tag:blogger.com,1999:blog-23241716.post116063369262169907..comments2023-07-09T11:23:36.355-04:00Comments on On Baseball & The Reds: Player Value, Part 2c: Offense - Positional Adjustmentsjinazhttp://www.blogger.com/profile/07697776280178146413noreply@blogger.comBlogger22125tag:blogger.com,1999:blog-23241716.post-88632110143149717872007-10-30T17:50:00.000-04:002007-10-30T17:50:00.000-04:00The skills that are important at some positions co...The skills that are important at some positions correlate better with hitting well than others. So a 2B might be absolutely worse than a CF, but it's more unusual to find 2B-type skills in a competent hitter than CF-type skills, because CF-skills correlate better with hitting than 2B skills.<BR/><BR/>The point is that it's not just about how absolutely difficult a particular position is to play to a major-league competent level; it's also how good the pool of hitters is that can do that, ie the pool of CFs isn't that big, but it's deep; the pool of 2Bs might be bigger, but it's shallower.Richard Gadsdenhttps://www.blogger.com/profile/10545595590359552775noreply@blogger.comtag:blogger.com,1999:blog-23241716.post-36807264448304225942007-10-30T17:02:00.000-04:002007-10-30T17:02:00.000-04:00Hi Tango,Thanks for your post in my series--I like...Hi Tango,<BR/><BR/>Thanks for your post in my series--I like the phrase "hitting or fielding level of replacement players." Nice way to put it.<BR/><BR/>I also recently did a replacement study, and found much the same results as you did with respect to fielding. -jjinazhttps://www.blogger.com/profile/07697776280178146413noreply@blogger.comtag:blogger.com,1999:blog-23241716.post-56103033286224902652007-10-30T15:54:00.000-04:002007-10-30T15:54:00.000-04:00It is important to keep repeating that there is no...It is important to keep repeating that there is no replacement level hitting or replacement level fielding. Just replacement level players. You can say hitting level of replacement level players, and fielding level of replacement level players. And, as has been shown on my site, the fielding level of those players is very close to the average for their position.Tangotigerhttps://www.blogger.com/profile/11864323151591103655noreply@blogger.comtag:blogger.com,1999:blog-23241716.post-62390021091770303312007-10-30T00:27:00.000-04:002007-10-30T00:27:00.000-04:00I was sort of lazy and just used Chris Dial's esti...I was sort of lazy and just used Chris Dial's estimate of ~1440 defensive innings per team per year as the denominator, and player innings at a position as the numerator. I should probably go and check that number to make sure it's a reasonable estimate these days, but I just trusted him...and it seems to work.<BR/><BR/>As for DH's....eek. I fortunately am mostly interested in National League (namely, the Reds), so I haven't had to deal with that. I don't have a great solution either. Maybe if you have games started as a DH, you can then just estimate 9 innings per game started to get at least some idea. DH's are so problematic anyway, since it's hard to know what to use for a position adjustment for them... -jjinazhttps://www.blogger.com/profile/07697776280178146413noreply@blogger.comtag:blogger.com,1999:blog-23241716.post-27102147735479163812007-10-29T21:25:00.000-04:002007-10-29T21:25:00.000-04:00How are you pro-rating the innings? If a CF is +1...How are you pro-rating the innings? If a CF is +10 over a full season, are you defining full season as 162*9 innings? Per 150 games? Something else? How are you handling DH "innings"?Anonymousnoreply@blogger.comtag:blogger.com,1999:blog-23241716.post-2329584460545263472007-10-29T15:58:00.000-04:002007-10-29T15:58:00.000-04:00Hey Sky,Do you mean position multipliers on the of...Hey Sky,<BR/><BR/>Do you mean position multipliers on the offensive numbers? I'm not.<BR/><BR/>I'm just calculating offense vs. league-wide replacement hitting (which I'm defining as 73% of league average).<BR/><BR/>I'm then adding in fielding vs. average at a position. And then adding in a pro-rated (by defensive innings) position adjustment for runs (I'm using Tango's numbers). If players play multiple positions, I pro-rate the position adjustment for each position and then sum 'em up. :)<BR/>-jjinazhttps://www.blogger.com/profile/07697776280178146413noreply@blogger.comtag:blogger.com,1999:blog-23241716.post-50858797895234993252007-10-29T15:49:00.000-04:002007-10-29T15:49:00.000-04:00Justin, so what are you using as your positional m...Justin, so what are you using as your positional multipliers?<BR/><BR/>Your line in one of these comments that "replacement level fielding IS league-average fielding" resonated with me. I always thought of it as "replacement-level players are average fielders and crappy hitters", but having replacement level players be both replacement level hitters and fielders sits better. Nice.