Friday, September 30, 2011

Discussions: 2011 Division Series

As the ALDS & NLDS get underway, we again feature the live UEFL UmpChat as well as some game highlights, below. Notes include home plate umpire performance according to pitch f/x and UEFL Rules 6.b.ii.a. (horizontal bound, "Kulpa Rule") and 6.b.ii.b. (vertical strike zone, "Miller Rule"). Plays include significant plays, if such plays occur. For future games, notes include home plate umpire probables. "If necessary" games are not included. Proudly updated on a Mac.

**We are live tracking select DS games, denoted by º, in real time. Reload this page for updated stats.**

Friday's covered games (both NLDS Game 5: Deciding Cardinals/Phillies meet D'Backs/Brewers in NLCS):
- Final: STL@PHI: Ending with 94.0%, Cederstrom wraps up the Division Series.
- Final: AZ@MIL: At 95.2%, Kellogg finishes with the second highest accurate game of the playoffs.

Thursday's covered game (ALDS Game 5: Deciding, Tigers meet Rangers in ALCS):
- Final: DET@NYY: With Barrett's <90.0%, the Tigers-Yankees series finishes with 683-768, or 88.9%.

Wednesday's covered games (both NLDS Game 4):
- Final: MIL@AZ: Bruce Dreckman finishes at 93.3%, having called the most pitches of any DS umpire thus far.
- Final: PHI@STL: Angel Hernandez finishes at 93.1%, having called the fewest pitches of any DS umpire thus far.

Tuesday's covered games:
- Final: MIL@AZ: In calling 90.7%, West scores the highest accuracy of any Division Series crew chief.
- Final: DET@NYY: Dan Iassogna calls <90.0% in Yankees blowout.
- Final: PHI@STL: Layne is the second crew chief to finish with <90.0% (Dale Scott).
- Final: TEX@TB: With 96.0%, Gibson has the highest accuracy rating in the Division Series.

Monday's covered games:
- Final: NYY@DET: Gerry Davis goes 90.2% after dropping 2.1% after the 7th inning.
- Final: TEX@TB: Calling 146-168, Dale Scott calls the 3rd most pitches of anyone in the DS, goes <90.0%.

Notes and Archives
All DS: Starting assignments place the crew chief at second base so that he will officiate Game Three at the plate.
TB@TEX, Gm1: HP Umpire Mark Carlson: pfx (53-56 Called Strikes, 99-109 Balls = 92.1%)º
DET@NYY, Gm1: HP Umpire Tony Randazzo: pfx (50-62 Called Strikes, 103-107 Balls = 90.5%)*º
AZ@MIL, Gm 1: HP Umpire Ron Kulpa: pfx (55-59 Called Strikes, 76-80 Balls = 94.2%)º
STL@PHI, Gm 1: HP Umpire Chris Guccione: pfx (41-44 Called Strikes, 73-76 Balls = 95.0%)

TB@TEX, Gm2: HP Umpire Kerwin Danley: pfx (41-47 Called Strikes, 92-99 Balls = 91.1%)
DET@NYY, Gm2: HP Umpire Eric Cooper: pfx (40-51 Called Strikes, 100-106 Balls = <90.0%)'
AZ@MIL, Gm2: HP Umpire Alfonso Marquez: pfx (41-46 Called Strikes, 106-113 Balls = 92.5%)º
STL@PHI, Gm2: HP Umpire Jerry Meals: pfx (47-50 Called Strikes, 88-95 Balls = 93.1%)º

TEX@TB, Gm3: HP Umpire Dale Scott: pfx (49-57 Called Strikes, 97-111 Balls = <90.0%)º
NYY@DET, Gm3: HP Umpire Gerry Davis: pfx (34-42 Called Strikes, 104-111 Balls = 90.2%)º
PHI@STL, Gm3: HP Umpire Jerry Layne: pfx (38-45 Called Strikes, 83-90 Balls = <90.0%)º
MIL@AZ, Gm3: HP Umpire Joe West: pfx (38-44 Called Strikes, 79-85 Balls = 90.7%)º

