Neil Weinberg FanGraphs Q&A – 7/23/14

Neil Weinberg: Hey everyone, let me get you caught up.

My job here is primarily to serve as something of a Site Educator. This means that I’m responsible for providing resources to readers about our data, advanced metrics, and how to make use of the features available at the site.

My Twitter handle is @NeilWeinberg44 and if you want to get in touch about these kinds of questions at times other than 3pm on Wednesdays, that’s where to find me. It’s my job, so take advantage of it.

With that said, I will prioritize “how does this work?” and “what does this mean?” type questions during the chats, but feel free to ask regular questions about anything as well. Although if you’re here for fantasy advice or prospect talk, I’m probably less helpful than some of our writers.

Think that’s it, queue is open and we’ll start at 3pm!

Neil Weinberg: Alright, let’s chat.

Comment From Pale Hose
Hi Neil. Welcome back. I’m trying to walkthrough the part 1 of the WAR calculation for hitters. Dave uses the example of 2008 Adrian Beltre. I can match the wRAA on the player page (3.5), but I don’t follow the park adjustment. Somehow I am supposed to take a 96 Safeco park factor and come up with a batting value of 5.9 for Beltre. Can you help with this?

Neil Weinberg: This is probably too technical to walk you through in detail during a chat, but his wRAA is 3.5 and his Batting Runs are 4.8 for that year. I assume the values changed when we adjusted replacement level, so the exact values Dave and wrote about aren’t exactly correct.

I just did a very quick pen and paper calculation and got 4.7something. I’ll cover the specifics of all of these things as I update the glossary, but if you ever need specific clarifications, get me on Twitter.

Comment From Paul
Q about defense stats: if a player robs a HR, does he automatically gets 1 run saved? does it go to 4 runs saved if the bases are loaded?

Neil Weinberg: It depends on how difficult the play is. So basically, you care about how often the average defender would also rob that home run. Unfortunately, not as simple as +1 for solo HR robbing.

Comment From Paul
How do you translate a good defensive play into a run saved?

Neil Weinberg: Similar answer to the one above. You’re essentially talking about the run value of the play dependent on how often that same play is made by the league average player. We have some old posts on UZR that can walk you through this, but I’ll be updating the exact mechanics in the future so that you can get a quick tutorial.

Comment From Tucker
Dave said in an earlier chat that the difference between using wRC+ and wOBA is that the former is park and league adjusted, and the latter is not. Why isn’t wOBA adjusted for these things?

Neil Weinberg: Basically, because wRC+ is. wOBA is the raw production, wRC+ is adjusted for league and park.

Comment From Guest
Are the park effects that go into wRC+ and WAR broken out by handedness? If not, doesn’t it overrate or underrate certain players in extreme parks?

Neil Weinberg: They are not. Park factors are pretty complicated to get right, when you think about it. We have split park factors available on the site, but you could imagine getting really granular and breaking it down by fly ball and ground ball guys, etc. The basic ones work pretty well, but always be aware that there are going to be times when they aren’t perfect.

Comment From Guest
Any thoughts on the Bill James Online article that the positional adjustment for catchers might be too low?

Neil Weinberg: I think it’s an interesting question. There’s a thread on tangotiger.com right now discussing it. A couple of the possibilities being discussed are the fact that we don’t fully measure catcher defense and that if you are terrible at catcher defense, you get moved off the position very quickly.

I think that we’re all pretty sure we don’t properly capture everything we need to about catchers, but I’m not sure if it’s the positional adjustment that needs to change. Need to look into it more.

Comment From Guest
When would you say is an ETA in having catcher framing added to catcher WAR?

Neil Weinberg: I don’t know the answer to this but I know that we’re not going to do it until we feel like we’ve really figured out how to implement it properly. At this point, look at catcher WAR and make some personal adjustments based on framing numbers from various sites.

Comment From Farting for Science
I have a sneaking (and biased) suspicion that the Orioles wi be a good playoff team, because their starting pitchers are just bad enough to yank them for the more appropriate relievers. Is this crazy?

