Boy does Texas have an awful infield. They really need to trade Soriano in the offseason before people catch on that he’s not very good.

Thanks Chris and Dan for getting this posted.

If I were Texas, I’d try to move Blalock and Soriano for pitching to teams impressed by their hitting stats, play Young at 2nd, consider Teixiera as a 3B (he’s played there before, his range is good, though I don’t know about his arm).

Adrain Gonzalez takes over 1st and Ian Kinsler at short.

CHONE!!

In the field he’s Jorge Cannot.
The year before he figured out how to hit, I called him Jorge Can’tDo.

I like that you’re not trying to claim the superiority of this metric, but I’d like more reasoning as to why you’d advocate using this over one of the zillion other methods of evaluating defense (say, FR). You may also want to get into more of the detail of the limitations of your measure.

In regards to Cliff Floyd…

He looked much improved in LF this year by pure observation (and I think most of the Met fans around here would agree with me) and I would say he was above average this year, though best LF is pushing it a lot.

Well you’ve got Kevin Millar at -1.  Most systems seem to think his ability to cut off the 2B (while often not making outs) makes him a good defender at 1B.

On the basis of that, I’ll call it a success.

Although it’s not obvious to me why that would be the case given the inputs are mostly the same, no?

Kelly Johnson was a pretty crummy left fielder. As DSG’s defensive ratings loved him too, he must have gotten really lucky and had a lot of balls hit right at him to “game” these systems. I assume the run values are “raw” as opposed to per 150?

Very nice work, “Chone.”

On a team level (using DER converted into runs), this method correlates with an r of .60

I’m not really sure if that’s better or worse than other methods.  I’m not advocating using this over anything else.  I would suggest using different methods to complement each other, as long as they have some degree of accurracy at a team level.

Something like FR (I’m assuming you mean the one from Hidden game of baseball over 20 years ago) doesn’t hold up on a team level.

Interesting stuff Chris.  How do you calculate average zone rating?  Are you multiplying Total Chances times ZR for each player and summing that, then dividing by league total chances?

SG, that’s exactly right. 

I’m the author, I chose to go with Chone as a pen name since there is another Sean Smith and Angel fan who has posted here.

Was that play legal? Isn’t it foul if the player winds up in the stands?

Defintion of a catch:

A fielder may reach over a fence, railing, rope or other line of demarcation to make a catch. He may jump on top of a railing, or canvas that may be in foul ground.

Rule 7.04(c) states:

If the fielder or catcher, after having made a legal catch, should fall into a stand or among spectators or into the dugout after making a legal catch, or fall while in the dugout after making a legal catch, the ball is dead and runners advance one base without liability to be put out.

Rule 7.04(c) makes no distinction as to whether the ball is fair or foul, and indeed the reference to the dugout in the rule suggests that no distinction was intended.

It seems to me that the interpretation of the rule should be this:

1. If Uribe didn’t make the catch before falling into the stands, it wasn’t a legal catch - the rule says that a fielder may *reach over* the fence to make a catch, not that he can *go into* the stands to make a catch.

2. If Uribe did make the catch before falling into the stands, then once he fell into the stands the ball should have been declared dead and the runners advanced one base.

—MWE

Crap, sorry ARoM, this seemed like a Dial type article.  Good work anyway.

No prob, it is a Dial type article, Chris has something along the same lines in the works.

In this system, I use 1.00 as the run value of an outfield assist.  Chris thought it should be 0.75, the same as any other assist.

My opinion is that an average OF assist has to be worth more, as it is more likely to happen at 3rd or home than an infield assist.

I looked at the run value of Guerrero’s 2004 assists using retrosheet and before and after run expectancy, and the average run value of his 13 assists that year was 0.84

That’s a small sample, but I’m not sure how to go about finding the average value of OF assists.  With Ray Kerby’s ASS, I was able to see assists broken down by what runners were on base, but not the number of outs or where the assist went. (With runners on 1st and second and a single is hit, I don’t know if they get the runner at the plate or the batter advancing to second)

Anyone know of a study on OF assists?