TEX@TB, Gm4: HP Umpire Greg Gibson: pfx (49-50 Called Strikes, 96-101 Balls = 96.0%)º
NYY@DET, Gm4: HP Umpire Dan Iassogna: pfx (38-47 Called Strikes, 82-90 Balls = <90.0%)
PHI@STL, Gm4: HP Umpire Angel Hernandez: pfx (30-34 Called Strikes, 65-68 Balls = 93.1%)º
MIL@AZ, Gm4: HP Umpire Bruce Dreckman: pfx (48-54 Called Strikes, 118-124 Balls = 93.3%)º

DET@NYY, Gm5: HP Umpire Ted Barrett: pfx (40-49 Called Strikes, 92-103 Balls = <90.0%)º
AZ@MIL, Gm5: HP Umpire Jeff Kellogg: pfx (49-52 Called Strikes, 109-114 Balls = 95.2%)º
STL@PHI, Gm5: HP Umpire Gary Cederstrom: pfx (34-38 Called Strikes, 76-79 Balls = 94.0%)º

DET@NYY, Gm1: Cano's hit off top of the wall is reviewed with instant replay, confirmed by Davis as an RBI double
AZ@MIL, Gm1: Ryan Braun throws out Bloomquist at the plate, perfect block, perfect call by Guccione
TB@TEX, Gm2: Danley rules David Murphy's bouncer in front of the plate foul despite no contact with catcher or bat
DET@NYY, Gm2: Cooper, Davis, Iassogna, Barrett, and Welke simultaneously call the obvious Logan balk
AZ@MIL, Gm2: Brewers' five run sixth inning features Dreckman and Marquez's balk call on Ziegler
AZ@MIL, Gm2: Looking in from the glare, James Hoye rules Aaron Hill's line drive a foul ball off the wall
STL@PHI, Gm2: Edited video of four angry reactions to Jerry Meals' strike zone (one of those, a correct call)^
STL@PHI, Gm2: La Russa complains on national TV about the strike zone; MLB has fined him for his actions^
PHI@STL, Gm3: Umpires confer, correctly overturn trap / catch call in right field to an out
TEX@TB, Gm4: Rodriguez and Napoli collide at home plate, Greg Gibson correctly gives two "safe" calls
PHI@STL, Gm4: Squirrel runs in front of home plate as pitch is caught, Angel Hernandez correctly rules a ball
DET@NYY, Gm 5: Girardi requests bandage removal; Barrett directs Benoit to remove the medical item

*Contest was suspended per MLB Rule 4.10 Comment. Randazzo's pre-suspension line was 9-11 CS, 18-18 B = 93.1%. This isn't the first the the Tigers & Yankees have been rained out in New York.
'The UEFL reports all sub-90.0% accuracy games as "<90.0%"
^As noted in this Bleacher Report article, Tony La Russa's complaints over Meals' K-zone were misguided.
ºIndicates a Live Update game. Reload this page during the contest for updated ball/strike statistics.


Anonymous said...

Wow, Guccione a solid 95% he is truly a rising star

Anonymous said...

Danleys info is wrong. Wrong fx link. He missed 10 strikes and had an awful game.

Jeremiah said...

Danley was 91%, not great by any means, but not absolutely awful either. What WAS pretty peculiar is Danley's 4th inning call on Murphy's hit out in front of home plate. Inexplicably, Kerwin calls it foul and kills the play. No reason for it to be a dead ball, was never touched by the catcher in foul territory, never touched the bat a second time in fair or foul territory...

Incorrect call. He got it wrong.

Dan said...

Great games by Guccione and Kulpa. Carlson was decent. Randazzo could have been better, but wasn't awful. Danley had an off night, especially with the call he blew on that dribbler in front of home plate.