Neil Weinberg: This is an interesting thought. The idea is that if your starters have too long of a history of success, your manager will leave them in too long. Not sure if the Orioles have the pieces to properly leverage this, but I can imagine it having some non-zero effect

Comment From JTR
I’ve read the glossary section on these stats, but can you explain to me FIP, xFIP, and xFIP-? the differences between these 3 confuse me to death.

Neil Weinberg: First off, if you ever see a +/- at the end of a stat, you’re just looking at the park and league adjusted version of the stat. So xFIP- is just xFIP with a park adjustment and scaled to league average

Neil Weinberg: FIP is an ERA estimator based on K, BB, HBP, and HR. xFIP is exactly the same except that it tries to normalize the number of HR you allowed by taking the number of fly balls you allowed and applying a league average HR/FB%. So if you allowed 100 fly balls, it charges you with 10 HRs.

Comment From Vslyke
Have you all ever considered adding college stats to Fangraphs? I would love to be able to see FIP, K%, and all that good stuff for prospective draftees.

Neil Weinberg: I’m sure it’s been discussed at some point, but the data is much harder to gather, so I wouldn’t anticipate it happening any time soon.

Comment From Joe from the Ozarks
Are there any mainstream misunderstandings of the SABR mindset that really irk you? For me it is the thought that numbers and detailed analysis get in the way of enjoyment of the sport.

Neil Weinberg: This is a big one. I’m huge into the numbers and I enjoy baseball as much as anyone.

Neil Weinberg: Also, the idea that we ignore the fact that players are influenced by psychology is silly. We just don’t make up narratives about what players are thinking.

Comment From beep
Why is there a difference between projected RoS WAR and the updated WAR projections for some pitchers? e.g., yu darvish’s updated projection has him finishing with .4 more WAR than you get by adding his current total to the RoS projection

Neil Weinberg: I think this is a probably the result of how we calculate the WAR projection compare to what inputs ZiPS/Steamer include in their RoS. This is a good question for Appelman. Might want to use the Contact us thing at the bottom of the website.

Comment From Patent Pending
Would any additional rigor be added to RE24 by league- and park-adjusting it?

Neil Weinberg: I’m about 90% sure it is park adjusted. But a rate stat version might be fun

Comment From #KeepNotGraphs
Where can we find the article you wrote last week? I don’t see it in the FanGraphs articles.

Neil Weinberg: The FG Library blog, found here. http://www.fangraphs.com/li…

If you click the tab at the top right called ‘glossary,’ you’ll get there. Here’s the direct link to my piece. http://www.fangraphs.com/li…

Comment From Guest
I fear my 2 year old will never remember what it was like when the Cubs were bad.

Neil Weinberg: There are teenagers who think the Red Sox win all the time

Comment From alex
I graduated from Penn State in 2013 with a BS in Information Science and Technology. I learned some SQL while there. What are some other software products that I can learn that could help me get a job with some of the data analytics entities in the baseball field.

Neil Weinberg: SQL is big. Knowing something like R is good. I’d also recommend some knowledge of programming and creating software and user interface. Although, I’m basing this on secondhand knowledge, given that I don’t actually have most of these skills.

Comment From hits mcgee
Could you kindly explain what I can learn from RE24?

Neil Weinberg: RE24 tells you how much a player increased his team’s change of scoring, essentially. So if you get a hit with a man on first, RE24 gives you more credit than if you got a hit with no one on base. Think of it as context-dependent batting runs.

Comment From SEAfahrer
I couldn’t find anything in the glossary on RE24 (thought I could be blind), but I heard this was a good stat to learn about, was wondering if you could briefly explain and possibly link to somewhere to read further about? thanks

Neil Weinberg: Yeah, so for some reason this doesn’t exist. There are a couple posts below that will help, but I’ll put something together on this in the future.

http://www.fangraphs.com/bl…
http://www.fangraphs.com/bl…

Comment From BillyBob
Where can we find data for hard contact?