<BR/><BR/>To those who don't like the fact that different players would perform differently at different positions, it doesn't really matter for what Justin's trying to measure, which is value. Adam Dunn actually played LF. Even if he was a slick fielder and would be a great SS, that's not where he played. He was 20 runs worse than the average LF, who's 10 runs less valuable than the typical shortstop. Value comes from out-performing the alternative and the skills of the typical alternative don't depend on Dunn's actual ability as a SS.<BR/><BR/>If you're not trying to measure value -- say, you want to know how much Adam Dunn would help your team as a shortstop if you signed him as a free agent -- then yes, you definitely want to know how Adam Dunn will play shortstop. Scouting is important. Tango's Fan Scouting Report says that his instincts, first step, and hands are dreadful, likely making him a worse SS than LF.Anonymousnoreply@blogger.comtag:blogger.com,1999:blog-23241716.post-4183100580042106752007-10-24T19:51:00.000-04:002007-10-24T19:51:00.000-04:00Rick,1. The reason that you can't use the mean in ...Rick,<BR/><BR/>1. The reason that you can't use the mean in my example at first base is that it would result in a lower standard (and thus a greater boost) for first basemen than we're already using with offensive disparities. Right now 1B's are compared against 119% of league average. Using the mean of all NL players would put them at just about 100% of league average, which would mean that 1B's would be considered more valuable than ever (if anything, they should be less valuable, because there is more competition at that position than any other defensive position).<BR/><BR/>What we're interested is, as you said, an indication of who the top X possible players are at their position. Which is why, if using one year of data, I'd probably try to construct some sort of regressed rate-based ranking within each position's theoretical pool, remove the top 60 players or so (1 starter + 1 bench), and then look at the next set of players to find replacement level. Might be neat to try at some point.<BR/><BR/>2. I think it's an error to consider offense and defense separately for each player. A very strong defensive player can be an above average player despite bad offense (e.g. Adam Everett). And vice versa (e.g. Hanley Ramirez, Derek Jeter). You can't just think about it as what "defense" can you freely get, because that defense is always going to come coupled with offense in your replacement player. You have to think about as what <I>player</I> could you freely find, and what his total value would be (or, what his typical offense and typical defense will be, which is the approach I took in my replacement study). <BR/><BR/>Tom Tango often says that there's no such thing as replacement-level offense or replacement-level defense. Instead, there are replacement <I>players</I>, and that's what we're after. I think he's right. That's why, <I>if</I> we can get an accurate depiction of position value, it probably would be best to scrounge up as many top position-neutral value players as you could (regardless of position), and then stick them into positions as best you can to maximize the leverage of each players' defensive skills. It might mean that some players will play out of their "natural" position, but that's certainly something that happens in real life...and at some point, the [runs scored] + [runs allowed] makes that a defensive or offensive loss worthwhile.<BR/><BR/>3. I expect you're right that the defensive spectrum is both oversimplified and non-linear, probably in a variety of ways. It is the case that players generally move down the defensive spectrum, and not up it, so it might be hard to test your directionality idea with a good, minimally biased sample in both directions. <BR/><BR/>One thing that might be tractable would be to down-weight extreme values (log-scale?) within each position and then re-do Tango's study. Thinking about it, though, I wonder if that would just make the positional disparity estimates even more conservative, since it's the extreme guys who are (probably) likely to have the bigger-than-usual changes.<BR/><BR/>The goal, to me, is to get the best estimate I can of player value. It's always going to be an estimate, as we can never control or account for everything. But I still think that we can get a pretty good idea using the approach I'm advocating. And as better estimates of position value disparities come out, I'll gladly adopt those new values in my work.