It almost seemed like he knew that he screwed up, cause Joe Maddon didn't argue after Kerwin said whatever he said to him. It seemed like he said, "that's on me" or something to that effect, and if he did, then props to him.

Anyone know why they decided to have the crew chiefs do Game 3? It makes sense, because Game 3 is always a pivotal game in a series. But I was just curious, necause I don't think they've ever done something like that before.

Anonymous said...

I don't think Gooch was the HP in the Braun play? Just saying, Gooch is 68, that umpire was forty something...i couldn't tell.

Anonymous said...

Apparently Danley thought that Murphy's bat hit the ball on the back swing.

Anonymous said...

How can you say that any borderline call is correct. Any pitch that touches the outline by even the smallestvamount is being considered correct. Makes no sense. If Danley ruled those pitches a ball or a strike he can't be wrong using your formula but you can't count all as correct.

Gil "R.O." said...

The Miller and Kulpa rules as they relate to Pitch f/x, normalized vs unnormalized strike zones, planar fallibility, and margin of error have been discussed at great length over the course of this past season.

In regards to the Kulpa Rule (6.b.ii.a.)...
First, we must determine the width of the working horizontal planar strike zone. We know the plate is 17" in diameter, or 8.5" on either side (radial value, Rule 1.05). We also know a regulation MLB baseball must have a circumference no greater than 9.25 inches (Rule 1.09). Circumference = pi * diameter; therefore, diameter = circumference / pi; diameter = 9.25 / 3.14159 ... = a baseball's maximum diameter is 2.944 inches. Since there are two sides of home plate that any part of the ball may pass through and still be within the strike zone, the working horizontal planar strike zone is 17" + 2.944" + 2.944", or 22.880 inches wide. The radius, therefore, of the working zone is 11.440 inches, which converts to approximately 0.953 feet (pitch f/x charts use a horizontal unit of feet).

Pitch f/x carries with it a margin of error of approximately one inch, per the manufacturer. One inch is 0.0833 feet. By adding and subtracting 0.0833 feet to the observed px [horizontal] value, we create a confidence interval (of 100%): we know the pitch definitely was somewhere within this range. Computing the confidence interval (CI) for any pitch yields a 0.166 foot range. Per our calculation above, the range of "definite strike" includes values between -0.953 feet and 0.953 feet, where negative values refer to the graph's left side [right handed batter's side] and positive values refer to the graph's right side [left handed batter's side].

Under the Kulpa Rule, certain pitches that show as 50/50 or somewhere in the midrange are considered "borderline." For us, a determination of "borderline" routinely reflects the call on the field as correct. Generally speaking, we consider any legal pitch between 0 and 0.900 to always be a strike, between 0.900 and 1.000 to be borderline, and above 1.000 to be a ball (if there was no swing, etc.). An umpire cannot receive CI (call incorrect) for a play in which replays and other technology fails to show that the call was conclusively incorrect.

Also note that the pitch f/x strike zone "box" is not used in our calculation of correct/incorrect calls. We use numbers and only numbers. We do not use the box, which is limited in scope. Numbers, formulas, and calculations are not limited.

As for the Miller Rule (6.b.ii.b.), the formula reads as follows: "sz_top + sz_bot / 2 = C... |C - pz| = D... norm_ht / D = R... 0.0833 * R = E... norm_ht + E = [Lower Bound, Upper Bound]. If this range of [Lower Bound, Upper Bound] is completely greater than |1.000|, then the correct call must be a ball. If this range of [Lower Bound, Upper Bound] at some point is less than or equal to |1.000|, then the correct call may be a strike.

We create confidence intervals for every single pitch,and using approved thresholds, calculate Quality of Correctness.

This works very similarly to Hawk-Eye, the system used in tennis, in which ball location is calculated using a statistically probable path. Hawk-Eye also contains a margin of error. Because Pitch f/x does not calculate a statistically probable path (or point), we must do so after the fact; to do this, we use the margin of error and 100% confidence interval system. This method is mathematically, scientifically, and most importantly, objectively sound.