Neil Weinberg: Not publicly available at this time, although Mark Simon (@msimonespn) tweets out a lot of data on it, so he can usually help you out if you want to know something specific

Comment From Tucker
Are you a fan of RE24? Also what does the 24 stand for?

Neil Weinberg: Whoops, just realized my name wasn’t on.

Neil Weinberg: Alright, I like RE24 as a comparison tool. Look at a guy’s OFF and compare it to his RE24 to see if his production is coming in “key spots.” The 24 stands for the 24 base-out states (1,2,3 outs, and the 8 different baserunner arrangements)

Comment From David
What is wOBA Scale and how is it determined?

Neil Weinberg: wOBA scale helps you convert wOBA to runs per PA. I don’t know the exact mechanism to derive it off hand.

Comment From Andrew
Would there be any merit to including net SB in a modified SLG to determine simple offensive value?

Neil Weinberg: You could do this, but it’s not much harder to look at the run values already provide at the site.

Comment From John
If a player took extra BP or changed his swing prior to the game should we project him to hit better that game? Why?

Neil Weinberg: I don’t think we can know for sure. The argument would be that more work would improve the player, but it could tire them out or be a symptom of struggles they have yet to fix. My answer is basically that I have no idea.

Comment From Guest
Is there a way to translate replacement level from one era to another? Basically, is there a way to theoretically place Babe Ruth in 2014 and see how he would do?

Neil Weinberg: I remember someone talking about this once. Might have been Ben and Sam on EW or Dave and Carson, but you would need to do a long chain of comparison of overlapping players. Seems super hard…but I think it’s safe to say the overall talent distribution has shift way to the right, but I don’t know by how much

Comment From save notgraphs
Hey Neil, How are positional adjustments calculated for DRS/Def? I’ve never been able to find anything explaining that. I get that UZR can only be compared among single positions, and that’s why you have to do the positional adjustments. I’m just not sure how it’s been figured out that a CF is +2.5 runs, 1B is -12.5 runs, etc.

Neil Weinberg: Basically, you’re talking about comparing how players perform when they play multiple positions or change positions. Tango always uses Willie Bloomquist as the example. I think it’s worth re-evaluating the exact numbers, but they typically work pretty well.

Comment From Northsider
Is there a stat that tracks the weight of a SB? For example, factoring in stuff like the increased % of scoring a run, actually scoring a run, or avoiding a double-play opportunity

Neil Weinberg: RE24 includes this to some degree.

Comment From RetireNutting
I think the numbers and analysis *do* get in the way of enjoyment of the sport — for those who don’t at all understand them. Imagine having a foreign language pop up all over the screen every time you watched baseball. That’s what it must be like for those who aren’t fluent.

Neil Weinberg: But the numbers aren’t difficult to understand. I can explain wOBA to someone with no statistical knowledge in less than 5 mins. I agree the first time you see them, you would feel confused, but at some point you ought to learn the language or learn to ignore it. You wouldn’t go to Spain and get annoyed that everyone is speaking Spanish.

Comment From More Like “Whine Burg” Amirite
How many dingers do you think Stanton could hit if he played for the Rockies?

Neil Weinberg: 57?

Comment From Gila Monster
Could we see K% and BB% replace K/9 and BB/9 on the Dashboard?

Neil Weinberg: You can customize your own dashboard! If you’re signed in, there is a gray banner that says “welcome name…” Click customize and go crazy.

Comment From Chris
What goes into the playoff odds page? Does in take into account strength of schedule, RoS WAR projections of the roster, historical season outcomes of teams in the same position?

Neil Weinberg: We have a couple versions, but it’s basically RoS projections used to simulate every game.

Comment From Todd
What is the difference between RE24 and WPA?

Neil Weinberg: RE24 is measure in runs. We also have REW, which is the same thing translated to wins. So that gets you on the same scale. WPA takes into account score/inning, which REW only cares about influence on run scoring.

Comment From Tom
How are you enjoying being part of the Fangraphs community then? Got to be pleased with the popularity of the new chat and your articles so far. Best and most needed addition in a long time IMO. Very much looking forward to your glossary updates, as many of the pieces on there are quite dated now. Nice one and thanks.