I’m not really sure if that’s better or worse than other methods. I’m not advocating using this over anything else.

Your data has an R=0.8 with the data MGL posted.  That’s pretty strong.

I will have a full list for my GG article (you, MGL, Grassko, maybe BPro).

Also, DPs is problematic because they are a “team” play.  A bad SS can completely screw over a 2B.  After a decade of work, Defensive Average, MGL and I came to the conclusion (independently) there isn’t enough difference to indicate much. 

You give half credit, but I think the problem is the number of DPs started by the 3B, where the 2B takes them all.  To sum up - you have far too much weight on DP runs.

One of the GREAT (and there are many graet things) about the Hardball Times book is DPs started.  That’s a great stat that could be investigated more.

That figure includes a park factor for Manny, the only park factor used in these ratings. He’s at –32 without it.

I have a WAG that there may be a park factor for Floyd at Shea.

My opinion is that an average OF assist has to be worth more, as it is more likely to happen at 3rd or home than an infield assist.

Not that much more likely, actually.

I haven’t looked at recent data, but the last time I looked a couple of years ago, I found that most OF assists actually occur at 2B. The major plays here are (1) runners trying to stretch singles into doubles; (2) runners trying to advance on the back end of plays at 3B or home being thrown out; and (3) the occasional force plays on shallow pops to the OF.

—MWE

Also, DPs is problematic because they are a “team” play. A bad SS can completely screw over a 2B.

And vice versa. It’s more likely to be a problem with the 2B because (a) his job as the pivot man is harder and (b) he’s usually in the middle of more of them because there are more GBs hit to the left side.

—MWE

I have a WAG that there may be a park factor for Floyd at Shea.

What would be causing that?

I have a silly question about ZR vs UZR. At what point does increasingly granular information start to become too noisy and random, and actually start to make the ratings worse, rather than better? Or is there no such point?

What would be causing that?

I’m not a stat guy Chris, which is one reason it is little but a WAG. However, I have always sorta kinda thunk that Shea was a bad LF HR park, <u>i.e.</u>, there are more fly balls to be caught out there. If true, it could be the wind pattern for all I know. I also think the Mets were very tough at home against right handed hitters but I have no idea how to allocate that b/w pitching (e.g., Pedro) and defense.

I’m very much not a statitician, but ...
several years ago, Sagarin argued that more computer rankings needed to be added to the BCS calculation even if that devalued the Sagarin Ratings.  More systems took care of bumps in the data—Chone’s Floyd for instance.

So what I’d like to see is a BCS type of ranking of defense.  Take every defensive calculation out there, rank everybody 1-30 (maybe separate rankings for the non-primary fielders), remove the best and worst for each player, and add them up. [And maybe a version on the side where each position is scaled rather than rotisserie ranked.] That’s EVERY defensive system all y’all can get your hands on,[Fielding .pct; FR; ZR, UZR; Davenport’s; Chone’s; Strat; DMB; ZiPs; and apologies for those I’ve missed] with encouragement for more statheads to join the play.

Of course, I want someone else to run the rankings.

Jeremy’s right. For the second year in a row, Cliff definitely looked above average, but I would have never guessed the best in LF.

When healthy, the Mets’ defense in the outfield was pretty slick in 2005.

Chris,

It’s GASSKO. No “r”.

Anyways, nice article Sean. A few comments:

1. For double plays, you must include an estimate of runners on second. Otherwise a team with a lot of doubles or to a lesser extent, steals, allowed is going to look worse.

2. Is a DP really worth .75 runs more than a regular out? I would think that a DP is worth about the same as a CS over a regular out, roughly .2 runs.

3. You shouldn’t be using outfield assists. They’re worthless (they correlate negatively with actual arm rating done using PBP data).

I have some more but have to go right now.

