigation—hypotheses tested by analysis of historical statistical baseball data—than by reference to the collective wisdom of old baseball men.
Why would the people in charge allow professional baseball to be distorted so obviously? The answer was equally obvious: they believed they could judge a player’s performance simply by watching it. Ironically when Clint Eastwood played an old scout in "Trouble with the Curve", he tried to tell us how important an experienced scout is in baseball, but the pale ending part shows us how statistics could do better than just "scout" by eye, or by feeling. They don't care about statistics, what those scouts care is how the talent looks, how he played under their sight, and his family gene. We know they use some indicators, but we know better on numbers, since those digits don't lie.
Bill James is the pioneer in sabermetrics. When he published his 1977 Baseball Abstract, two changes were about to occur that would make his questions not only more answerable but also more valuable. First came radical advances in computer technology: this dramatically reduced the cost of compiling and analyzing vast amounts of baseball data. Then came the boom in baseball players’ salaries: this dramatically raised the benefits of having such knowledge.
Old fashion way doesn't work. People cares about performance, but fans don't care about how to recruit players, what they care is winning, keep winning and never stop. For winning, a hitter should be measured by his success in that which he is trying to do, and that which he is trying to do is create runs. Good pitchers were pitchers who got outs; how they did it was beside the point.
Billy Beane find the key for his A's 19 consecutive winning : two, both offensive statistics, inextricably linked to baseball success: on-base percentage and slugging percentage. Everything else was far less important. In his model an extra point of on-base percentage was worth three times an extra point of slugging percentage. We know other managers will copy his formula, but the point is not that Billy Beane is infallible. The point is that he has seized upon a system of thought to make what is an inherently uncertain judgment, the future performance of a baseball player, a little less uncertain. He’s not a fortune-teller. He’s a card counter in a casino.
The point is not to have the highest on-base percentage, but to win games as cheaply as possible. Economically, we "win".