Neil Weinberg: Thanks, I appreciate that. No complaints so far. I’ve been really pleased with the feedback and number of people who are so interested in learning about the site/data.

Comment From Anton
Say a player’s true talent wOBA is .350 (and we know this. Maybe think of it as his 10 season average wOBA). 25% through his season, his wOBA is .330. So when predicting what his wOBA will be at the end of the season, is it still wOBA, or is it .25*.330+.75*.350? Would this still hold in a smaller sample (say, after 1 game of .330 wOBA)?

Neil Weinberg: So, basically the answer is you project them to hit .350 wOBA the rest of the season, which will equate to a .344 wOBA or whatever. However, you would also slightly downgrade their RoS forecast based on the .330 start. So probably like .342 or something.

Comment From Gila Monster
What sample size do we need before trustinflg UZR to be accurate?

Neil Weinberg: There is no such thing as a perfect sample for ANY stat, but UZR needs longer than other stats to get to the point where it tells you about true talent. So after three years, you have a good idea of how good a guy really is, but I would trust a full season of data as a reflection of how the guy happened to play that year.

Neil Weinberg: If Miguel Cabrera hits .260 this year, you wouldn’t say batting average is inaccurate. You would say, he hit worse this year.

Comment From Tom
Just wondering how career wRC+ is calculated? How is each years data weighted and is it easy? Thanks.

Neil Weinberg: I’m going to have an entry up on this tomorrow or Friday, but it’s actually reasonably easy. You take a players’ wRAA/PA + MLB average R/PA + park-adjustment runs per PA / AL or NL R/PA and then multiply by 100.

Neil Weinberg: I’ll walk through this in detail in a day or two, in case that looks like nonsense!

Comment From Mike
Will any clean player ever top 73?

Neil Weinberg: Theoretically, yes. But how will we know he’s clean?

Comment From Doctor Doom
This might be a dumb question, but can you explain why a player might have a significant difference between their FIP and their ERA+? I assumed it had to do with bad defense but look at David Price who’s had a good FIP over the past few years but a mediocre ERA+…even though the Rays have had a great defense

Neil Weinberg: So one thing is that ERA+ and FIP are on totally different scales. You would want to compare ERA- and FIP-. Typically, it is some combination of luck on balls in play, defense, sequencing, ability to hold runners, etc. So I’m not sure if you’re mostly being thrown off by the park adjustment of ERA+ or those other things

Comment From kevinthecomic
Re: the weight of a SB question — Baseball Prospectus (at least I think it is them) has a stat called Base Running Runs (or BRR) that measures how many runs a player generates through things like SBs, going 1st to 3rd on a single, and the like.

Neil Weinberg: Ah, we have BsR! Which is wSB and UBR. That covers those types of things. Sorry I misunderstood your question.

Comment From Michael
Is there a resource to find park adjusted numbers for AAA players? I’m particularly interested in how much of a mirage Jesus Montero’s numbers are.

Neil Weinberg: I can’t think of the links off the top of my head, but google minor league park adjustments and you should get some sense of which parks are which. Also, you can take a peak at runs per game if you’re looking for a quick fix

Comment From Anton
I’m currently reading through the UZR primer to get a better understanding of how it works and then compare it to DRS. Which do you prefer and why?

Neil Weinberg: I think UZR a little more, just because DRS can sometimes produce some big outlier values, but honestly I look at them both almost equally.

Comment From Mike
When you update the Fangraphs library or make a post, is it possible to note it on the front page?

Neil Weinberg: As far as the blog posts, that’s probably not going to happen. When I make major updates to the glossary, I’ll drop a line in the main part of the site. I did wOBA last week and wRC+ is coming this week. I’ll probably announce them together or something.

Comment From Stephen
Neil, I’ll have an article up soon saying the odds of someone in a 2013 HR environment passing 73 is around 1 in 100.

