K/PA

[Crash2303]

wondering if there's any merit to this. For pitchers, there's K/9 to judge strikeout proficiency, but wouldn't a more valuable statistic be K/PA? this would track the frequency of strikeouts as opposed to the total. For instance:

Pitcher A strikes out 3 in 3 innings for a 9.0 K/9, but faces 18 batters for a .166 K/PA

Pitcher B strikes out 3 in 3 innings for a 9/0 K/9, but faces 9 batters for a .333 K/PA

 

Pitcher B is by far the more proficient strikeout pitcher, but in a traditional K/9, they both have the same value. What essentially we want to know is not how many they get per inning, but what percentage of guys do they strike out.

 

Is this already a stat somewhere, and if so- how commonly is it utilized?

[1992casey]

We've had this discussion before, and you're right. However, the caveat that one of our stat gurus explained a few years ago is that K/AB is more appropriate than K/PA. I can't split that hair and explain why. But either K/PA or K/AB would be better than K/9.

 

Essentially, a poor pitcher can have the same K/9 as a good one. The lousy one achieves his K/9 by facing more hitters, and the good one is penalized for not giving up hits and walks.

 

I'd submit that we use K/9 because it's conveniently offered by websites and because it paints an easy mental picture. Six Ks in nine innings is easy to picture. Numbers like .166 aren't. What would be great is an adjusted K/9, which would actually be K/AB multiplied by the average number of ABs in a game. That would make it look like K/9 and eliminate the learning curve that would come with understanding the number.

[Crash2303]

thanks casey- really helpful to know. sounds like ripe ground for a new stat- go for it!

[SRB]

K/PA is available on Fangraphs as K% (and possibly under the advanced metrics on Baseball-Reference now as well?).

[JohnBriggs12]

All I know is Brewers have several players with very high K/PA rates: Broxton, Santana, Carter to name just a few.

[Jenkins5]

All those guys have high BB/PA as well

 

When I look at Ks I care most about percentage over K/9. If I'm targeting a pitcher, I prefer them to be around 25%+ K/AB.

[Oxy]

While using K/PA would be a better measure to determine the past efficacy and dominance of a pitcher, there is some value in using K/9 as well when determining how good a pitcher's pure "stuff" is, and how good he can potentially be if he could just get some better command of his pitches. A young Randy Johnson or Nolan Ryan might have the same K/PA as a Derek Lowe or Jamie Moyer, and might have even poorer FIP, WHIP and ERAs, which if just looking at the numbers one would/could conclude that those Johnson and Ryan guys stink. However, their through-the-roof K/9 stat might show you that they have something special hidden behind the control issues.

[jdw42434]

K/PA is a better measure. But in life, and especially baseball, people tend to stick to "the way things have been done before". So K/9 will remain the preferred statistic.

 

I'm not so sure, as others have claimed, that K/9 is easier to interpret. Sure people can have difficulty with proportions (decimals), but if you make K/PA a percentage then I think it is at least as easily understood as K/9.

- 10 strikeouts per 9 innings

- vs 30% strikeout percentage.

 

 

Another overly used statistic are innings limits. Not all innings are equal! You can have a 3 pitch inning (+ warmups), or a 30+ pitch inning. Pitch counts are a better measure, but even then, I would rather have my pitcher (for his arm's sake) give me six 10 pitch innings than two 30 pitch innings or three 20 pitch innings.

[1992casey]

30% strikeout percentage

 

If I saw that stat without being familiar with it, my first question would be "percentage of what?"

 

I think teams are aware that not all innings and pitch limits are created equal. And I think most people who post here are aware of that too. It's just that we don't always bother to make that clarification every time we post.