Nice job.

If you look at the data in Chone’s spreadsheet, you can see that Floyd was actually rated as 8 runs for FBs and 8 runs for Arm.  He had 16 assists, and we’ve already noted that Chone may have the OF assists counting too much.

FLyd was “above average”.  However, I think Floyd’s 8 RS *is* the best in the NL (although Kelly Johnson does score well).

what htis helps to demonstrate is that BIP distribution is very important. 

Floyd did look better. He had fewer leg issues and he is pretty fast.

The numbers define how many FBs he caught (that applies to K. Johnson too), not how he looked . 

Say it with me - we’re aren’t selling jeans here.

Chris,

It’s GASSKO. No “r”.

My apologies.  I should stick with DSG.

You shouldn’t be using outfield assists. They’re worthless (they correlate negatively with actual arm rating done using PBP data).

I’ll suggest that baserunner holds (which is what I assume you are referring to with “arm rating from pbp data) is far more altered by the type of BIP in a given situation and the baserunner than the OF.  I like using OF assists, because there is some difference between OF and they are outs on base.

David,

1. Steals (and CS, WP, PB) are part of the DP calculation.

2. You’re probably right, CS is a good comparison.  I expect I’ll change a few weights before I do this for 2006 data.  This remains a work in progress.

3. Something to look into

I think assists have some value, because throwing a baserunner out is much more valuable than holding him one base.

I remember Bill James writing years ago about a weak armed OF with a lot of assists (Tim Raines?), saying that even if everyone’s running on him, there just is not enough plays available for those extra bases to hurt more than the 20 assists help.

Both the Rolen and Grudzelanik ratings lead me to suspect that the system may still have some trouble with groundballish pitching staffs.

I’ve always wondered what defensive rating should do about something like that.  Certainly, we wouldn’t want to call an average defender who recieves many fielding chances “great”.  However, let’s take two hypothetical 2B of equal skill.  If they convert (random number for the sake of the example) 75% of balls hit into their area into outs, but one player recieves an extra 100 chances, shouldn’t he recieve some credit if playing at an above average level for more time?  Just as its easier to hit .300 in 200 ABs vs. 450ABs, shouldn’t players who play above average defense get some extra credit for doing so in spite of more chances to screw up?

Perhaps fielding stat Nirvana would be similar to a batting line.  Instead of .310/.420/.604 in 650PAs, we would get +15 FR/500 (fielding runs per 500 chances) in 320 chances.

This would also be somewhat useful when evaluating a players role.  High K, flyball staffs do not rely upon infield defense, and a great defensive 3B will be of less value than to a team like the Cardinals.

You shouldn’t be using outfield assists. They’re worthless (they correlate negatively with actual arm rating done using PBP data).

For LF and CF, this is definitely true; guys with high numbers of assists also normally give up a lot of baserunner advances. For RF, it’s not (or it didn’t used to be, anyway - I haven’t looked at this in a couple of years); RFs who have good assist totals typically are very good at also preventing the extra base. There were a couple of exceptions (Mondesi was one, Dave Parker during his years in Pittsburgh was another) but not many.

I count triples as a baserunner advancement; there are no parks left like Forbes Field that are triple-friendly, and almost all triples are the result of a runner (even though they are mostly fast runners) taking a liberty with an outfielder. Some fraction of doubles should also be counted as a baserunner advancement, too.

—MWE

Both the Rolen and Grudzelanik ratings lead me to suspect that the system may still have some trouble with groundballish pitching staffs.

Zone ratings in the infield do correlate (to a small degree) with staff groundball tendencies, as do zone ratings in the OF to flyball tendencies (to an even smaller degree). I think the Rolen/Grudz ratios are driven to some extent by the DP factor; the Cardinals turned a tremendous number of DPs for the runners they had on base.