Neil Weinberg: This is Stephen from Beyond the Box Score. So you can go read his methodology shortly.

Comment From MB
Why does DRS produce “big outlier values” moreso than UZR? And does DRS have a problem with shifting in the way that UZR does?

Neil Weinberg: I’m not entirely sure why DRS sometimes ends up with a +40 season. I don’t actually know for sure if it’s the wrong answer, it’s just the nature of the system. I know for a fact that UZR ignores shift plays but I’m not sure if DRS has started to incorporate them yet.

Comment From Jonas
Why are projected ERAs and FIPs different? As far as I understand, the gap between past ERA and FIP is mostly luck, and a bit of batted ball skill. So, does Steamer or ZiPS incorporate the batted ball skill when projecting ERA? If so, projected ERA is a better estimate for future ERA than projected FIP, right?

Neil Weinberg: This is a better question for Dan on Mondays. Probably a few different factors thrown in. I do not know for sure so I don’t want to give you wrong info about each system

Comment From Dan
What metrics should I be using to win bar arguments?

Neil Weinberg: The best way to win bets of this nature is probably BABIP. Find a guy with a .380 BABIP and bet your friends he’s going to get worse overall.

Comment From Tom
Hi Neil, excellent stuff so far. Asked this last week and you weren’t sure, but looks like the defensive component of catcher WAR is just rSB again this season? Didn’t it incorporate RPP in previous years? How does that work and what has happened to that stat? Maybe I have missed something, but seems like catcher WAR will therefore automatically be lower than previously. Any further ideas? Thanks

Neil Weinberg: I don’t have an official answer, but it appears as if this might simply update at the end of the season. I will have to check

Comment From Stephen
Neil, what stat are you most looking forward to informing America in general about? RE24? FIP-? WPA?

Neil Weinberg: I like explaining wOBA and FIP. Since I already did wOBA, I guess I’d have to say FIP. Although, I do have to say, it was very satisfying to build a wRC+ calculator the other day. A weird sense of accomplishment.

Comment From Doctor Doom
Follow up question on ERA- and FIP. Should we be concerned when a player like David Price has an increasing ERA – rate even though their FIP is still very good? What does it tell us about the pitcher.

Neil Weinberg: Typically, this isn’t something to worry about. The reasons a pitcher might do worse than their FIP are usually not things that are in a pitcher’s control and happen all of a sudden

Comment From Mike
DRS ignores shifts as well

Neil Weinberg: Thanks for confirming

Comment From Doctor Doom
Traditionally we’re taught that a high K rate is the best metric we can use to identify a the potential for a pitching prospect. What advanced metric do you think is the best metric to identify future major league success for pitchers? For hitters?

Neil Weinberg: I’m not the best prospect guy, but for a pitcher, I care about their K% and BB% together. We overrate guys who have stuff but no command. For hitters, K and BB and something like ISO? It can be hard to use minor league stats because the competition is very different.

Neil Weinberg: PS, I think I’m a slow chatter, but I can’t really tell. Apologies if that’s so, but I’ll chat for a long time to make up for it.

Comment From Ajay
Is there such thing as something like wRC+ that isn’t park adjusted? I want something scaled to 100 that only measures raw offensive output (maybe wOBA+?)

Neil Weinberg: You can create these stats on your own. Just do (STAT – LgAvg STAT) / LgAvg STAT

Comment From Andrew
How can I determine things like wOBA scale for my softball (read:beer) league? And what would be useful to keep track of in the book during the game for later use?

Neil Weinberg: Hmmm, I’m not sure exactly how you would go about this, because you would need long term data on run scoring in the league….but if you just do OPS, you’re probably fine. I’d track the different ways to get on base, how many bases your players advance on the typical hit, and if you’re ambitious, how often they turn a ball hit to them into an out

Comment From ben k
can you explain fip to me in a quick summary?

Neil Weinberg: FIP is an ERA estimator that uses only things a pitcher can truly control. So it takes K, BB, HBP, and HR and assumes the pitcher allows a league average BABIP with league average defense and sequencing on all balls in play.