<BR/>-jjinazhttps://www.blogger.com/profile/07697776280178146413noreply@blogger.comtag:blogger.com,1999:blog-23241716.post-72125344002338263072007-10-24T19:09:00.000-04:002007-10-24T19:09:00.000-04:00I think I am arguing for the hybrid type model you...I think I am arguing for the hybrid type model you begin to describe at the end. What I don't understand is this assertion:<BR/><BR/>"The question, once we have the pools, would be how to then look for replacement level. We couldn't use the mean, because adding weaker offensive positions to the pool of talent available to poor defensive positions lower that standard--and that's not what we're after"<BR/><BR/>Why not? Why are we afraid to lower the offensive threshold. It seems to me that that is in fact reality. The fact is that offense is offense. The only reason that we require less offense at SS is because it is difficult to find a player who's defense at SS does not offset his offensive value. <BR/><BR/>Thus, in LF, the pool of available offensive talent is enormous precisely because the defensive requirement is so low. You can find a lot more people who provide a .800 OPS and play a good LF than you can who do the same at SS. However, because the standard for entry is so low, it requires somebody of significant offensive value to break in to our magic top 30 (or 60).<BR/><BR/>It is precisely this pressure which encourages us to push guys as far up the defensive spectrum as possible.<BR/><BR/>I think the real trick is to consider replacement offensive and defensive performance separately and not together. Then you define replacement as that level of performance which places you at the top X players at the position. And unless you put in an artifical floor for defensive ability, then you must consider all position players in the calculus at each position.<BR/><BR/>So the offensive replacement value is the same at every position. However, the defensive replacement value swings quite a bit. The problem with Dunn at SS (or Ryan Braun at 3B) is that he's so far below what you can freely get defensively that it negates a great deal of his positive offensive value. The problem with a guy like Neifi Perez is that his crappy offense negates all of his defensive value (and more).<BR/><BR/>So basically, I do think you have the right basic equation. The issue is that offensive value is constant regardless of position and defensive value varies by position. This matters once we get in to financial valuation.<BR/><BR/>- An aside -<BR/>The last part of my hypothesis is that the defensive spectrum isn't linear at the extremes. That is to say, if you take the best CF and put him at 1B, he's not equally better in terms of raw runs than the average 1B than he is compared to the average CF. In CF, the spread of possible defensive contributions is wider and thus differences between ability more valuable. So a guy who is +30 in CF might only be worth +35 at 1B, not the +43 Tango's model would suggest.<BR/><BR/>- End Aside-<BR/><BR/>For example let's call Dunn a +80 offensive guy and a -25 position neutral defensive guy. At SS he's worth just +51 where as in LF he's worth +59. If the linear model works, you can just accumulate the most valuable position-neutral guys you can get your hands on and it won't matter where you stick them defensively. But this strikes me (perhaps incorrectly) as intuitively wrong.<BR/><BR/>However, what if Dunn (-25) isn't just a -21 in LF and -29 at SS, but is actually -40 at SS. Also, what if our SS (+5) isn't just +1 at SS and +9 in LF, but is only +6 in LF. I fear that this average technique is flattening out a non-linear spectrum and thus minizing the true effect of good defense at the "tough positions", underestimating the increased influence of moving left in the spectrum and overestimating the influence of moving right.<BR/><BR/>For example. Pujols is +30 at 1B (+22 pos neutral) and Ichiro is +33 in CF (+38 pos) neutral. I don't think it's likely that Pujols would be +17 in CF (I think he'd be lower) than Ichrio would be +46 at 1B (I think he'd be lower). Perhaps it's as simple as the fact that the skill sets difference we've touched on comes in to play. <BR/><BR/>Where players have moved positions it's been in those cases where they happened to have skills which translated. However, it's possible that these players are not representative of the general sets of abilities held by their position mates. So while Chone Figgins, Pujols, or Soriano can (and have) switched positions, that was largely due to their possession of two only partially related skill sets. Scott Rolen and Juan Pierre may possess both sets or at least at the level of those who have switched.<BR/><BR/>In general, moves to the left on the spectrum would generally result in bigger losses and moves to the right result in smaller gains.