BPV formula -- PLEASE HELP!

[ackermaj]

I am trying to use the BPV formula from the glossary to calculate past year's BPVs for pitchers.

The formula as stated is:

(Dominance Rate x 6) + (Command Ratio x 21) - (Opposition HR Rate x 30) - ((Opposition Batting Average - .275) x 200

But when I plug in the numbers, the BPV I come up with does not equal the BPV on Playerlink. (I was doing a test to make sure my formula was right, and wanted to match it up against the 'Actual to date' BPV in PLayerlink for accuracy.)

Can anyone shed some light on what I might be doing wrong?

My formula in Excel is as follows (where A5 - D5 correspond to the formula above):

=SUM(A5*6)+(B5*21)-(C5*30)-((D5-0.275)*200)

[PD@HQ]

I can't vouc for the formula but I'm not sure about the use of the SUM command in this formula. What hapens if you remove SUM and just use =(the terms)?

[Neil@HQ]

From my Excel file that I use to prepare the tables for my weekly Market Watches:

=SUM(K6*6)+(L6*21)-(M6*30)-((I6-0.275)*200)

which is the same as you use for your formulas. Make sure you use this formula to calculate the Opposition Batting Average:

=SUM(C6)/((B6*2.82)+C6)

Which is: (Hits)/((IP*2.82)+Hits)

Does that help?

[ackermaj]

Neil,

Thanks a lot for the help. That does make a difference, but my result still isn't exact.

My test case is Randy Johnson, actual year to date BPV.

Using the OBA on Playerlink (.230), I get a BPV of 187.2

Using the method you suggest of calculating OBA (which gives me an OBA of .194), I get a BPV of 194.

Playerlink lists his year to date BPV as 201.

Not a huge difference, but I'm just curious what I'm missing. Maybe you can plug his numbers in your sheet and see what you get?

[Neil@HQ]

I get 194 BPV as well. On PlayerLink the program may be doing some rounding where Excel is calculating it very accurately. I'll bring the issue up to the data guys and see what they say about it.

You are doing everything "correctly" as far as the calculations go.

-Neil

[ackermaj]

Thanks again for the follow-up, Neil.

Jeff

[BlaineFred]

Hello HQ...

Questions on the BPV's...

As I see it, the leagues and park factors are not taken into consideration, except perhaps indirectly.

That is, pitchers in hitter-friendly leagues like the PCL or Texas League are likely to have lower BPV's than pitchers in the Eastern League or the Florida State League that are tougher on hitters.

Is there some way to account for the league differences when comparing the BPV's of various pitchers?

Second question...from looking ar BPV's over the years, I have seen that relievers tend to have much higher BPV's...especially those who don't pitch a lot of innings. And since the innings are much fewer, the data sample is lower, leading to more inaccurate or unreliable results. Is this an accurate assessment, or not?

Tnx,

Roland