Breaking Down / Decoding FanGraphs

[DET Mr Malefic]

Mostly since the start of this baseball season (it may have started before then but I didn't notice until then), alot of posters here have been citing fangraphs as a great place to get information.

I've made my way to the site a few times and I tend to agree.

However, there is alot of abbreviations and language there that I simply do not understand, as someone who is not deeply steeped in the heavy saber language. Furthermore, they really ought to be ashamed of themselves for their flimsy glossary, which explains very little of what is on the site.

Worse yet, many whole categories they do not explain, but link to lengthy articles wherein the information on what you're trying to find may or may not be buried inside.

So I'm going to use this thread for myself, along with others who may be like me, to ask those who are well versed on the numbers on this site for help. I'd like some of this stuff decoded. I'm going to ask for alot, and I know that for none of you guys is this kind of stuff a job, so I'm not looking for quick answers. I also don't really want or need links to lengthy texts explaining the mathematic basis of each number (unless requested in a follow-up question). Basically, I want/need a general idea of what the abbreviation stands for, what is actually being measured, and what generally constitutes Exceptional/Good/Average/Poor/Horrible performance.

With the preface written, I'd like explanations for the following:


Under the "Batters" tab

* - Under the "advanced" tab there is a statistic called "Spd". It's fairly obvious that this is a measure of speed, but what does the number listed mean? I don't even know if its about base stealing or base running or fielding or what.

* - Under the same tab, there's wRC. I'm assuming this is some play on the "Runs Created" statistic, but I don't know that for certain. No idea what it means.

* - Same tab, wRAA. Not a clue.

* - Same tab, wOBA. I'm assuming this is some play on OBP.....but again, I don't know for sure, don't know what it means.

* - Under the "win probability" tab, there's a stat "WPA". For this one, I know that this is the win probability added tab. I know what this stat means in terms of what its specifically measuring, but I have a hard time interpreting it. Based on my knowledge of the statistic, it would seem that this is as close a measure as there is to measuring "clutchiness". Or moreover, a "key play maker" statistic. Is that the correct way to interpret it? Or is a more general performance statistic that I for whatever reason cannot properly interpret naturally? I'm also assuming that the -WPA is the cumulative number of negative plays and the +WPA is the cumulative number of positive plays with WPA being the sum of these two. Correct?

* - Regarding leverage index, what is the theoretical highest and lowest possible number? Just from looking at the number and the various players it is clear to me that 1.50 represents very high leverage, but I have no anchor point upon which to say with confidence that a certain number is any higher or lower.

* - I literally understand none of the numbers under the pitch value tab. I understand that the abbreviations stand for the various pitches, but I have no idea what the "w" stands for prefixing the pitches on the right side columns, nor do I understand what those numbers mean. At all.

* - Much of the same can be said about the plate discipline tab. It's all greek, including the headers.

* - Under the "value" tab, I understand that for hitting and fielding those numbers are indicative of how good a player is, but what exactly ARE those numbers. To me seeing "Hitting - 12.3" is telling me nothing. 12.3 on a scale of what? What is the 12.3? Is that the number of wins theoretically added? The number of positive plays per week? What? Same for fielding. What does "replacement" mean? And why is the number different for each player? What about "positional"? Is that the average for that player's position? I'm assuming dollars is the theoretical amount that the player should be paid for their performance this year. I understand WAR and RAR completely, no explanation needed there.



I started this thread with the intent of asking all the questions I had, but I was/am on my lunch break from work and now I have to get back to work. I'll add on to this thread with the pitching and fielding numbers that confuse me when I get home in a few hours, or maybe tomorrow. But this should start it off.

[Scottwood]

If Lee or someone else doesn't answer your questions before the end of tonight, I'll break it all down for you. Batting, pitching, fielding, etc.

I can't right now, though. But, you will get an answer at some point if no one else is able too.

