An interesting point.

However, I very much doubt that the majority of people actually 'see'/comprehend the difference between an ERA of 3.8 and an ERA of 3.9 (which are obviously both measured in terms of 9 innings) whilst watching a game, - if you propose to measure HR's in terms of 1.2, 1.3, etc. per 9 innings, it will simply be a case of people becoming familiar with the format, and thus 'recognising' the difference in value between the two. Most pitchers do not pitch a complete game in the majority of their outings, yet we are still able to comprehend the differences in ERAs.

So a person can know that an ERA of 3.45 is better than an ERA of 3.95 without actually visualising that extra half half a run per nine innings - similarly, if used consistently, a viewer will realise the difference between 1.25 HR and 1.35 HR allowed per 9 innings, without actually visualing the 0.10 HR difference.

This is, however, simply in terms of the observational fan - in terms of stats collection/season to season comparison, the idea of measuring it per 200 could indeed work very well - it is simply a matter of the method of calculation registering and becoming familiar with 'Joe Public', so that a 'rating', if you will, can be applied subconsciously to the number itself.

I like it. You're right, it's much easier to grasp the #s that way

Actually, I'd prefer if we evaluated pitchers in terms of opponent's OBP and opponent's SLG. Of course, opponent's OPS follows from there.

Fundamentally, it appears to me that the game of baseball is offense versus defense (or more simplistically hitter vs pitcher). Just like basketball offense/defense might be measured by FG% and opponent's FG%, a few simple stats (like OBP, SLG, OPS) give easy comparison to the mean. Thus, even a caveman can tell whether the player/pitcher is above or below the mean.

(Of course, this is a little more complicated because the baseline for hitters depends on what position they play in the field and the baseline for pitchers depends on their role).

Still, measuring pitchers relative to opponent's OBP, SLG, OPS seems underutilized.

What about making all those rates into 10 innings.

Metric system is my friend in engineering and is a whole lot better than all the stupid English units.

Think about it... thinking in terms of 10's is the most simple way to think about numbers. It'll make it easier for new fans to understand, and fan's won't leave because of it. It's easy to just apply a constant to make any number in base 10s.

I prefer the OBP/SLG against as well. If a pitcher had a 0.6 HR/9 and his SLG against was .354 ... they both say the same thing... Hitters aren't hitting for very much power against him.

It's pretty easy to see a terrible pitcher by their AVG/OBP/SLG allowed... they often look like fantastic seasons for hitters. Picking out great pitchers is just as simple.

.343/.384/.590 = Josh Towers 2006
.205/.248/.288 = Pedro Martinez 1999

As an evaluation stat, HR/FB, LD%, GB%, and FB% are a bit more intuitive for me. You can actually infer information about their 'stuff' from those numbers.

I kind of like the HR/9. I know that ground ball pitchers can get it down to around .7, fly ball pitchers are often around 1.3, and 1.0 is a good approximation of "average" (for a MLB regular rotation guy). I see your point, I'm just not sure 200 innings gives a number that can be more easily understood.

The beauty of the /9 numbers is that they give you an approximation of what an average start is like (overestimating, of course). It's always surprising to know that even the good pitchers like Beckett will, on average, give up a HR every start they have.

The problem with the BA/OBA/Slug line is that you have the defense involved. K/9 BB/9 HR/9 involve outcomes that are only between pitcher and batter.

I think we should measure HR per batter faced if we really want to get technical. Why do we measure per inning/game when neither of those is a fixed length batter-wise?

For instance, two pitchers have a HR/9 of 1.0. Pitcher #1 is 2000 Pedro Martinez (WHIP of .737), Pitcher #2 is 2000 Jamie Moyer (WHIP of 1.468). Over 9 innings, you'd expect Moyer to give up 13 runners or so. Assuming no double plays, that means 40 batters/game. Pedro, on the other hand, would give up less than 7 runners per game, meaning 34 batters per 9.