—MWE

The Cardinals had everything going for them in turning DPs:

1) extreme groundball staff
2) excellent work by the middle infielders
3) a catcher who kept lead runners nailed to first

I think the Rolen/Grudz ratios are driven to some extent by the DP factor

DPs aren’t in ZR anymore.

we would get +15 FR/500 (fielding runs per 500 chances) in 320 chances.

This is what my rating does…

DPs aren’t in ZR anymore.

No, but they are in Chone’s ratings, which is what we were discussing WRT Rolen and Grudz.

—MWE

Grudz is +17 just by zone, with DP’s pushing him up.

Rolen is all zone, the DP rating I use only covers the middle infielders.

Sorry, Mike, I had already known that Rolen had no DPs (they are not in his 3B ratings at all), so I assumed you meant ZR.

Boy does Texas have an awful infield.

Or their is something inherently weird about Texas’s ball In play distribution.

The way I would normally look at it to compare the starters to the backups and see if the results on a per inning basis were similar.  That approach won’t work for the Rangers since the last few years the Rangers have been getting 12-1300 defensive innings from the starters. 

Considering that Young and Blalock have fairly good reputations defensivly, I think its reasonable to assume until we KNOW differently that their is something unsual about the Rangers BIP distrubution, and the results for this specific team should be taken with a grain of salt.

AFAIK, Young doesn’t have a good defensive rep.

I would have a problem with the Texas ratings if in spite of these ratings, their pitching was good.

Since its not, I can buy that their defense is made up of butchers.

There could also be a ballpark effect in the Texas rating.  The only park factor I use is the Green monster factor.

I really have no idea how much a park affects ground balls.

Or their is something inherently weird about Texas’s ball In play distribution.

I doubt it.

Texas does have a slight groundball staff (reflected in the GO/AO rate and the HR allowed, which was unusually low for a Ranger staff). They gave up a huge number of non-HR hits, and allowed the most singles in the league by a good margin. That’s usually reflective of a poor defensive infield.

Oakland allowed the fewest singles in the league (close to 200 fewer than Texas), with a GO/AO rate and a HR allowed total not much different than Texas’s. The ranking for Ellis and Chavez are good, of course, and Crosby was +12, just missing the top group. I think those are fair assessments of the defensive performance of the two infields.

—MWE

I really have no idea how much a park affects ground balls.

Not much, any more, with high-tech groundskeeping methods becoming standard and teams resorting to less trickery along the lines of what Pittsburgh and the Giants used to do.

—MWE

Dial - You must not watch many Ranger games.  Both home and road announcers rave over Young glove.  Jamie Newberg also thinks highly of his glove.

I would have a problem with the Texas ratings if in spite of these ratings, their pitching was good.

I understand what you’re saying, but I don’t think it NECASARILLY follows.  I mean it might follow it might not.  I think the Rangers were 11th in park adjusted run prevention in 2005.  Its possible that the defense and pitching were equally poor.  Its possible that the pitching was mediocre and the defense was relatively worse than the 11th or the opposite could also be true.  I don’t think we know which of the scenarios are true, because we are so foggy on separating pitching from defense.

Mike - good points.

You must not watch many Ranger games. Both home and road announcers rave over Young glove.

I watch “some”.  I was never impressed.  And to be clear - not about his glove, about his ability to turn GBs into outs (low range left/right, not surehandedness).

This is what my rating does…

sweet.

I think assists have some value, because throwing a baserunner out is much more valuable than holding him one base.

In a Franoceur thread from august, someone suggested that the most valueable arm is the one no one knows about.  Kind of like how Pudge was so good early in his career that his value suffered because no one tried to run on him.

BTW is that true about Pudge? I wasn’t following baseball closely at the time.

Rauseo: The Rangers announcers are some of the worst there are. Incredible homers and little understanding of baseball. Michael Young tends to short arm throws and also doesn’t have particularly good range. Blalock also doesn’t have good range. Michael Young was well regarded by scouts as a defensive 2B coming up and Blalock was well regarded defensively too. I think it’s just likely those are wrong. I wonder how much road announcers end up just assuming that home announcers will be right about things like defense and agree with them. The Rangers announcers talk up Soriano’s defense and I know if you asked them they’d say he’s an above average defender who just has a *little* problem with his hands.