[cruzer1]

The Glossary | FanGraphs Baseball


The Glossary

Click on any of the stats for more detailed information.
Advanced

K/9 (strikeouts per 9 innings): The average of how many batters a pitcher strikes out per 9 innings pitched.
Win Probability

WE (win expectancy): The percent chance a particular team will win based on the score, inning, outs, runners on base, and the run environment.

LI (leverage index): A measure of how important a particular situation is in a baseball game depending on the inning, score, outs, and number of players on base, created by Tom Tango.

WPA (win probability added): WPA is the difference in win expectancy (WE) between the start of the play and the end of the play. That difference is then credited/debited to the batter and the pitcher. Over the course of the season, each players’ WPA for individual plays is added up to get his season total WPA.

RE24 (runs above average by the 24 base/out states): RE24 is the difference in run expectancy (RE) between the start of the play and the end of the play. That difference is then credited/debited to the batter and the pitcher. Over the course of the season, each players’ RE24 for individual plays is added up to get his season total RE24.

REW (run expectancy wins): REW is the same as RE24, except it has been converted to a wins scale.

+WPA (win advancement): The amount of positive wins a player contributed to his team, including only the plays where he increased his team’s win expectancy.

-WPA (loss advancement): The amount of negative wins a player contributed to his team, including only the plays where he decreased his team’s win expectancy.

pLI: A player’s average LI for all game events.

phLI: A batter’s average LI in only pinch hit events.

gmLI: A pitcher’s average LI when he enters the game.

inLI: A pitcher’s average LI at the start of each inning.

exLI: A pitcher’s average LI when exiting the game.

WPA/LI (context neutral wins / game state linear weights): How many wins a player contributes to his team with the Leverage Index aspect removed, invented by Tom Tango.

Clutch: A measurement of how much better or worse a player does in high leverage situations than he would have done in a context neutral environment.
Pitch Types

FB - fastball
SL - slider
CT - cutter
CB - curveball
CH - changeup
SF - split-fingered
KN - knuckleball
XX - unidentified
PO - pitch out
Plate Discipline

O-Swing% (outside swing percentage): The percentage of pitches a batter swings at outside the strike zone.

F-Strike% (first pitch strike percentage): The percentage of plate appearances (for batters) or batters faced (for pitchers) that the first pitch was a strike. This includes anytime that the count after the first pitch was 0-1, or anytime the ball was put into play on the first pitch of a plate appearance.

Fielding

DG (defensive games): The number of outs made by an average fielder at his position given the exact distribution of balls in play for that player divided by the number of outs an average player at that position makes per game.

exO (expected outs): The number of outs plus reached base errors that would be made by an average fielder given the distribution of balls in play while that fielder was on the field.

ARM (outfield arm runs): Outfielder’s get credit (plus or minus) depending on what the runners do on a hit or a fly ball out. A runner can stay put, advance, or get thrown out. A fielder will get credit not only if he throws out more than his share of runners, but also if he keeps more than his share of runners from advancing extra bases.

DPR (double play runs): The number of runs above or below average a fielder is, based on the number double plays versus the number forces at second they get, as compared to an average fielder at that position, given the speed and location of the ball and the handedness of the batter.

RngR (range runs): The number of runs above or below average a fielder is, determined by how the fielder is able to get to balls hit in his vicinity.

ErrR (error runs): The number of runs above or below average a fielder is, determined by the number of errors he makes as compared to an average fielder at that position given the same distribution of balls in play.

UZR (ultimate zone rating): The number of runs above or below average a fielder is in both range runs, outfield arm runs, double play runs and error runs combined.

UZR/150 (ultimate zone rate per 150 games): The number of runs above or below average a fielder is, per 150 defensive games.

