Win Values Explained: Part Three
Continuing on with our series explaining win values, today, we get back to positional adjustments. We spent a lot of time talking about them the last few weeks, so if you haven’t read those articles, I’d suggest catching up first. A basic summary of the need for position adjustments follows below, for those who want a short version.
Since we started off with wRAA (which is offensive runs above or below league average) and UZR (which is defensive runs above or below league average at a specific position), we need to calibrate the scale to make up for the fact that some positions are significantly harder to play than others. It is much harder to find a +5 SS than it is to find a +5 2B, and we need to represent that in the Win Value system. That’s what the position adjustments are there for.
Traditionally, offensive position adjustments have been popular, which aligns the positions by adjusting on the basis of the difference in offensive runs. However, due to the variability in offensive performance from year to year, that can lead to miscalculations, such as believing that an NL 2B and an NL SS were equal in 2008 because they had the same batting line. Clearly, shortstops are better defenders than second baseman, and we have to reflect this in their value.
That’s why we prefer a defensive position adjustment. The position adjustment scale we use is as follows:
Catcher: +12.5 runs (all are per 162 defensive games)
First Base: -12.5 runs
Second Base: +2.5 runs
Third Base: +2.5 runs
Shortstop: +7.5 runs
Left Field: -7.5 runs
Center Field: +2.5 runs
Right Field: -7.5 runs
Designated Hitter: -17.5 runs
To read more about how these were arrived at, check out these threads at The Book blog.
The position adjustments are then scaled to match the games played at each position for a particular player. This way, players that spend time at multiple positions get a hybrid adjustment based on their playing time at the respective spots.
Once you add the wRAA, UZR, and position adjustment together, you have the sum of a player’s value above or below league average. If we used Chase Utley as an example, he gets 37.1 wRAA, 19.2 UZR, and 2.3 Position Adjustment for a total of +58.6 runs. In 2008, Chase Utley was 58.6 runs better than a league average player. If you want to start handing out credit for the World Series title in Philly, give him the most, because that’s outstanding.
However, now we have value above or below average, but what is average worth? Clearly, it’s worth more than zero, as teams pay significant cash for league average players every winter, and a team full of league average players would win 81 games and generate positive revenue for their franchise. But, in terms of dollar values, we don’t have a fixed baseline for what a league average player is paid.
However, you know what we do have a fixed baseline for? The league minimum player. MLB has set $400,000 as the least any player can get paid, so we know that a player who is completely replaceable is worth $400,000. That makes replacement level a good target to calculate value off of. So, this afternoon, we’ll talk about replacement level and how that is defined.
Dave is the Managing Editor of FanGraphs.
I would like to coin a new phrase, combining two words that are not often used togeter – “baseball nerd.” We are all baseball nerds. This is great stuff.
I am new to viewing this site and it has lot of great information.
Just to understand, the UZR and the positional values are the defensive metrics. You can add these together to value a players defense.
Adding wRAA and replacement value (not yet discussed) are the offensive metrics. You can add these values together to value a players offense.
Adding them all together gives you a total picture of a players value. Are these assumptions right?
Also, off topic, do you plan on providing righty/lefty stats in the future. I see you provide this info in graph form. If not, could you atleast add the actual numerical stat to these graphs.
Lastly, do you plan on changing the current wOBA listed on your site to one that would adjust for park and league factors.
Thank you.
I wouldn’t necessarily phrase it that way. wRAA is an offensive metric, UZR is a defensive metric. The position adjustment, while based on historical defensive performance, is a neutral metric, as is replacement level.
For instance, you could add wRAA + Position + Replacement together and get our version of VORP, which is an offensive metric.
Adding all four components together gives you a player’s value. You could create other permutations of the components to measure other things – offensive or defenisve runs above replacement position, offensive or defensive runs above average, etc…
I understood all three parts, as I use something similar myself. I was just wondering how you come up with the replacement value.
NVM my last comment. I didn’t read the last sentence. I’m a dummy.
Does Fangraphs have a section where league average stats are listed?
There’s another reason for using replacement level. In my mind, it’s much more important than finding a good baseline for salary. It has to do with playing time.
In essence, it’s easier to be ten runs above average in half a season than an entire season. The standard deviation of performance is greater when the sample size is smaller, so the full-season figure is more impressive than the half-season figure. However, if you just used WAA, you wouldn’t know the difference.
Replacement level fixes this problem by factoring in playing time.
Of course, you may have already said this in Part Four. I haven’t read that yet. Can’t keep up!
Yep, that’s exactly right, and covered in part four. I’ll try to slow down so you old guys can keek up…
Huh?
(said in an old guy’s voice, one who’s hard of hearing. In case the joke wasn’t obvious.)
So if I add up all the position adjustments I get 0 with no DH and -17.5 with a DH. If 14/30 of the teams are AL and 14/30 games are with DH that weights to an average position adjustment of -8.2 per 150 games. That’s -8.8 per 162. If I go to the team page, I see the average team positional adjustment is -12.4. I was expecting those numbers to be equal.
Further, I was expecting each team’s positional adjustment to be equal to -17.5 * % Games in AL Stadiums * (162/150) since each team fields the same positionss, but that’s not the case. In fact, there’s quite a bit of variation among the team totals: AL ranges from -16 to -27 and NL ranges from -1 to -10. A quick glance suggests that these numbers are before any player movement (Teixeira listed with Braves and Angels).
What am I missing here?
Hmm, I may have I figured it out: I think fielders get a full games positional adjustment whether they play the whole game or just an inning. So if the positional adjustments are meant to be per 150 full games rather than 150 average games, the positional adjustments are overstated.
Dave,
Love your stuff here and on USSM. Just to clarify for my own sanity, using the positional adjustments you listed, would catching (+12.5 runs) be considered statistically the most difficult position or do catchers get the most credit for their defense? I’m sure I’m just over thinking this…
Chris,
More of the former. The way Tango discusses positional adjustments is called Runs Over Willie, for Willie Bloomquist, or other similar players who can play everywhere. If you put Willie at SS, then the average SS would save +7.5 more runs per 162 games. If you placed Willie at 1B, then the average 1B would cost his team -12.5 runs more per 162 games than Willie.
With regards to catching, this suggests that if you place a guy like Willie behind the plate, even an average fielding catcher will save +12.5 more runs than Willie, which is +1.25 wins. Catching is a specialized skill, so this basically says that even someone with average catching skills is over one win more valuable behind the plate than the regular utility guy you can throw back there.
“It is much harder to find a +5 SS than it is to find a +5 2B, and we need to represent that in the Win Value system.” This statement also applies to right fielders (SS) and left fielders (2B). The pool of candidates is smaller for right field; to play there you need to be able to throw. This is not reflected in the adjustments.
I don’t get why guys like Albert Pujols are in the negatives for positional adjustment but people like Hanley are positive?
Pujols = 1B
Hanley = SS
Its a lot easier to find a 1B than a SS. Its a lot easier to play 1B than SS.
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One thing that I don’t understand is why some players do not receive the full value for their positional adjustment. My guess is that it’s based off of playing time. Am I right?
Nice post you got here. It would be great to read more concerning this theme.
Small point, but you write: “Clearly, shortstops are better defenders than second baseman, and we have to reflect this in their value.” I’d think that’s just as clearly not always the case (or, as someone at BBTF might say, “Derek Jeter says ‘hi.'”
So you might want to rephrase to say what you mean. (Or maybe I shouldn’t have read the explanation on a break from grading papers.)
What is the positional adjustment for pitchers as hitters? +75 or something?