I agree of course with Sean Smith that Soriano and especially Blalock need to be traded. Kinsler isn’t supposed to be good defensively though, and his offense at AAA this last year wasn’t anything to write home about.

Watching the Rangers play a lot, and then watching the playoffs, the difference is really night and day. Plays that would spectacular plays for the Rangers fielders are made regularly by good defensive infielders.

Sean Smith: Can you post what Laynce Nix’s numbers were? Thanks.

Spivey, Nix was +5 ZR, average for assists/errors.

There is a link to an excel file at the end of the article.  All players with 250 or more innings at a position are included.

Ok. Thanks.

LF: Manny Ramirez –25, Hideki Matsui –9, David Delucci –9

That figure includes a park factor for Manny, the only park factor used in these ratings. He’s at –32 without it.

Manny is bad, but I have trouble believing that in 2005 he was almost as bad by himself as an entire outfield of Matsuis. Having seen a lot of both of them in 2005, this seems absurd to me.

Try UZR, then.  That system has Manny rated as -47, park adjusted.

MGL didn’t post NL numbers, but tells us Griffey is even worse.

3) a catcher who kept lead runners nailed to first

What made Yadier Molina even more valuable were all the pickoffs, which I assume aren’t counted above.

Is there any chance that the Texas infield bakes in the course of the summer and becomes harder than most infields thereby playing faster and making every player’s range seem poorer than it is?

Maybe, but if so Teixiera was unaffected.

What made Yadier Molina even more valuable were all the pickoffs

How many did he have?  If I can find a source showing pickoffs by catcher I’d include it in the ratings.

Is there any chance that the Texas infield bakes in the course of the summer and becomes harder than most infields thereby playing faster and making every player’s range seem poorer than it is?

DSG uses park factors in his numbers which also show the Texas infield to be terrible. I think UZR uses park factors as well, which shows the same thing.

How many did he have?

Eight or nine, I think. What makes it more valuable (and weirder) is that he mainly picked off trail runners with two outs.

If I can find a source showing pickoffs by catcher I’d include it in the ratings.

Retrosheet will have it, but I suppose that’s a way’s off.

Oh, and that’s a nice spreadsheet.

Your use of “Chone” as a pen name may get Furtado’s lawyers a little antsy though.

DSG uses park factors in his numbers which also show the Texas infield to be terrible.

Actually, I don’t. I’m with MAH here. Park factors are only required for a few situations.

MGL didn’t post NL numbers, but tells us Griffey is even worse.

Griffey was -59 in UZR/150. You read that correctly. -59. (And I hope MGL doesn’t mind me posting this. I’ve tried to avoid posting other ratings shared with me, but I assume Mitchel was going to post this rating anyways).

I’ll suggest that baserunner holds (which is what I assume you are referring to with “arm rating from pbp data) is far more altered by the type of BIP in a given situation and the baserunner than the OF.

UZR (and also what Protrade did maybe a month ago) adjusts for type of BIP, Base situation, etc. If done correctly, IMO, this is much better than assists. Mike E. is probably right about assists for right fielders. MAH has also found that errors are statistically significant for RF as well.

Steals (and CS, WP, PB) are part of the DP calculation.

Right, but what you’re doing is subtracting them from the number of men on first. Also remember that a steal means a man on second. You need to double count in this case. I’ve been doing a little research with this stuff; it’s actually very tough to get good DP ratings without having situation dependent data (which MGL uses for UZR). BTW, a good way to split credit for double plays (Chris, I think, was talking about how this is tough to do) is to base it on A/(A+E) vs. the average at a position. That generally gives you a good idea of a player’s “arm”, which I think would be the key to being good or bad at turning DPs.