Win Values

Read Dave Cameron’s Seven Part Series: Explaining Win Values

Part 1 - Batting
Part 2 - Fielding
Part 3 - Positional
Part 4 - Replacement
Part 5 - Converting Runs to Wins
Part 6 - Dollars
Part 7 - Additional Information

Read Dave Cameron’s Seven Part Series: Pitching Win Values Explained

Part 1 - Introduction
Part 2 - FIP
Part 3 - Replacement
Part 4 - Run Environments
Part 5 - Converting Runs to Wins
Part 6 - Park Adjustments
Part 7 - Calculations

[DaYooperASBDT]

Maybe Tyrus is right after all.

But thanks for all the info !!!!

[billfer]

wOBA is something to pay attention to. It is a stat that synthesizes a player's offensive contributions into one number without some of the inherent flaws of something like OPS (which is adding 2 numbers with different denominators - easy to calculate but limited).

Using empirical data run values are calculated for various offensive outcomes (1b, 2b, 3b, hr, bb, ibb, roe, hbp, sb, cs) and then applied to a player's actual line. You add it all up and then divide by total plate appearances. The numbers scale to OBP so it is easy to interpret what is a good wOBA. The league average is usually around .333 or so (varies slightly by year).

The other thing you can do is then figure the runs a player contributes compared to an average player by taking the difference of a player's wOBA and the league wOBA and multiplying it by total plate appearances and dividing by 1.15.

For more info: http://www.insidethebook.com/woba.shtml

[Shelton]

I really like wOBA, but I would love for them to come up with something that takes into account baserunning. BP's equivalent baserunning runs is pretty nice, but I want a fangraphs version that is incorporated into their value stats. Obviously speed is taken into account by the doubles and triples. But once they are on the bases, it doesn't seem to be taken into account.

[billfer]

Originally Posted by Shelton

I really like wOBA, but I would love for them to come up with something that takes into account baserunning. BP's equivalent baserunning runs is pretty nice, but I want a fangraphs version that is incorporated into their value stats. Obviously speed is taken into account by the doubles and triples. But once they are on the bases, it doesn't seem to be taken into account.

At the rate fangraphs is expanding their offerings, it's only a matter of time.

[tiger337]

Weighted On Base Average(woBA), Weighted Runs Above Average (wRAA) and Weighed Runs Created (wRC) are all based on linear weights. Based on thousands of games of data, it has been determined that the average single is worth .48 runs, the average double is worth .78 runs, triple 1.04, homer 1.40, walk 0.31, etc. Based on those values, wRAA is a player's runs produced above average.

wOBA is the rate statistic version of wRAA. It is like OPS but it uses the weights given above. The reason why it's called wOBA is because it has the same scale as OBA or OBP. So, if you see a player with a .380 wOBA, you know he is really good. If you see a .280 wOBA, you know the player is really bad.

wRC is Weighted Runs Created. It is also based on the same weights given above. instead of being runs above average, it is total runs the player contributed. 100 wRC is very good.

[tiger337]

Originally Posted by Shelton

I really like wOBA, but I would love for them to come up with something that takes into account baserunning. BP's equivalent baserunning runs is pretty nice, but I want a fangraphs version that is incorporated into their value stats. Obviously speed is taken into account by the doubles and triples. But once they are on the bases, it doesn't seem to be taken into account.

The fan graphs wOBA does included SB and CS. You are right that it would be nice if the final WAR stat included a base running component similar to the BP Equivalent Base Running stat. It will eventually.

[Shelton]

Originally Posted by billfer

At the rate fangraphs is expanding their offerings, it's only a matter of time.

Agreed. Once they get that stat incorporated, there will be no stopping them. I would also like them to incorporate the projections that they publish into a future value stat going into each season based on 150 games.

BP still has a monopoly on standings predictions, and I think fangraphs could do a better job with their resources.