<BR/><BR/>Which leads me to hypothesize that the defense conversion scale cannot have two way arrows between each stop but needs to have a different scale for moving in either direction. Using a defense neutral measurement based on a methodology like Tango used incorrectly flattens out these curves due to a biased sample predisposed to such adaptability leaving a general difficulty measurement that cannot be generally applied.RedsManRickhttps://www.blogger.com/profile/12585911809169263164noreply@blogger.comtag:blogger.com,1999:blog-23241716.post-24530284937548031362007-10-24T16:58:00.000-04:002007-10-24T16:58:00.000-04:00Rick,Most of what you wrote is in complete agreeme...Rick,<BR/><BR/>Most of what you wrote is in complete agreement with what I wrote in the original post under the first explanation for why offense varies by position: there is a smaller talent pool of players that can play the most difficult/unique positions, which means that there's less competition for offensive excellence. Which I argued is almost certainly correct, and must be (a part of) why offense varies across positions. So I think we're in complete agreement that this is an important difference when comparing players across positions.<BR/><BR/>Now, clearly, if a player is part of a select group of individuals (e.g. someone who can competently play center field), he is worth more to a team than someone who can only competently play first base, because "everyone" can play first base. The question is, how <I>much</I> more valuable is he?.<BR/><BR/>The traditional approach, which I think(?) you're advocating, is to compare individuals strictly to others within their own position. So replacement level at a position is 73% of hitters at that position, and league average fielding at that position. This way, you're only comparing a player against his opposing numbers on other teams, which theoretically sets all players on a level playing field. <BR/><BR/>The problem I see with doing that is that measuring players who are currently playing a given position does not give you a complete picture of the pool of talent that could play that position. For example, Troy Tulowitzki would play a badass second base, and would be among the best hitters at that position. But he's excluded from that pool because he's good enough to play another, more demanding position. This can, and demonstrably does, result in talent level differences among positions, like the fact that the "standard" for both hitting and fielding are both lower at second base than center field, according to Tango's data.<BR/><BR/>The approach I'm arguing for takes the position that the reason for there being smaller talent pools that can play one position vs. another is that some positions are harder. Therefore, it tries to quantify how much harder, in terms of runs, some positions are vs. the other. The argument is that you <I>could</I> take average-fielding first baseman and stick him at shortstop...but if you did that, what would be the cost that you'd incur on defense? That cost seems to me to be a good estimate of the value of a shortstop over a first baseman. Therefore, player value = [offense vs. lg-replacement] + [defense vs. replacement=average] + [position difficulty adjustment]<BR/><BR/>I'm still not seeing any problems with that approach, except that it's hard to quantify position difficulty. In theory, at least, it makes sense to me.<BR/><BR/>Thinking about it, there might be a third approach that makes some sense: instead of using offensive averages at a position, use offensive averages among players that could theoretically play that position. We can use the defensive spectrum derived from Tango's data or the Fans' data to do this, which makes it: C-CF-SS-2B-3B-RF-LF-1B-DH.<BR/><BR/>Then, for each position, we could quantify the production of those players that qualify for that position. So catchers and probably center fielders would be compared only against one another. First basemen would be compared against everyone except DH's. DH's would be compared to everyone. <BR/><BR/>We might even be able to use the Fans Scouting report to further hone down those cutoffs: e.g. only those players with at least decent throwing arms would be eligible for third base, but range isn't so much an issue...<BR/><BR/>The question, once we have the pools, would be how to then look for replacement level. We couldn't use the mean, because adding weaker offensive positions to the pool of talent available to poor defensive positions lower that standard--and that's not what we're after. But we could try to do some kind of quality-based sorting (maybe regressed rates or something?), and then look at the 60th or so individuals (e.g. what you get after removing 2 players per team for that position).<BR/><BR/>I wonder what those data would look like. I have a feeling that it'd be too much of a penalty for first basemen, but I'm not sure. I might try to do this someday, but it wouldn't be easy.<BR/>-jjinazhttps://www.blogger.com/profile/07697776280178146413noreply@blogger.comtag:blogger.com,1999:blog-23241716.post-40212960738909088012007-10-24T15:36:00.000-04:002007-10-24T15:36:00.000-04:00Justin, I think that perhaps I'm thinking more in ...Justin, I think that perhaps I'm thinking more in terms of some sort of real limit on available talent by position.