Also, Chris, what use do you foresee for the DP started data? It seems to me that DP turned might actually have more value.

Also, Chris, I can provide you with data on other players if need be for your article.

Finally, post #44 is spectacular. A must-read to understanding defense on a conceptual level.

How many did he have?

Eight. I should have all of them by the end of the year.

—MWE

DSG,
is your data based on 162 games or actual innings played?

Actual. I can convert it esily if you’d like.

That could be driving down your correlation.  Could you generate it vs. 150 DG (1350 IP)?  I’ll send you an email.

Chris, just replied. And forwarded it to Aaron + Studes.

Re Floyd: I have to agree with Jeremy and Matt. Cliff looked spectacular in LF this year. He was throwing out runners left and right, running full speed, and even doing summersaults to catch balls.

BTW, if you don’t mind me asking, what were Reyes/Wright’s?

OFF, the last paragraph of the article has a link to a spreadsheet.

You can get the ratings for any player with 250 or more innings at a position.

I remember Bill James writing years ago about a weak armed OF with a lot of assists (Tim Raines?), saying that even if everyone’s running on him, there just is not enough plays available for those extra bases to hurt more than the 20 assists help.

Probably that was Vince Coleman.  If not, Vince Coleman is my personal poster child for this phenomenon.

ARoM, do you have overall team rankings?  I.e., did you run everyone, or just the 250+ guys?

I could put together team rankings.

Possibly by this weekend.

The thing is, when I add up the runs, I get +112.  I figger it should add up to zero, or pretty close to it, unless the scrubs were really atrocious all around.  So I mistrust the team totals one arrives at by adding up the 250+ guys.

Oh cool. Somehow I missed that.

For infield and outfield, everything should sum to zero, even the dp, assist, and errors stuff.  If it doesn’t when I add in the under 250 inning players, then I’ve done something wrong.

The catchers will not sum to zero.  The pb, e, wp, and sb attempts (the one used for keeping dp in order) will sum to zero, but the SB and CS are linear weight runs.

If all catchers threw out 50% or more of the runners, then catching as a group would have a positive run value, and you could blame it on stupid runners.  In reality, it comes out pretty close to zero.

My plan is to put together team totals, by position, and also compare to a team estimate based on DER.

I remember Bill James writing years ago about a weak armed OF with a lot of assists (Tim Raines?), saying that even if everyone’s running on him, there just is not enough plays available for those extra bases to hurt more than the 20 assists help.

Probably that was Vince Coleman. If not, Vince Coleman is my personal poster child for this phenomenon.

I was thinking it was Lonnie Smith….

Sounds good, thanks for listening, ARoM.

Sean,

Don’t compare to DER. ZR is much better. You should be using DIPS, and adding the two up to compare to runs allowed.

I want to compare apples to apples.  There are two ways to do this:

Compare DER to ZR plays saved (before converting to runs, a minor but important detail since I use a different run value for IF and OF)

Compare FIP + ZR runs (including dp/e/ast/catcher) to actual ERA. 

I might as well do both.

For infield and outfield, everything should sum to zero, even the dp, assist, and errors stuff. If it doesn’t when I add in the under 250 inning players, then I’ve done something wrong.

Sort of - the fractional run values make mine off by a run or two in various places.

I need someone to help me with the runs from FIP or DER.  I did that and it stunk.

Chris, what do you mean?

Quicker than I thought.

R values:

Der plays saved to zone plays saved: .58

FIP + (total my stuff) to ERA: .93

FIP to ERA: .85

So my ratings explain about half the difference between FIP and ERA.

Chris, spreadsheet is headed your way.

Rally,
my ratings and your ratings correlate at 0.97, for the guys we’ve seen from DSG and MGL (about 100 guys).

Oh, I removed DPs and arms from yours and tweaked to 150 DG, so mine, yours, MGL’s and DSG’s would all be on the same scale.  they’ll all be side by side shortly.