[tiger337]

Originally Posted by cruzer1

Win Values

Read Dave Cameron’s Seven Part Series: Explaining Win Values

Part 1 - Batting
Part 2 - Fielding
Part 3 - Positional
Part 4 - Replacement
Part 5 - Converting Runs to Wins
Part 6 - Dollars
Part 7 - Additional Information

Read Dave Cameron’s Seven Part Series: Pitching Win Values Explained

Part 1 - Introduction
Part 2 - FIP
Part 3 - Replacement
Part 4 - Run Environments
Part 5 - Converting Runs to Wins
Part 6 - Park Adjustments
Part 7 - Calculations

yes, those are excellent. The hitting Win Value series is particularly easy to follow.

[Shelton]

Originally Posted by tiger337

The fan graphs wOBA does included SB and CS. You are right that it would be nice if the final WAR stat included a base running component similar to the BP Equivalent Base Running stat. It will eventually.

I wasn't aware that it included SB and CS. That's good. I assume it still doesn't include things like first to third on a single, and the other things that eqBRR includes.

I would also love to see a value stat normalized for playing time. It would make comparing Maggs and Josh Anderson much easier. Something like a value/150 or whatever.

[DET Mr Malefic]

Cruzer, I saw that glossary link, but as I said in my original post, they only give explanations for some of the stats (none of which I listed above, or if I did, my questions were mainly based around the interpretations of the stats), or they have those articles, wherein they do not have the quick two-four sentence explanations given for the rest of the stats, but lengthy articles that delve into more than I really need to know. I basically just want to know what I'm seeing when I read this stuff and how to interpret it......I don't necessarily need to know the whole background or the theory behind it.

To put it into an analogy.......I just want to learn how to drive the car and to be able to tell when something is wrong with it and point it out to the mechanics. Less interested in how the engine works or how they generate power to the taillights.

[Scottwood]

Originally Posted by billfer

At the rate fangraphs is expanding their offerings, it's only a matter of time.

fangraphs is definitely a daily read for me. Fascinating stuff.

[lesgoblu02]

I feel so stupid right now.

[tiger337]

Value Stats:

Batting - Runs Above Average (wRAA) adjusted for ballpark

Fielding - Ultimate Zone Rating or Runs Saved Above Average

Replacement Value - replacement level adjustment - 20 Runs / 600 PA.

Positional Adjustment - Points added or subtracted based on difficulty of position

RAR - Runs Above Replacement rather than average. It's the sum of the first four columns.

WAR - RAR converted to Wins

Dollars - How much money the player is worth based on WAR.

[pyrotigers]

Speed Score | FanGraphs Baseball

[tiger337]

The Speed Score at FanGraphs is not very good. The Equivalent Base Running Runs stat (EqBRR) at Baseball Prospectus is much better. It tells how many runs above average a player's base running is worth. It is based in SB, CS, taking the extra base on hits (such as first to third on a single, moving up on fly balls and groundouts, etc.

Baseball Prospectus | Statistics | Custom Statistics Reports: Baserunning

[RatkoVarda]

I like fangraphs, but even they fall into the internet's trap of making DEFINITIVE PROCLOMATIONS! that turn out to be incorrect.

The Edwin Jackson/Matt Joyce trade | FanGraphs Baseball

[billfer]

Originally Posted by RatkoVarda

I like fangraphs, but even they fall into the internet's trap of making DEFINITIVE PROCLOMATIONS! that turn out to be incorrect.

The Edwin Jackson/Matt Joyce trade | FanGraphs Baseball

Why is that an internet trap?

[RatkoVarda]

The general "trap" of the internet is like this:
The anonymity of the internet allows people to makes all sorts of ridiculous (or obscene or racist or whatever) posts. And even though Cameron is not really anonymous, I think there is pressure from the general tone of the internet to make strong, definitive proclamations (like "a ridiculous bas trade") to keep up with the internet Joneses. It is this "trap" leads to a lot of unnecessary hyperbole.

[tiger337]

Originally Posted by RatkoVarda

I like fangraphs, but even they fall into the internet's trap of making DEFINITIVE PROCLOMATIONS! that turn out to be incorrect.