Anonymous said...

I LOL'd when I heard the broadcasters, in regards to the balk, say, "The pitcher balks, and I was watching the six umpires, and all six hands went up."

Seriously... what are the left field and right field umpires going to do in a balk? No one's going to hear them...

Anonymous said...

There was a really good balk call in the 6th inning of the brewers D-backs game.

Anonymous said...

Pretty funny that when MLB puts together a video to show that Meals has a bad strike zone, they include a clip of Pujols getting upset after a called strike three... even their little pitch chart showed it was CLEARLY a strike.

Jack_1B Ump said...

That's ridiculous what MLB does with the Meals K-Zone video. Jerry had the highest % strike zone of the day. He was the best HP Umpire today. And MLB makes him look like the worst. That's awful.

Anonymous said...

Crew chief day coming up!

Anonymous said...

What I'm interested to see is whether the Yankees/Tigers crew turns around their % game, maybe it's the Yankee Stadium atmosphere.

Anonymous said...

OK gil

How about telling us the percentage of strikes hitting the strike zone that are called balls, versus the percentage of balls that do not hit the strike zone being called strikes. Just an overall number for everyone so far, although you can probably break it down for each plate job by each umpire.

Just trying to see if the calls show umpires to be more hitter friendly or more pitcher friendly, and by how many if you want to break it up into the exact numbers, or percentage wise if you chose to do that. Thanks.

Scott said...

Why does the UEFL report all sub-90.0% accuracy games as "<90.0%"?

Gil "R.O." said...

The idea is similar to basketball reporting 10+ fouls instead of 11, 12, etc.

A game called below 90% is generally considered significantly below average whether it is 89.9% or 50%. We give the exact percentage above 90.0%, where most performances end up, but in terms of measured accuracy below 90%, it is simply our preference.

In basketball, after you have 10 team fouls and are in double bonus, 11, 12, etc. don't matter.
For the UEFL, if you are below 90%, it is significantly below average. It doesn't especially matter the extent to which, it is already significantly in that direction.

Hope that helps...

Anonymous said...

Gil, you're way PC. That's a good thing though.

What Gil really means to say is "I don't want to kick an ump while he's down."

For an umpire site, I think that is a good philosophy...

Anonymous said...

Any reason why up to now the NL Umps are dominating the accuracy charts? So far no ALDS ump has called a better game than any NLDS ump. Did MLB give the NL better umpires?

Dan said...

Certainly not the best night behind the plate for Dale Scott or Gerry Davis. You expect better from veteran guys like them. It will be interesting to see how West and Layne do tomorrow.

Anonymous said...

If the crew chief big boys take care of business tomorrow, that'll save MLB's experiment of having the chiefs take Game 3 of the DS. If not, don't expect to see this odd rotation back again next year.

Anonymous said...

No Gil

I do not want the individual statistics for each umpire, just for the group as a whole.

Are the umpires calling more strikes that are really balls as a group, or are there more balls that are being called strikes by the group and what is the percentage? Heck, you are already rating them individually on how many they are missing percentage-wise anyway and you are breaking it down individually.


As a group so far, of the pitches missed, 40% were
called ball that were in the strike-zone and 60% were called strikes that were out of the strike zone.

I do not want this individually actually, just to see if the umpires as a group tend to be what some people would refer to "pitchers" umpires or what some would refer to as "hitters" umpires.

Just my gut feeling is that as a group they are hitters umpires by a wide margin.

Anonymous said...