<BR/><BR/>If we were to limit the possible SS to just those people who could play it at -20 runs (as managers essentially do in practice), that would limit the pool of potential SS, excluding somebody like Adam Dunn. I would suggest that as we move up the chain, the average offensive production from the true available pool decreases.<BR/><BR/>This sort of selection naturally occurs on the offensive side, as no player who OPS's less than say, .600 is given a full-time job -- because we "know" that no amount of defense can make up the difference between the overall value of a free available lesser defender who's better with the stick. <BR/><BR/>So, out of the 1,000 theoretical possible SS (including Adam Dunn), only 100 of them can field the position within 20 runs of average. Any person who you want to count as a true replacement must match that bare minimum defensive threshold. <BR/><BR/>Where this really matters is when we use the concept of replacement to look at market pricing. So while the overall run value might be able to be neutralized by position, the size of the available talent pool varies. <BR/><BR/>When we go looking for a replacement SS, we aren't considering Jesse Gutierrez or Eric Hinske --- even if they might in reality have a greater total run value at SS than Juan Castro. So as we consider what replacement level looks like, we should restrain our description to that population from which we would actually draw a specific replacement.<BR/><BR/>Which begs the question, are we artificially limiting our pool of potential players at each position to our detriment? Or rather, is the system really running efficiently with players positioned such as to maximize their overall run production value?<BR/><BR/>I think your point in the last paragraph is perhaps the key to the whole series. A run is a run. The goal is simply to accumulate more than the opponent and you can achieve that both by creating them and preventing them.RedsManRickhttps://www.blogger.com/profile/12585911809169263164noreply@blogger.comtag:blogger.com,1999:blog-23241716.post-67075388201687927942007-10-24T14:17:00.000-04:002007-10-24T14:17:00.000-04:00Hi Rick,Lots of great points in there.A few commen...Hi Rick,<BR/><BR/>Lots of great points in there.<BR/><BR/>A few comments:<BR/><BR/>* First, offensive disparities among positions are indeed larger than Tango's numbers, and sometimes are much larger. For a rough estimate, 1 r/g (r/27 outs) is worth about 15 runs a season.<BR/><BR/>Reasons for this are many, but here's a few ideas:<BR/><BR/>1. Position talent varies more than we probably typically think it does. I really think this may be a huge part of it. After all, the most talented (offensive+defensive skill) players usually start at either shortstop or center field and then move "down" the defensive spectrum as they move up through the minors, right? That is generally going to mean that the most-bestest talented players will be those that stick at shortstop and center field.<BR/><BR/>2. There is probably some selection bias in Tango's data, because it can only collect information on players that are actually allowed to move positions. The estimated difference between left field and first base, for example, may be the result of tracking how 1B/LF's do at those positions, and then how utility infielders do when plugged in at first base (or, how SS/3B's do, and then how 1B/3B's do). Those are very different groups of players, which adds some uncertainty between the numbers... especially because, as you mentioned, the skills required to do well at a position do differ among positions. <BR/><BR/>When it comes to actually trying to evaluate these skill differences, I think the fan scouting report might turn out to be our best available tool. Something to add to my list of things to look at..<BR/><BR/>FWIW, depending on the groups you select, Tango found that there is evidence that all outfield positions are substantially harder to play than infield positions. I don't buy that, and neither does he, which is why he ultimately went with the spectrum I cited.<BR/><BR/>Nevertheless, I still don't see that measuring offensive disparity really tells us what we want to know when making position adjustments. The fielding-based adjustments seem much closer to the mark, because they're really trying to measure what is actually different among positions, even if the results are more conservative.