Neil Weinberg: Pitchers have some control over sequencing and if balls in play drop for hits, but not very much. So FIP is usually a better measure of how they contributed to run prevention than RA9 or ERA

Comment From AC_Butcha_AC
Hey I have a question about historical positional adjustments on fangraphs. I noticed that the league wide pos. adj. seem to jump or fall in specific time frames. Of course with expansion there will be jumos and player strikes and teams switching leagues. But take a look at the positional adjustments for 2B for example. There seems to have happened something significant in 1990. The 5 years prior to 1990: 126, 125, 128, 129, 139. The 5 years starting with 1990: 60, 60, 55, 55, 64, 55. http://www.fangraphs.com/le… So even with positional fluidity it seems like FG has changed the positional adjustment for some reason. This is not only visible with 2B, but 1B and other positions. Mostly starting at round eras like 1950 or 1990. Has FG historically different positional adjustments that change from era to era?

Neil Weinberg: I will have to look into this.

Comment From Josh C
It seems like wRC+ overrates hitters with high slugging and underates hitters with high avg and obp but no slugging (jeter, ichiro). Do you agree with that?

Neil Weinberg: No. The entire point of wOBA or wRC+ is to give hitters exactly as much credit as they deserve for each action.

Comment From Doctor Doom
I’m sorry you’ve mentioned this three times…what’s sequencing?

Neil Weinberg: Great question.

Neil Weinberg: Sequencing is the order in which events happen. Let’s do an example.

Neil Weinberg: Here’s an inning:

Pitcher A: 1B, 1B, HR, out, out, out (3 runs)
Pitcher B: HR, 1B, 1B, out, out , out (1 run)

Neil Weinberg: There’s no evidence, to my knowledge, that there is any skill in terms of affecting the order in which those first three events happened. You allowed the same number and type of hit, but the order changes the run output. This will even out over a long period of time, but not in 100 or 200 innings, typically

Comment From Josh C
Is there any way to use sabermetrics with a teen baseball team? i think shifts, batting the best hitter 2nd, using good pitchers when guys are on base… etc stuff like that

Neil Weinberg: You can always use sabermetric principles, but you have to be careful of exactly what you’re doing. For example, the quality of defense is much worse and pitchers have less command. Stress getting on base over getting a hit, teach kids not to give away outs on the bases, etc.

Neil Weinberg: Keeping asking questions, going to take a one minute break and then I’ll keep going.

Comment From Dylan
Are IP under-rated by WAR because they save the bullpen?

Neil Weinberg: WAR gives pitchers more credit the more innings they pitch. And I haven’t seen any evidence that a pitcher saving the pen one day actually influences their performance in the future, but it’s super hard to prove either way. I think it’s fair to say that a starter on a team with a bad bullpen might have some incentive to stay on the mound longer, but I’m not sure there needs to be a bonus.

Comment From Cheap Beer Best Beer
Appreciate what you all do here. A couple questions. 1)Is there a way to make doing a minor league leader list easier? As of now I believe I need to click on a random minor league (say the CAL) and then select all leagues before I can compile minor league leaderboards. 2)Is there a way for us to get totals of lists. This is fantasy related but not a direct fantasy question. Is there a way to compile a list of players and have a total underneath?

Neil Weinberg: Best advice would be to bookmark this: http://www.fangraphs.com/mi…

And we don’t currently have the ability to total things up, it seems. Might have to do it yourself in Excel, unfortunately.

Comment From Matt
Struggling a bit wit understanding Reliever WAR – obviously the replacement level baseline for a reliever is higher, but I saw an older article mentioning that relief pitchers get some amount of credit for their leverage calculated into their WAR. Can you shed any light on how leverage factors into reliever WAR, or reference a good article that explains it? Thanks.

Neil Weinberg: Here are the basics. I’ll be overhauling the WAR section of the glossary, so I’ll pull this apart in the future. http://www.fangraphs.com/bl…

Comment From Anton
On baseball reference, pitchers have much higher WAR’s. Why is this?