Could you imagine what a mess it would be if the balls and strikes were exactly as the Machine says?!! When the catcher sits inside and he reaches way over trying to just catch a pitch that actually hits the outside corner. The umpire technically gets that wrong. Or when a curveball actually hits the zone but the catcher's mitt hits the ground when he catches it. Nobody including the pitcher, catcher, announcer & fans think that is a strike, but we are talking that as a missed pitch and saying they scored 92.4% or whatever! How many knee pitches does the machine say strike on that look super low on TV that nobody blinks on because it looks low to everyone! Balls are balls and strikes are strikes, but the catcher has a huge part in how consistent an umpire "looks". Some scores can be high because the catcher & pitcher did what they wanted and threw and caught the pitch where and how they wanted. Some scores may be lower because that didn't happen. All we see is dots on a box, we don't remember that the catcher had to reach 2 feet to catch and nobody else thought it was a strike either! It would be a nightmare if the umpires scored 100% everynight, nobody would believe them except a computer. I hope MLB is smart enough to know that a 92% may be better then a 99% sometimes.

rth54 said...

That is a very good observation.

Gil "R.O." said...

@4:25 AM, As soon as the four Division Series are decided, I'll go ahead and compile the data. For the time being (let's say, through the Game Twos), we are 368-415 Strikes and 737-785 Balls, or 92.1% overall.

This is 88.7% in Strikes and 93.9% in Balls. With 47 missed strikes and 48 missed balls, it looks like a pretty even split. Remember, though, that there were 1.9 times as many ball calls to make as strike calls to make. That points to a greater proportion of missed strikes, and a collectively pitcher friendly group of umpires.

Anonymous said...

Sorry gil

I was having a dyslexic moment and was not reading the charts correctly. It looks pretty even as you surmised with the pitcher umpire versus hitter umpire. I would have guessed it would have been at around 60 percent in favor of the hitters, but like you said, it is pretty even.

This also proves that the best umpires, amateur or pro are missing the same amount of pitches percentage-wise as a group also. The old saying, I only miss 2 or 3 pitches a game statement is a bunch of crapola.

Anonymous said...

How would that prove what and how many pitches amateur umpires are missing or getting right?

Anonymous said...


I have never, not once, tried to call a 17-inch plate. I call pitches just off the plate strikes and I will use how the catcher catches the pitch as an element in my decision. I'm sure if Pitch f/x was on my game, I'd be well under 90%. And if you asked me, I'd say I only missed a couple of pitches -- cause some of those "incorrect" calls are ones I would call that way again, regardless of what a computer said.

Anonymous said...

Actually the umpires this year were very high.. 94% on balls and strikes..your calculations are not the same the MLB uses, I was talking to a MLB umpire this past weekend, they use a different system with cameras...

Gil "R.O." said...

@7:57 PM, Correct, I believe they still use Zone Eval whereas we use Pitch f/x?

Let's be honest. Whatever system we use here, however scientific we might be, MLB's own technology (and opportunity) will always prevail.

Anonymous said...

Technically, you shouldn't call a 17inch plate. 17+almost 3 on both sides...22.7-23.0inches of strike-worthiness.

Ball catches plate=strike.

Dan said...

I think it's pretty amazing how the younger umpires are out shining the crew chiefs so far in this postseason. West, Scott, Layne, and Davis were all around or below 90%, while you see guys like Greg Gibson at 96%, Chris Guccione at 95%, Ron Kulpa at 94%, among others. The future of umpiring in MLB is very bright.

Anonymous said...

I really think that the amount of importance everyone is giving these ball/strike %s is a joke. I don't think the best umpires would want to hit 100%, if you hit 100% then you definitely have called some pitches balls that you should have called strikes, and vice versa. Now of course, if there are a lot of obvious missed pitches during a game, that is something to look at. But unless these pitches are extremely obvious on the pitch f/x plot, it's hard to know if they really were missed or not.

Using the pitch f/x data, along with the video of the pitch, is the only way to determine if a pitch was a miss or not in my opinion. If you just look at the raw data, or the pitch f/x chart on it's own, then you really don't get a clear picture.

Gil "R.O." said...

Personally (and I might just get mauled for this), if someone is a proponent of using instant replay or a computer for balls and strikes, I'd just send them to this thread.