<BR/><BR/>* Second, I do think that a lot of GM's (and fans) don't value offense vs. defense as well as they could. I think many seem to weight offense higher in some positions, but defense higher in other positions. That's why one of the first things I tried to do in this series was illustrate that a run saved is just as valuable as a run scored. And if that is the case, then we should be willing to accept any combination of offense and defense that provides above-average value. That goes for left field as much as it goes for shortstop. The adage of being willing to sacrifice defense in corner positions for the sake of offense doesn't make sense--except that you better-leverage poor defensive players by putting them in positions where they won't get as many chances (and Tango did try to account for variation in chances in his data). <BR/>-jjinazhttps://www.blogger.com/profile/07697776280178146413noreply@blogger.comtag:blogger.com,1999:blog-23241716.post-85079637828956210492007-10-24T11:44:00.000-04:002007-10-24T11:44:00.000-04:00Justin, I think I used poor phrasing to make my po...Justin, I think I used poor phrasing to make my point. It's not that defense is more variable. It's that the offensive distribution is substantially more right skewed. Given a group of equal defensively talented players, the variation of offensive of talent as measured by is quite spread - a greater standard deviation in terms of run production. Given a group of equal offensive players, the run production distribution is tighter.<BR/><BR/>We can assess this pretty easily. What is the average run production differential in offensive production between a 1B and CF? What is the average run production in defensive production between a 1B and CF (13 runs according to Tango)?<BR/><BR/>Without seeing the numbers (your posted offensive and defensive numbers aren't on the same scale), I'm going to assume for the sake of this argument that the offensive difference is greater.<BR/><BR/>Offensive production is offensive production regardless of what spot in the batting order it comes from. That is to say, each PA is created equal. You can't "hide" a batter to minimize the effect of their offensive ability in the same way you can hide a poor defensive player. At most you're looking at a batting order difference that results in about 10% fewer at bats for the poor hitter. For fielders, there's not only an issue of the quantity of opportunities, but the quality of them. Surely, the talent required to field a ball in LF or 1B is different than at SS.<BR/><BR/>Secondly, the defensive baseline for playing the field in the major leagues is much much lower than for hitting. The bare minimum amount of both offensive and defensive production has been established over decades. There is some bare minimum level of talent that non-DH, non-pitcher must have. Guys like Jack Cust and John McDonald are at either end of this spectrum. If Cust was an even worse fielder (or if he had to play the field every day) or if McDonald was any worse with the bat, they wouldn't be viable major leaguers because their lacking skill set would too greatly offset their strong one -- and their strong one is essentially as good as is possible.<BR/><BR/>Put another way, there are many 1,000s of players who have the overall position-neutral defensive talent necessary to play in the majors. There are less than 500 people who can hit well enough to be in the majors. This is in part why the DH was created. There are few Frank Thomases or Edgar Martinezes and many many Juan Castros and Neifi Perezes.<BR/><BR/>I guess my problem is coming up because of this -- given the relatively small difference between positions, hasn't the market overvalued defensive production?<BR/><BR/>It would seem that given that league average offensive production is harder to come by than league average defensive production, that we should see crappier defense than we do. Are we putting up with way too many crappy hitting guys who aren't substantially awesome defenders? Why would we tolerate a .700 OPS SS with a great glove but never tolerate a .700 OPS LF regardless of his glove, when the defensive difference due to position is just 8 runs?<BR/><BR/>It would seem that one of 3 things is going on:<BR/><BR/>1.) I'm over-estimating the spread of offensive production. That is an 8 run spread is more valuable than I think it is.<BR/>2.) A lot of GMs (ie. nearly all) are overvaluing defensive production relative to offense.<BR/>3.) The translations suggested by Tango understate the positional differences.<BR/><BR/>Sorry for the rambling post. I realize this isn't really a direct response to my earlier comments and your response to those -- just thinking out loud.RedsManRickhttps://www.blogger.com/profile/12585911809169263164noreply@blogger.comtag:blogger.com,1999:blog-23241716.post-83660247103744450892007-10-24T00:21:00.000-04:002007-10-24T00:21:00.000-04:00Hi Rick,I don't know...do you think there's more v...Hi Rick,<BR/><BR/>I don't know...do you think there's more variation around these means that there is around the offensive means at each position? <BR/><BR/>In other words, the traditional approach is to use an 87% adjustment for shortstops because they, on average, hit that much worse than average. But there's obviously a huge amount of variation around that number, because some shortstops are comparable with just about any hitter in baseball, while others are among the worst hitters in baseball. So is that approach any better in terms of applying means to individual players? I'm not sure that it is. And yet, folks seem comfortable using those numbers as estimates of position value. ... despite the fact that it doesn't really measure what we're trying to measure in positional adjustments (differences in defensive value among positions).