Over a season of 180 innings, both would give up 20 HR. However, Moyer would be more stingy, giving up a HR every 40 batters, to Pedro's HR every 34 batters.

I like the HR/200 idea.

In general, I think the "stats" community would do better if they tried to design statistics that were not only descriptively useful but also intuitive to people who just watch the game. Stuff like how EqA is standardized along lines similar to common understandings of BA (.300 is pretty good, .270 is okay, .330 is awesome).

I'm with Hazey and Sal Paradise.

Hazey is right that the scale of measurement is largely irrelevant, as people will "learn" to read whatever scale is used. Additionally, I think it's beneficial to keep every stat on the same scale - such as per nine innings - so that people don't have to mentally "juggle" their expectations each time they try to read a stat.

If you're going to change the scale, though - and from my last sentence, I would suggest it be done for all the stats - then Sal Paradise is right that it should move to per batter faced. What use is a per nine or even a per 200 inning stat of a reliever that will never pitch more than two innings at a time or 80 innings in a season? Per batter faced is the only scale that we can guarantee will be applicable for every pitcher.

I think homers per nine innings is just fine, although it should be carried to two decimal places, not just one.

It would seem the translation to homers per 200 innings would be pretty simple, given that 200 innings is about 22 nine-inning games, meaning that a 1.00 homer per nine inning rate would be about 22 homers per year if the pitcher indeed pitches 200 innings.

Patrick Misch has yielded something like 10 homers in about 32 innings. That's something around 2.8 per nine innings, which looks bad enough. If we converted to homers per 200 innings, poor Patrick would be at about 63, which I believe would place him just ahead of Roger Maris.

I think homers per nine innings is just fine, although it should be carried to two decimal places, not just one.

It would seem the translation to homers per 200 innings would be pretty simple, given that 200 innings is about 22 nine-inning games, meaning that a 1.00 homer per nine inning rate would be about 22 homers per year if the pitcher indeed pitches 200 innings.

Patrick Misch has yielded something like 10 homers in about 32 innings. That's something around 2.8 per nine innings, which looks bad enough. If we converted to homers per 200 innings, poor Patrick would be at about 63, which I believe would place him just ahead of Roger Maris.

I think homers per nine innings is just fine, although it should be carried to two decimal places, not just one.

It would seem the translation to homers per 200 innings would be pretty simple, given that 200 innings is about 22 nine-inning games, meaning that a 1.00 homer per nine inning rate would be about 22 homers per year if the pitcher indeed pitches 200 innings.

Patrick Misch has yielded something like 10 homers in about 32 innings. That's something around 2.8 per nine innings, which looks bad enough. If we converted to homers per 200 innings, poor Patrick would be at about 63, which I believe would place him just ahead of Roger Maris.

I think homers per nine innings is just fine, although it should be carried to two decimal places, not just one.

It would seem the translation to homers per 200 innings would be pretty simple, given that 200 innings is about 22 nine-inning games, meaning that a 1.00 homer per nine inning rate would be about 22 homers per year if the pitcher indeed pitches 200 innings.

Patrick Misch has yielded something like 10 homers in about 32 innings. That's something around 2.8 per nine innings, which looks bad enough. If we converted to homers per 200 innings, poor Patrick would be at about 63, which I believe would place him just ahead of Roger Maris.

I think homers per nine innings is just fine, although it should be carried to two decimal places, not just one.

It would seem the translation to homers per 200 innings would be pretty simple, given that 200 innings is about 22 nine-inning games, meaning that a 1.00 homer per nine inning rate would be about 22 homers per year if the pitcher indeed pitches 200 innings.

Patrick Misch has yielded something like 10 homers in about 32 innings. That's something around 2.8 per nine innings, which looks bad enough. If we converted to homers per 200 innings, poor Patrick would be at about 63, which I believe would place him just ahead of Roger Maris.

HR/IP