Neil Weinberg: Specific pitchers, or all pitchers?

Neil Weinberg: We have different models of calculating pitcher-WAR, but I thought we allocated the same number of WAR to pitchers as a unit

Comment From Doctor Doom
Why doesn’t fangraphs utilize oWAR?

Neil Weinberg: Basically, oWAR and dWAR are confusing terms. oWAR tells you a player’s WAR based on their offensive value assuming their defense was average. I don’t see a real reason to do that.

WAR = batting + baserunning + position + fielding + league adj + replacement level

I don’t see a reason to say, this player has this WAR if you make certain terms = 0. Why not say, this player is worth this many runs above average on offense?

Comment From BravesfaninAL
Is there any point this year that the Braves give up on BJ Upton, contract be damned? The narrative so far has been “he’s doing better since the move to leadoff”, which I guess is true if you consider a still-terrible OBP of closer to .300 since the move an improvement over his OBP of closer to .275 before it.

Neil Weinberg: Seems unlikely. Braves have shown in the past (Uggla) that they will give players a long leash in terms of trying to get back to productivity.

Comment From Chris
How exactly are numbers park adjusted? Do you multiply specific numbers by the park factor, or is it divided? I’m confused as to how park factoring/league factoring works.

Neil Weinberg: We use the additive method. Let me walk you through how we do it for wRC+

Neil Weinberg: Mike Trout has a .428 wOBA.

Convert that to wRAA/PA and you get .0896.

We want to add that number to league average R/PA, which is .109.

Then we want to add in a run adjustment based on his home park. To do this, we do (MLB R/PA – (PF/100)*MLB R/PA).

So it ends up being .0896 + .109 + .00436

Then we divide this by the AL R/PA (about .11)

Then multiple by 100 and get 181

Neil Weinberg: Essentially, we want to determine how many runs to add to a players total per PA given the fact that he plays in a park that cuts offense by 4%. Hope that made sense!

Comment From Mike
Why does Fangraphs use UZR instead of DRS?

Neil Weinberg: I think the Daves like it a little better. We have both on the site, but use UZR for WAR.

Comment From Chris
That does make sense. Thank you!

Neil Weinberg: Good!

Comment From STiVo
There was lots of talk in today’s chat with Dave about how certain pitchers (example, Strasburg) might pitch worse from the stretch. Any stats that you know of that can be used to investigate this?

Neil Weinberg: You’d want to compare their performances based with men on base and with no one on base. Typically velocity doesn’t change much, but see if they’re allowing more hits/walks/power etc. Also check release point/location.

Comment From Tom
Great wRC+ walkthrough. Thanks!!

Neil Weinberg: Thanks. I’ll be updating the entry on it this week, so glad it was effective.

Comment From JC
Last Q&A you stated that on-base was 1.8 times more valuable than Slugging. How was that determined?!

Neil Weinberg: I think it’s based on comparing their influence on overall run scoring. I don’t know how it was originally determined, but you can imagine running a regression and seeing one point of OBP being twice as predictive of scoring than one point of SLG

Comment From MB
Is there any moderately easy conversion of Inside Edge defensive figures to run values?

Neil Weinberg: I don’t think so. At least I haven’t found one. You could probably do it with the raw inside edge data, but we only publish the counts and ranges (10-40%), which probably can’t get you there.

Neil Weinberg: Alright, going to go another 15 mins or so. If you have quick questions, fire them off as I pick out a few more from the queue

Comment From Mike
In a question regarding Headley, Dave Cameron just said that teams don’t put much value in third base defense (where most of Headley’s value comes from). Why do you think this is?

Neil Weinberg: Tradition. Even with all of the progress we’ve made in baseball analysis, lots of people can’t look at LF as a stop where you can be fast and a good defender because it’s supposed to be a slugger. Same is true, less so, for 3B

Comment From Dewey
Thank you Neil for this type of discussion. Was wondering if there’s a quick way to look at minor league performance filtered down to strength of opponent. We see a lot of silly video game numbers here and there, and I assume some of that has to do with quality of pitchers faced.

