Comments on: The Call Up: Freddy Peralta

By: Nicholas Zettel

Nicholas Zettel — Thu, 17 May 2018 15:33:20 +0000

Instead of calculating it this way, you can use the Baseball – Reference Three Year factor, or the Baseball Prospectus Pitching Park Factor, and simply multiply League RA9 * (park factor). Here’s my post on Runs Prevented (http://milwaukee.locals.baseballprospectus.com/2018/03/22/exploring-runs-prevented/). I’ll hope to have actual rankings up today.

By: Steven

Steven — Thu, 17 May 2018 14:53:05 +0000

Another question in your formula (sorry for all the q’s) you list:

PF*(R*9)/IP-(R*9)/IP

These are different R values, correct? Otherwise it is just (PF-1)*Actual RA9. This doesn’t seem to be measuring run prevention, but rather what parks the team has played in. Is the first R league average runs? Or am I missing something?

By: Steven

Steven — Thu, 17 May 2018 14:46:22 +0000

Actually, as I thought about doing this are you using the team’s park factor or the stadium’s, i.e. for the Brewers it would be (3 x Petco + 3 x Busch + 3 x Citi + 3 x GAB + 4 x Wrigley + 2 x Kaufman + 4 x Coors + 3 x Chase + 19 x Miller)/44. This seems to be the way you would have to do it. Is the specific park factor for a team easily available?

By: Steven

Steven — Thu, 17 May 2018 14:30:42 +0000

That makes a ton of sense. What I like about it is that it encompasses the entire run prevention side of the game. Frequently we get so into the weeds trying to determine if a certain individual is good, and try and tease out the other influences, but when evaluating a team’s run prevention ability it is better to look at the whole, rather than the sum of individual parts. I love it and think it should be published, but it is also easy enough that if I want to look at it I can just go calculate it quick.

By: Nicholas Zettel

Nicholas Zettel — Tue, 15 May 2018 14:12:01 +0000

Good question. I use Runs Prevented as (Expected RA9) – (Actual RA9), where “Expected RA9″ = (Baseball Reference Three Year Park Factor)*((R*9)/IP), and “Actual RA9″ = ((R*9)/IP). If this is something readers are interested to see, I would be happy to publish them on a weekly or monthly basis.

Overall, 18 Runs Prevented over ~40 games is phenomenal. That total (18) would be solid for 162 game season, and if you extrapolate it to 162 game pace, that is a league leading type pitching staff.

By: Steven

Steven — Tue, 15 May 2018 13:58:45 +0000

Where does one find the runs prevented statistic. Your article pre-season convinced me that the Brewers strategy of having 10 fine pitchers can be as effective as having 5 really good pitchers. It is interesting to note that they have been slightly worse than average, but only slightly. But actually, I don’t really know what -6 means. What is the range on that metric? Is -6 middle of the pack, with bad rotations (Reds) -30? Is the leaderboard on BP? Also, is +18 good for a pitching staff?