Having said that, Pitch f/x figures for guys like Gibson and Guccione really shows how good those specific umpires really are, not to say anything about the others. The crew chiefs may not have had the highest numbers, but I don't think anyone is going to be calling Gerry Davis a bad umpire any time soon. And the same goes for Dale Scott, Jerry Layne, and Joe West.

Anonymous said...

RE: "Barrett asks Benoit to remove bandage on face. Was this the right call?"

No. It's clear as night & day that there's a cut under there. It's a medical issue and a bad call to force him to remove the bandage.

Anonymous said...

Gil, Pitch f/x is fundamentally flawed, you know, I know it, the rats know it. 1st of all I herd John McSherry explain how at the big league level, the ball must pass through a majority of the strike zone. Pitches that just nip the edges, and don't stay in the zone, should be left alone and called balls. Argue if you like about the explanation, but it was said by the greatest ball and strike man of all time.
So Pitch f/x doesn't consider my previous statement. It doesn't consider where the previous pitch was. We all know 3 high pitch's over the top of the zone, and then a borderline low pitch, will most likely result in a ball call. A good coach will even tell his pitcher, the pitches need to be around the zone to get borderline calls. So that's another thing that is not taken into consideration by Pitch f/x.
The most glaring fundamental flaw is the judgement, by Pitch f/x, of the low part of the zone. If the umpire has consistently called balls on the low pitch, a consideration should be noted so that any pitch's lower are balls, and any pitch's higher would be strikes. So anything that doesn't fit that criteria should be considered a incorrectly called pitch.
But Pitch f/x sets the bottom of the zone, and will say the umpire missed 9 pitches, when the umpire really never called anything lower than his lowest strike (pitch).

And of course the young guys will have a better percentage than the CC's.
There's no consideration for consistency. I guarantee if all the pitches could be graphed down to the 16th of an inch, the old timers would be far ahead in percentages. "if" the bottom of the zone was more fairly set by pitch f/x.

Scott said...

Anonymous 12:45, while I don't necessarily disagree with you, I think Gil and this site are trying to analyse calls with the greatest objectivity possible, so that means following the rule book to the letter of the rule. Of course one umpire can be more consistant - and even more "accurate" to viewers and players - than another and score a lower percentage. Of course Pitch f/x, in its objectivity, doesn't consider the location of the previous pitch - each is judged on its own according to the rules of baseball.

While it is interesting to look at this so objectively, and I think all umpires should strive towards perfection as accorded by the rules, I don't think a higher score necessarily means that an umpire is better at calling balls & strikes.

Big Marc said...
This comment has been removed by the author.
Big Marc said...

@Scott- That was me at 12:45am. I was not taking a shot at Gil, I love this site and spend more time reading here than on my homepage. I was just directing my comment at Gil. This site is beyond fair. As an example, only going as low as 90% accuracy on plate job is an integrity call. 90% is clearly low, there's no reason to pile on a guy. And then the explanation of WHY 90% will always be the lowest is even better.

(for the winter we should have a Mexican UEFL)

The discussions here are better than being a member in the actual league. Plus like all fantasy sports, it ruins the game. (tongue in cheek)

Big Marc said...

Gil "R.O." said...

Personally (and I might just get mauled for this), if someone is a proponent of using instant replay or a computer for balls and strikes, I'd just send them to this thread.

I'm not mauling you, just wanted to hear you elaborate on this comment. I've read the entire thread, but cannot understand what you were trying to say. (probably because I'm a dumb umpire)

Gil "R.O." said...

Basically, we are trying to be as objective with pitch f/x as we can: "objectively track and analyze."

Pitch f/x tracks a zone and produces an instantaneous data point, values for "px" and "pz," a "norm_ht" with "sz_top" and "sz_bot." Using all that data, we come up with "correct" or "incorrect." No lee-way for a pitcher missing up, down, left, or right. No consideration for fastballs vs breaking balls, sliders or sinkers. When it comes to called strikes and balls, it's purely a numbers game.