The Edwin Jackson/Matt Joyce trade | FanGraphs Baseball

That happens everywhere, not just the internet. I see newspaper writers, radio talk show guys, etc doing it all the time. That article should have been worded differently but Dave Cameron is generally a very good writer and researcher. I don't think his article was ridiculous either, just the part where he called it a "ridiculously bad trade". After that, he made some points which were reasonable at the time he wrote it.

[john doe]

Originally Posted by lesgoblu02

I feel so stupid right now.

And from now on if you want to express an opinion about music or just want to enjoy you're favorite CD, you must study and memorize this first. Music theory - Wikipedia, the free encyclopedia

[billfer]

Originally Posted by tiger337

That happens everywhere, not just the internet. I see newspaper writers, radio talk show guys, etc doing it all the time. That article should have been worded differently but Dave Cameron is generally a very good writer and researcher. I don't think his article was ridiculous either, just the part where he called it a "ridiculously bad trade". After that, he made some points which were reasonable at the time he wrote it.

This was my thought as well. He had a strong opinion about the trade. I don't think the internet had anything to do with it.

He was wrong about the trade, as was I. the analysis he offered was solid.

[84 Lives!!!]

Originally Posted by tiger337

The Speed Score at FanGraphs is not very good. The Equivalent Base Running Runs stat (EqBRR) at Baseball Prospectus is much better. It tells how many runs above average a player's base running is worth. It is based in SB, CS, taking the extra base on hits (such as first to third on a single, moving up on fly balls and groundouts, etc...

It's funny that the leaders for the Tigers in this stat are Gerald Laird & Carlos Guillen!!!

[DET Mr Malefic]

Originally Posted by tiger337

Value Stats:

Batting - Runs Above Average (wRAA) adjusted for ballpark

Fielding - Ultimate Zone Rating or Runs Saved Above Average

Replacement Value - replacement level adjustment - 20 Runs / 600 PA.

Positional Adjustment - Points added or subtracted based on difficulty of position

RAR - Runs Above Replacement rather than average. It's the sum of the first four columns.

WAR - RAR converted to Wins

Dollars - How much money the player is worth based on WAR.

Thanks, this was a huge post for me.

One more thing:

Is WAR the same as "WARP", and if so, which version of WARP is it equivalent to?

Also, while I know that it cannot be done directly (or at least I think it can't), is it theoretically the case that you should be able to add up the WAR number for all of the players and come roughly +/- 3 games to the number of overall team wins?

[DET Mr Malefic]

Originally Posted by 84 Lives!!!

It's funny that the leaders for the Tigers in this stat are Gerald Laird & Carlos Guillen!!!

Honestly that passes the eyeball test to me. Guillen has been one of the Tigers best baserunners in my observation since he's been on the team, and when Laird first came to Detroit the first thing I noticed when I watched him play live for the first time was how much he hustles (and doesn't get cheated) on the basepaths. I think if the numbers say that they're the two best baserunners, that pretty well matches the eyeball test. For me anyway. Although the "eyeball test" tells me that Granderson is better than both of them.

[tiger337]

Originally Posted by DET Mr Malefic

Is WAR the same as "WARP", and if so, which version of WARP is it equivalent to?

It's similar to WARP (any of the WARP versions) in terms of what it does and how it is interpreted. WAR is probably more accurate because the fielding portion of the measure (UZR) is better than what Baseball Prospectus uses. The hitting portions of the WAR and WARP are probably equally as good.

Also, while I know that it cannot be done directly (or at least I think it can't), is it theoretically the case that you should be able to add up the WAR number for all of the players and come roughly +/- 3 games to the number of overall team wins?

It is not designed to add up to actual team wins. Each player is evaluated separately according to how many runs/wins he would produce playing on an average team. I haven't checked it but I suspect the WAR might not add up as closely to team wins if it's an extremely good hitting or poor hitting team. It should come close for most teams though.