Calculating Z score for batting average

[Mike_nyc]

Thinking about it further, I'm guessing I should use my entire player universe, since K totals, for example, would favor SP's and bring down a good RP's strikeout value.

Is this correct?

[RugbyD]

Thinking about it further, I'm guessing I should use my entire player universe, since K totals, for example, would favor SP's and bring down a good RP's strikeout value.

Is this correct?

I would limit it to what players you think are reasonably draftable, otherwise you start comparing to guys who will only get 350 ABs and that will skew your playables too high.

[Mays]

In the end, this actually takes ABs back out the equation. xH tells us how much a players performance increases the overall team numerator when computing team BA, but not how much it increases the denominator. And you need both to know the value.

I.e. ARod has 13 hits over average. My team altogether has 60 hits over average. Some other team also has 60 hits over average. The winner is whichever team attained that in the fewest at bats. It's information you need to know.

But as a rough guide of value, it does have its purpose.

Yep, this all assumes that each team manages to compile about an equal number of AB. If there is a big variation between teams, it won't work as well.

[Mays]

this has been great info thanks alot. after calculating all the xH's, he calculates the SD of these values as part of his formula, correct?

Correct. Once you calculate xH, you have a counting stat that works just like SB or HR. So you calculate the z-score just like you would for those categories:

AVG value = player_xH / stdev(xH)
SB value = player_SB / stdev(SB)
etc.