<BR/><BR/>As for the issue of how good a first baseman could be...I don't know. Albert Pujols is the best defensive first baseman right now, and is a heck of an athlete. I'm not sure that he wouldn't be a decent shortstop. <BR/><BR/>And Griffey was certainly an awful center fielder. Do you think he'd be much better than average at first? Somehow I doubt it.<BR/><BR/>Again, I'm not arguing that these numbers are perfect. But I think that this approach is the approach we should take in adjusting player value by position, at least as much as possible (catchers and DH's are a significant problem...). If we don't use those numbers, what is the alternative? I see two: make no adjustment, which is obviously unhelpful and ignores what are clearly differences in value among positions. Or, to do an offense-based adjustment, which seems completely inappropriate to me given what we know about relative position talent. <BR/><BR/>Maybe there's an approach that falls somewhere in between, but I don't have a good idea of how to objectively come to that point. We could figure the average runs difference based on offensive disparities, and then average that difference with numbers from Tango and the Fans scouting report.. That might be a worthwhile approach to take (sort of a best-and-worst of both worlds approach), but I'm trying to avoid sticking my neck out too far for now until I've at least mastered what folks have done to this point..<BR/>-jjinazhttps://www.blogger.com/profile/07697776280178146413noreply@blogger.comtag:blogger.com,1999:blog-23241716.post-12042831875020333782007-10-23T19:05:00.000-04:002007-10-23T19:05:00.000-04:00Perhaps useless was a bit blunt. (and please don'...Perhaps useless was a bit blunt. (and please don't confuse my criticism of that point with my love of this series you're doing)<BR/><BR/>I'm just not sure how you can use those numbers in a valuation process due to the extreme amount of variation around those means. While the average is meaningful as an average, the amount of variation is such that to apply it to any specific player simply adds to much error. It's certianly useful in understanding the relative "talent" as you put it, but not as useful in player valuation, which is really the heart of your series.<BR/><BR/>Presumably, (with all due caution) you would take this to the point where using an adjustment such as Tom Tango's, we can say simply that Dunn is a -22 runs defender (-18 + -4). Thus, we can also compare him to all offensive players and create a position-neutral player to player valuation system.<BR/><BR/>I am curious, is that scale comparable to the plus/minus one you've used? Especially at the extremes, we see cases where great firstbaseman would be good SS and bad CF would be just mediocre 1B -- and neither of those seem very intuitive.RedsManRickhttps://www.blogger.com/profile/12585911809169263164noreply@blogger.comtag:blogger.com,1999:blog-23241716.post-50482844946657892422007-10-23T18:32:00.000-04:002007-10-23T18:32:00.000-04:00Hi Dan,Thanks--like I said, it's not my idea, is j...Hi Dan,<BR/><BR/>Thanks--like I said, it's not my idea, is just what I've come to agree works best. Overall, perhaps it doesn't make a huge difference. But at shortstop and center field, in particular, it's important.<BR/><BR/>Regarding your point about replacement level...I see how it might be confusing. Replacement level fielding IS league-average fielding. The reason I shy away from calling it replacement level fielding, however, is that BPro's replacement-level fielding stats use a baseline that is much lower than average. And I don't want what I'm doing to be confused with what they do, because the data I've seen indicate that their definition of replacement level fielding is not meaningful (it actually puts the total value of a replacement player much lower than anything the resembles reality...that's one of the issues that you run into with WARP).<BR/><BR/>Thanks also for the typo--I'll fix when I get a sec. I'm always omitting words...apparently I go back and edit too much, even on my proofreading pass(es).<BR/>-jjinazhttps://www.blogger.com/profile/07697776280178146413noreply@blogger.comtag:blogger.com,1999:blog-23241716.post-73570278756912359752007-10-23T18:19:00.000-04:002007-10-23T18:19:00.000-04:00Rick,Well, needless to say, I completely disagree ...Rick,<BR/><BR/>Well, needless to say, I completely disagree that these values are "virtually useless." Can they be improved upon? Sure, of course they can. If nothing else, it might be nice to give right- and left-handed throwers their own spectra (that somehow inter-relate), since left-handed throwers are so restricted with respect to where they can play. But I still feel that this approach is a step forward for our ability to rate players.