Technically, DSG’s has DPs and arms, but I think that won’t matter much.

My spreadsheet does every player.

Chris,

I don’t do DP or arm, so actually they’re all on the same scale.

Fantastic!

Thanks, David.

This is great.  At last we’re going to have multiple, independently
calculated, publicly posted fielder runs-saved ratings featuring
intelligently used zone and non-zone data.  Maybe we can combine the three into one system-the Chone-Dial-Gassko, or Composite Defensive Grade (“CDG”), system.  Unless Chone would like to use his real name, in which case we could call it the Grand unified Defensive System (“GuDS”).  ;-)

Some thoughts-

First, the ratings look very good.  The few times I’ve seen Cliff Floyd this past year he’s impressed me as a hustling player-a +8 runs saved excluding assists sounds reasonable.  Also, the rating for Manny Ramirez seems dead-on.  So often he seems to have no idea where a ball is heading.  I’m not surprised that the Red Sox management hasn’t been keen to keep him.

It’s difficult to allocate DP credit between second basemen and shortstops. I agree with Chris that it’s generally not worth the trouble, at least for contemporary players.  Perhaps the reason is that turning a double play well or poorly is a defensive skill that can be reasonably well assessed from observation (whereas range often isn’t), and players who can’t do it well just aren’t allowed to play at second or short.  If double plays are included, their run weight should be slightly higher than a walk allowed, or about .45, based on Tangotiger’s markov-type calculations and regressions I ran while developing DRA.  When you think about it, completing the double play prevents a runner from reaching first whose at-bat has minimal or negative runner-advancement value, even apart from the effect of the out at second, so it should be worth less than preventing a single.

Outfield assists are tricky.  In my historical DRA studies, assists do
matter a great deal in right field.  Jesse Barfield was the prime example. Also, the fact that the only errors that have statistical significance in contemporary DRA regressions are in right field probably reflects that such errors are predominantly throwing errors, in which the stakes are high.

MWE’s observation that most outfield assists are at second is also consistent with DRA.  The run-weight for centerfield assists is out .75,
whereas the run-weights at the corners are more like 1.25.  That probably reflects the fact that it is very difficult for a centerfielder, who plays deeper than corner outfielders, to _directly_ prevent a runner from scoring from third base.  I would imagine that most centerfield assists occur at second base.  Also as MWE observed, the difference between a double and a triple is largely determined by the rightfielder, no longer by park effects. Obviously, the DRA run-weights are high because regression weights “carry” non-measured factors that correlate with outfield assists and run scoring-such as, possibly, preventing runner advancement when no throw is made, as well as the run-expectation value of having a runner on third base before he scores.

The correlation results also make sense.

The DRAZR ratings I introduced in February at The Hardball Times, which are just a linear combination of DRA and my best attempt at the time to convert ZR into runs-saved, also had a .8 correlation with UZR _without_ any editing of the data.

The correlation between runs allowed and (FIP + your system) is also close to the DRA model accuracy, which is also about the same as the accuracy of models of team _offense_.

Finally, the correlation between your system and DER sounds about right, as flyouts caught by infielders (Infield Fly Outs, or “IFO”) are excluded, and DRA suggests that about 40% of the team-by-team variation in BIP run-prevention is explained by flyouts caught by infielders.  Naturally park effects come into play.  Since DRA allocates IFO outs to pitchers, that gives pitchers a meaningful impact that represents a modification of DIPS.

Does your system account for pitcher fielding plays?  If not, you might get an even better correlation result.

I’ve made a post to Chris Dial’s article about Zone Rating with some
suggestions for improving ZR on its own.  I think it still has some
significant limitations in the outfield, but they might be easily remedied using the suggestions I offer there.  Also, it would be interesting to use David Pinto’s outfielder ratings _without park effect adjustments_ and his infielder ratings with _only_ groundballs included.

Thanks again.  We’re making progress.

Watching Lonnie Smith play defense was a blast.