And that's precisely why we shouldn't be using a computer to call balls and strikes during a game. The intangibles of pitchers missing spots, a cutter vs an eephus pitch, a 3-0 count or a 0-2 count, these are all considerations that a computer cannot take into account. So while we might very well have an "incorrect" call for a certain pitch - and let there be no doubt: by rule an "incorrect" call is truly "incorrect" - it still might be "right" to call it "incorrectly" depending on the intangibles that the human element can consider, whereas a computer cannot possibly get it right.

BTW: Sportvision CEO Hank Adams recently went on record with the LATimes claiming that Pitch f/x is more accurate than we thought: instead of to within 1", he claims it is accurate to within 0.5".

Anonymous said...

Gil "R.O." said...

@7:57 PM, Correct, I believe they still use Zone Eval whereas we use Pitch f/x?

Let's be honest. Whatever system we use here, however scientific we might be, MLB's own technology (and opportunity) will always prevail.
October 6, 2011 1:20 AM



exactly what is the difference in Zone evaluator and pitch F/x. Do they use different cameras? If so, where are the ZE cameras compared to the cameras used by F/x? What is the difference in the placement of the different cameras. Or, are the same cameras used, but a different software system and computer evaluation system in place with different algorithms or whatever? What is the difference in the percentage called correctly in the 2 systems. Lets get the lowdown on the 2 systems, it doesn't have to be a secret. Does ZE give the umpires a higher percentage called correctly and how much higher compared to F/x. ie 1%, 2%, 3% whatever. Give us the scoop or find someone who knows the in's and out's of both systems.

Gil "R.O." said...

When Mike Port was asked about Zone Evaluation by the New York Times in 2009, he stated Z.E. was quicker and more accurate than QuesTec.

When Steve Palermo was asked about Pitch f/x by 60ft6in's Rick Swanson as it relates to Zone Evaluation, however, he stated that PFX is inaccurate, has a margin of error between 3-7 inches, and that Z.E. is simply more accurate.

When then-Sportvision CEO Marv White was asked about Pitch f/x during the 2009 PFX Summit in San Francisco, he stated that PFX is accurate to within one half inch.

It is unclear exactly what the specific differences are between PFX and ZE. Palermo maintains that PFX is inferior technology to ZE, though he doesn't appear to have actually explained why that is.

In 2009, the Hardballtimes and Complete Game Consulting's Harry Pavlidis described ZE as a "Pitch f/x 'Plus'." According to Pavlidis, ZE is based on Pitch f/x, but allows for some post-game tweaking (called "post-game processing") to change the data displayed on the ZE plot, whereas PFX would produce the exact same plot, sans the post-game "processing." Ergo, ZE is PFX "Plus."

According to the description provided by Pavlidis, it would be reasonable to assume that ZE and PFX share cameras, share raw data points, and share tracking information. ZE simply is an "adjusted/fine-tuned" version of PFX.

PFX is of course public, while ZE is not. Unfortunately, we don't know whether that means that MLB intentionally alters data to produce higher accuracy percentages, whether ZE takes into account that curveball and give it more "lee-way" than it would a fastball, whether ZE "adjusts" to how an umpire calls the bottom of the strike zone.

What we do know is that pitch f/x contains raw data with no manipulation. Frankly, in reading about PFX versus ZE, I much prefer to use PFX on this website anyway. ZE is too secretive and raises too many doubts over what "post-game processing" actually means. PFX sounds far more objective and scientific than ZE.

Anonymous said...

Thanks Gil

Here is an article you might like to read if you haven't already. Not as nuts and bolts as yours, but another article on the subject.,0,1559031.story?page=1&utm_medium=twitter&track=rss&utm_campaign=Feed%3A%20latimes%2Fsports%20%28L.A.%20Times%20-%20Sports%29&utm_source=twitterfeed

rth54 said...

Perhaps I did not read it very well, but, the LA times article is a bit misleading as it seems to suggest that Pich FX is the same as Zon Eval. In fact it refers to the "Pich FX zone evaluation system" as the system that replaced Questec.

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