<BR/><BR/>The fact that you can find players that violate the typical value differences is not a massive problem for this method. For one thing, defensive stats are about twice as volatile as hitting stats, and therefore we're always dealing with substantial uncertainty when looking at any particular player. <BR/><BR/>Furthermore, on some level, I think we have to reward teams for playing players in the positions where they will perform best. What we--or at least I--want to do with a positional adjustment in terms of player value is account for the typical differences in defensive value of a player at one position versus others. After all, from the perspective of offense, a hit is a hit and a run is a run. It's defense where position matters, and an average fielding left fielder is not worth as much as an average fielding shortstop because it's easier to be an average fielding left fielders than an average fielding shortstop (this analysis says the difference averages at around 8 runs).<BR/><BR/>Does it mean that every player will gain or lose 8 runs per season on defense when they move between these two positions? Of course not. But that's the typical change we've seen, and therefore the typical difference in defensive value of a shortstop vs. a left fielder.<BR/><BR/>To me, even with its uncertainties, this approach is far more preferable than the use of position adjustments based on offensive disparities. It recognizes that there may be differences in talent levels across positions, and seems to me to more closely recognize what actually is different about players at different positions. -jjinazhttps://www.blogger.com/profile/07697776280178146413noreply@blogger.comtag:blogger.com,1999:blog-23241716.post-14005231869552974672007-10-23T18:17:00.000-04:002007-10-23T18:17:00.000-04:00one last thing, the bold font in the essay is miss...one last thing, the bold font in the essay is missing an "are" before the word "inadequate"danhttps://www.blogger.com/profile/11635462248852203362noreply@blogger.comtag:blogger.com,1999:blog-23241716.post-36652591403728047682007-10-23T18:16:00.000-04:002007-10-23T18:16:00.000-04:00I dont recall ever seeing an argument against Wool...I dont recall ever seeing an argument against Woolner/BP's VORP positional adjustment that was this clear-cut. Justin, this evaluation of widely used principles is incredible. <BR/><BR/>A minor gripe, however, is that the UZR and fan's fielding data is measured against average. In previous posts you said two things:<BR/>1) Comparing to a replacement player gives better insight into the value of the player than comparing to average<BR/><BR/>2)Replacement level fielding is relatively similar to league-average fielding. Even if it is the same as the average, the name should at least be called a baseline.<BR/><BR/>Overall,great jobdanhttps://www.blogger.com/profile/11635462248852203362noreply@blogger.comtag:blogger.com,1999:blog-23241716.post-33912095687990245622007-10-23T16:37:00.000-04:002007-10-23T16:37:00.000-04:00That defensive translation stuff is very interesti...That defensive translation stuff is very interesting, but I wonder how translatable it really is. Averages can be useful but can also be very misleading for comparisons of either broad or skewed distributions.<BR/><BR/>The issue of skill set difference is discussed, but not incorporated. I think it's extremely problematic. Adam Dunn converts to a better SS than Hanley Ramirez. Also, BJ Upton rated as a minus 2B and a plus CF.<BR/><BR/>Between skill set types, real learning curve, defense ability regression due to age, etc. this has a long long way to go. Definitely interesting stuff -- but virtually useless at this point.RedsManRickhttps://www.blogger.com/profile/12585911809169263164noreply@blogger.comtag:blogger.com,1999:blog-23241716.post-51219244364650002472007-10-23T13:37:00.000-04:002007-10-23T13:37:00.000-04:00On average, after he learned his position, yes, ou...On average, after he learned his position, yes, our best estimate is that he'd play ~3 runs below average defense at third base.<BR/><BR/>Mileage will vary, of course, depending on the various skills of the player (arm strength, reaction rate, sprint speed, hands, etc). But that's the estimated average change in defensive ability, based on Tango's study.<BR/>-jjinazhttps://www.blogger.com/profile/07697776280178146413noreply@blogger.comtag:blogger.com,1999:blog-23241716.post-5943836637583709552007-10-23T13:31:00.000-04:002007-10-23T13:31:00.000-04:00That is a thought-provoking concept. I want to mak...That is a thought-provoking concept. I want to make sure I understand this correctly. If you move a league average LF to 3B, then he would field 3B at 3 runs below the league-average third baseman? Is this correct? Thanks.texasdavehttps://www.blogger.com/profile/17215541522980498371noreply@blogger.com