Neil Weinberg: I don’t think there’s a quick way, but if you just compare their performance to league average, you’re getting close to what you want

Comment From Guest
Regular question, if I may: Salazar, Hughes, or Masterson ROS?

Neil Weinberg: I literally cannot believe I am about to type this but…Hughes….

Comment From Anton
So should I just drop Wacha from my fantasy team?

Neil Weinberg: Redraft? Sure. Keeper, no way

Comment From Mike
How did you start working at FG and what did you do before this

Neil Weinberg: I started blogging a couple of year ago about the Tigers and stats and people started to share/read my stuff. Beyond The Box Score offered me a job, so did Gammons. I’ve been with them for a while and FG was looking to revamp their Glossary and Dave reached out to see if I’d be interested given my interest in saber-education.

Also a PhD student when I’m not a baseball writer

Comment From Andy
In the WAR calculation, you begin with wOBA and determine wRAA. This is corrected for park and league factors to give batting runs above average, and this is added to baserunning runs +/- average, defensive runs, positional, and so on. Then the total runs are used to determine WAR. My question is, where in this sequence does runs above average get converted into runs above replacement?

Neil Weinberg: Simple, you just add in replacement runs. It’s 20 per season, so it’s pro-rated based on games or PA

Comment From Jack
Injury aside, who do you see a good comp for in Wacha? I.E. A fasball changeup guy who seems to have figured it out at a younger age than most.

Neil Weinberg: Dave says James Shields…that might work?

Comment From Andy
For the questioner who asked about the derivation of 1.8 OBP + SLG, see http://www.insidethebook.co…

Comment From JC
What defensive metrics should I look at to determine which players should have a shift?

Neil Weinberg: Look at their batted ball profiles. Guys who hit GB or LD a lot to one side should be shifted

Comment From Kentavius
Who’s your biggest inspiration in the world of sabermetrics and also what are you studying?

Neil Weinberg: Inspiration seems like a heavy word? But I’ve read all of the main people for a long time and I like guys like Brian Kenny who have tried to make them more mainstream. And I’m studying political science

Comment From Costanza
how should we mentally apply park factors? it seems simplistic to multiply a player’s line by the p.f. to get the “result”. So how should we do it?

Neil Weinberg: My basic approach is to just mentally dial a guy’s numbers up or down. So if Tulo has a .430 wOBA, my brain tells me it’s more like a .410 or something. I’m going to try to build a rough conversion chart, but looking at wRC+ is just easier.

Comment From Kentavius
yea i guess “influence” would have been a better term

Neil Weinberg: I read Moneyball and FG mostly. Bill James and Tango’s work obviously too

Comment From Andy
For JC’s question about shifts, see a Max Weinberg article at this site a couple of weeks ago. He attempts to rank players according to how good a candidate they are for a shift, complete with an actual formula.

Comment From Doctor Doom
Thanks Neil! Best fangraphs chat I’ve ever been apart of. Keep up the good work!

Neil Weinberg: Appreciate that. I don’t know if I would say ‘best,’ though. I think this is a useful service, but I’m not the most entertaining of the bunch.

Comment From Hammerhead Hagan
Is Weaver now the 3rd best pitcher on the Angels, assuming that Wilson comes back fully healthy? Doesn’t seem to be missing as many bats as in the past. What are the best stats to evaulate him and the rest of that rotation?

Neil Weinberg: Richards is the best going right now. I’ve always been lower on Wilson and Weaver than most people. Heck I don’t think Skaggs is too far behind them

Neil Weinberg: Alright, I should probably wrap this up. If I didn’t answer your question , ask it again in the future. I’ll try to get to as many as I can every week.

Neil Weinberg: I’ll be updating the Library entry on wRC+ this week and will have a blog post about it and such up as well, probably Friday. Look for it at /Library or on our Twitter handle.

As always, I’m @NeilWeinberg44 on Twitter if you ever have questions about our data/site/metrics/etc

Neil Weinberg: See you all next week!