Calculating BaseRuns Custom LWTS

[skyking162]

Any tips from the database pros about calculating a bunch of sets of BaseRuns custom linear weights all at once? Not sure what sorts of queries/calculations would automate the process. Thanks.

[Tango Tiger]

Patriot has it all laid out on his site.

[Patriot]

Any tips from the database pros about calculating a bunch of sets of BaseRuns custom linear weights all at once? Not sure what sorts of queries/calculations would automate the process. Thanks.

Can't help you with database queries, but the LW of any event is equal to:

LW = ((B + C)(Ab + Ba) - AB(b + c))/(B + C)^2 + d

Where A, B, C, and D are the total A, B, C, and D factors for the entity in question. So if you are doing the 1990 NL and there were 1800 home runs hit in that league, D = 1800.

a, b, c, and d are the coefficient for the event in question in the A, B, C, or D factor. For example, a home run has a = 0, b = ~2 (or whatever coefficient the HR has in your B factor), c = 0, and d = 1.

[skyking162]

Can't help you with database queries, but the LW of any event is equal to:

LW = ((B + C)(Ab + Ba) - AB(b + c))/(B + C)^2 + d

Where A, B, C, and D are the total A, B, C, and D factors for the entity in question. So if you are doing the 1990 NL and there were 1800 home runs hit in that league, D = 1800.

a, b, c, and d are the coefficient for the event in question in the A, B, C, or D factor. For example, a home run has a = 0, b = ~2 (or whatever coefficient the HR has in your B factor), c = 0, and d = 1.

That's exactly the sort of trick I was looking for. Thanks, Patriot!

Your equation contains no big D -- is that correct?

[Patriot]

Yeah, no big D, since Base Runs sets aside the run-scoring home run as one run. The advancement portion of the home run is incorporated in the B factor and that is where home runs have the opportunity to interact with the other events and change their values. I probably shouldn't have used a big D example.

BTW, that formula is the precise Linear Weight value...the "+1" approach will come very close to it though. The formula is really doing the +"infinitesimal value" approach that the defines the derivative in calculus.

[skyking162]

The formula is really doing the +"infinitesimal value" approach that the defines the derivative in calculus.

When I go back to teaching, this will be example number one of why calculus is cool and useful.

[Tango Tiger]

Here's Patriot work on the matter (go to near the bottom):
http://gosu02.tripod.com/id108.html

And he points to some of the Calculus work here:
http://members.cox.net/~harlowk22/br1.html

[digglahhh]

When I go back to teaching, this will be example number one of why calculus is cool and useful.

The coolest thing I ever saw a teacher do involving math (when I was in high school) was come up with an equation off the top of his head that would graph the Nike swoosh on a graphing calculator. His first try was pretty close, and then he tweaked it and got it pretty good, I must say.

Of course sabermetrics is much cooler on a practical level.