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What Happens When Baseball-Stats Nerds Run a Pro Team

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Re: What Happens When Baseball-Stats Nerds Run a Pro Team

#51

Post by thaumasiotes »

kriro wrote: post #42
cortesoft wrote: post #10

Earlier quoted context omitted.

Yes, there is a lot of luck. For one thing, the gap between very bad players and very good players is fairly small in an absolute sense; for example, a player who gets a hit 25% of the time would have trouble staying in the league, but a player who gets a hit 30% of the time has a good chance of being an all-star. A 5% increase in your success rate separates the very worst players from the very best. There is a great…

Isn't a 20% skill difference pretty meaningful in most endeavors? Maybe not the difference between unemployment and rock star but being 20% better at sales for example can be quite lucrative.

Your 20% is a relative difference, not an absolute difference.

The difference between hitting 0.5% of pitches and 0.6% of pitches isn't meaningful at all despite being the same relative difference.

Re: What Happens When Baseball-Stats Nerds Run a Pro Team

#53

Post by mathattack »

allisthemoist wrote: post #27
mathattack wrote: post #4

I like that this captures something very important about Data Science. The data may give the truth, but it's the story that makes people change. The story taps our emotions, which cause us to change behavior faster than hard data. The chief analyst at a prior employer once commented that he liked people "with degrees that suggest storytelling" in addition to their math/science/engineering pedigrees.

Because what is a story really but condensed data?

The story taps emotions, and impacts decisions better than just raw data. This is why politicians try to attach names and faces to policies. Good leaders use the data to inform the decisions, but stories to explain them.

Re: What Happens When Baseball-Stats Nerds Run a Pro Team

#54

Post by kriro »

thaumasiotes wrote: post #51
kriro wrote: post #42

Earlier quoted context omitted.

Isn't a 20% skill difference pretty meaningful in most endeavors? Maybe not the difference between unemployment and rock star but being 20% better at sales for example can be quite lucrative.

Your 20% is a relative difference, not an absolute difference. The difference between hitting 0.5% of pitches and 0.6% of pitches isn't meaningful at all despite being the same relative difference.

The league wide batting average in the MLB was .253 in 2013 (first Google result, I'm assuming it doesn't vary all that much between seasons). While you are correct that hitting 0.6% compared to 0.5% doesn't mean much the numbers I responded to were meaningful in an MLB context (.250 vs. .300) so I think it's justified to use relative differences. In fact I think it's more insightful than using absolute numbers. Speaking of a 5% increase in that context is confusing (at least to me :D) when in reality the skill is roughly 20% above league average. A programmer who is 20% above average will certainly command a premium as will a salesperson.

Re: What Happens When Baseball-Stats Nerds Run a Pro Team

#55

Post by thaumasiotes »

kriro wrote: post #54
thaumasiotes wrote: post #51

Earlier quoted context omitted.

Your 20% is a relative difference, not an absolute difference. The difference between hitting 0.5% of pitches and 0.6% of pitches isn't meaningful at all despite being the same relative difference.

The league wide batting average in the MLB was .253 in 2013 (first Google result, I'm assuming it doesn't vary all that much between seasons). While you are correct that hitting 0.6% compared to 0.5% doesn't mean much the numbers I responded to were meaningful in an MLB context (.250 vs. .300) so I think it's justified to use relative differences. In fact I think it's more insightful than using absolute numbers. Spea…

As I understand it, a baseball player who performs at the average level is already close to being a superstar; most players are below. This is the reason baseball statistics assess players in terms of "wins above replacement" rather than comparison to the average -- it would be very difficult, if you fired a player, to get an average player to fill your vacancy. (You may wonder how this could be, if baseball ability is normally distributed. Baseball ability is normally distributed in the general population, but not among professional baseball players.)

The comment you responded to was making the point that it's massively unrealistic to expect a team to have a win rate too far from 50% because the absolute difference in skill among all players is small (which means that the skill differences are easily overcome by random variation). Relative differences between players aren't relevant to that argument; you'd need to be talking about the relative difference between the size of the absolute skill gap and the effect of day-to-day variation.

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