Comments on Basement Dwellers: What do we mean by replacement players?

Hi Richard,

The problem with using R/G inst...

2007-10-30T17:25:00.000-04:00

Hi Richard,

The problem with using R/G instead of R/PA is that I'm using absolute runs numbers... And those numbers don't take into account the full negative value of an out (the "inning killer" component that Tom Tango mentions in his pieces on run creation). Therefore, R/PA will tend to artificially up-weight individuals with low OBP's, and down-weight individuals with high OBP's. Here's a forum link where I wrestled through those issues..

With respect to the DH's...First, remember, I only considered a fielder's primary position. Giambi is a primary DH, so his fielding at 1B was not included (he was rated +0 on fielding vs. his position). I did, however, include a negative position fielding modifier for DH's, which did pull down the AL fielding numbers...Nevertheless, when I looked at these data before adding that modifier, and it still showed AL starters as being sub-par fielders. I can probably resurrect those unmodified data if you're interested.
-j

I wonder how much your results would vary if you m...

2007-10-30T17:16:00.000-04:00

I wonder how much your results would vary if you measured quality by R/PA rather than R/G.

I think that's where the variance between the leagues for the lower-ranked starters arises; lower-ranked starters in the NL are more likely to be pulled in a double-switch than their counterparts in the AL, and therefore accumulate fewer runs per game, even if they get the same rate of runs per plate appearance.

At a glance, the PA are much lower for those slices in the NL than in the AL; are the G played (which you don't list) also lower?

Secondly, the feature of AL starters being worse fielders: is it just that the top starters are more likely to be DHs than the lower ones, after all, DHs don't get injured as much as position players. You comment that the AL will look worse overall because of the DH, but surely there are more appearances by DHs in some slices than others?

I think you could address the second problem by ignoring fielding of players who are primarily DHs in the fielding measurement. Take Giambi as an example: he plays some 1B, but mostly DH and he wouldn't play regularly if it weren't for the DH; if he was in the NL, he wouldn't play anything like as much.

Incidentally, one thing I've noticed is that the NL puts a big premium on big-hitting 1Bs who are competent fielders (like Pujols), and so 1Bs gravitate to the NL if they can field well, and to the AL if they can't (because they can DH).

Sorry for the delay on the baselines article. It ...

2007-10-21T03:36:00.000-04:00

Sorry for the delay on the baselines article. It was set to go before I noticed something about using runs per game vs. runs per ab to calculate runs above average or runs above replacement. That's ended up pushing me back about two days, but the end result should be better and more interesting in the end. -j

First, position frequency didn't vary much across ...

2007-10-19T16:08:00.000-04:00

First, position frequency didn't vary much across slices, especially in the American League (in the NL, there was a spike in the number of catchers relative to other players in slices 5-8...the same was not true in the AL). So I don't think there's any particular bias here.

Second, I think that positional adjustments are a red herring when you're looking at offensive replacement level.

The purpose of a positional adjustment is to account for differences in defensive difficulties at a position. Players aren't born as "shortstops" or "second basemen." As Keppinger showed this season, you can stick a player at an unfamiliar position if you want. And if defense didn't matter, you would always make sure that you placed your best offensive players in the lineup no matter where you had to play them.

The reason you don't is that a corner outfielder, for example, would cost the team more in bad defense at shortstop than he provide the team in good offense. Therefore, any positional adjustments should really be applied to fielding performance, rather than offensive performance. This, in fact, is what I did in this study when you look at those fielding totals.

Basically, here's how I am inclined to assess player value:
[totalvalue] = [offense-vs-replacement] + [fielding-vs-average] + [positional fielding adjustment]

I'll also say that I think the idea of comparing offense at a particular position, like VORP does, is flawed because some positions are simply more talented than others. For example, several lines of evidence indicate that center field is the most difficult defense position to play on the ball field. And yet, center fielder tend to be ~league average hitters. This means that center fielders tend, on the whole, to be above average players. Therefore, if you base their positional adjustment on their offense, you're undervaluing them...especially relative to a weak-talent position like second base, who play an easier position while also not hitting as well!

I'll have more on this stuff in my next two player value pieces, starting tonight with baselines.
-j

Justin, what are your thoughts regarding the lack ...

2007-10-19T12:44:00.000-04:00

Justin, what are your thoughts regarding the lack of position context in studies such as this. A guy who hits .270/.330/.450 would be a horrible LF or 1B, but is perfectly acceptable at SS or at C.

If the Angels had a corner OF hitting .300/.400/.500 in Salt Lake, he's not really an option to unseat Cabrera at SS.

While I'm not sure how to approach it methodologically outside of a separate study by position or position group, I'm not sure how much insight we can truly get from an aggregate analysis.

Nice point. There actually is (at least) one dire...

2007-10-19T10:47:00.000-04:00

Nice point. There actually is (at least) one directly similar study that I'm aware of, by U.S. Patriot, which was done on '90-'93 data. He did things slightly differently, but found that the mean performance of players from the 14th slice onward was 73.8% of league average in the AL. In my study, individuals in the 13th slice onward (not starters or bench) in the AL performed at 68% of league average. If anything, you'd expect my number to be slightly higher, because it includes one fewer player per team as Patriot's.

So there's definitely some evidence for what you're suggesting. Pretty neat, actually--I was a bit confused as to why my estimate was higher than his. Your explanation seems pretty reasonable!
-j

Nice work. I wonder if a study was done using the ...

2007-10-19T09:45:00.000-04:00

Nice work. I wonder if a study was done using the same methodology for the time period of say 1984-1987 if the percentage of playing time for 'scrubs' would be the same then as it is now? Since one of the goals of statistical analysis is to be able to better identify players that can play, it would seem logical to assume that the percentage would be lower. For example, if a team has a whole at second base, shouldn't statistical analysis help identify and fix that problem more readily than simply plugging in guys until you stumble upon someone who can get the job done? If the percentage of playing time given to scrubs is the same now as it was then, does it mean that statistical analysis has failed in that area? Or maybe it just means the tools provided by statistical analysis aren't being used properly.