Friday, June 27, 2008

Theory on Replacing Dunn and Griffey


I've actually been chewing on this for quite a while, so I thought I'd get my thoughts down on paper, so to speak. Basically, what I'm trying to do is to figure out just how difficult it would be to replace the production of Adam Dunn. Now, to do so, I'm actually going to try to replace the aggregate production of Dunn and Griffey for 2008. Not surprisingly, I've picked two of my favorites. I'll replace Dunn in left with Matt Murton and Griffey in right with Jayson Werth.

Now, for simplicity sake, I'm going to keep this very theoretical. I'm not saying Werth and Murton are easily obtainable, but rather just trying to determine the feasibility of replacing two offensive minded outfielders who play poor defense with two sterling defensive outfielders who are solid at the plate. You could plug in any number of outfielders (i.e. Ryan Spilborghs and Austin Kearns, etc) in the analysis who fit the profile.


To get an accurate gauge on the total value of a player's contribution to his team, I'd say you have to measure his performance in the currency of the game: Runs. So, I tried to take a look at the runs created on offense and runs saved on defense of all 4 of the aforementioned players.

DEFENSE


It's tough to do, because there are no generally accepted defensive metrics, so there is likely to be disagreement on which one to use. That said, I chose Baseball Prospectus's Rate2, because it is a rate stat that normalizes for playing time, which is necessary given that Murton and Werth haven't played 162 games in a season.

BP defines it as: "A way to look at the fielder's rate of production, equal to 100 plus the number of runs above or below average this fielder is per 100 games. A player with a rate of 110 is 10 runs above average per 100 games, a player with an 87 is 13 runs below average per 100 games, etc."


So, I took the career defensive performance of Dunn (91) and Murton (112) in leftfield and extrapolated it out over 162 games. Based on his career performance, Dunn is 14.6 runs BELOW average in leftfield, while Murton is 19.4 Runs ABOVE average. I did the same for Griffey (94) and Werth (111) in right, where Griffey is 9.7 runs BELOW average, while Werth is 17.8 runs ABOVE average.

Maybe Dunn's improved defensive performance in 2008 is legit, but for now I'll work under the assumption that a larger sample size will bring about a regression to the mean.

In summary, by going from Dunn in left and Griffey in right to Murton in left and Werth in right the Reds improve defensively by roughly 61 runs.


OFFENSE


Again, I'm not sure which would be the most appropriate stat to boil down a player's offensive contribution to Runs. However, it's a bit tricky to compare part time players like Murton/Werth to full-time guys like Griffey/Dunn. Accordingly, I went with Batting Runs Above Average (BRAA), as it is measured on the same basis as Rate2 (i.e. a player's performance above average).

However, I had to extrapolate it out over equivalent levels of playing time for comparison's sake. So, I chose 650 plate appearances.

For Dunn, I went with his 2007 level of performance (.264/.386/.554), as it seems typical of his performance. In 2007, Dunn posted a BRAA of 39. When extrapolated out over 650 PAs, Dunn posts a BRAA of 40.1.

For Murton, I went with his 2006 level of performance (.297/.365/.444), because I think that's a pretty fair approximation of what he would do in 2008. His power numbers may even be better in GABP, but I think that's a fair estimate. Anyway, in 2006 Murton posted a BRAA of 9, which gives a BRAA of 11.5 when extrapolated out over 650 PAs.

For Griffey, I went with his 2007 level of performance, though I suspect that is being a bit generous. In 2007, Griffey had a BRAA of 25 and when extrapolated out over 650 PAs it gives him a BRAA of 26.1.


For Jayson Werth, I blended his 2007 and 2008 levels of performance together. I'm not quite sure what his performance level will be, but I suspect it falls somewhere between 2007 (.298/.404/.459) and 2008 (.262/.337/.497). So, Werth's combined BRAA in 2007 (16) and 2008 (6) is 22. When that is extrapolated out over 650 PAs, Werth posts a BRAA of 30.6.

In summary, over 650 PAs Dunn and Griffey would create 66 BRAA, while Murton and Werth would create 42 BRAA. So, Dunn/Griffey would have a 24.1 run advantage over Murton/Werth on offense.

WARP3


Also, we can look at a cumulative stat like WARP3.

Here is a BP definition of WARP: "Wins Above Replacement Player, level 1. The number of wins this player contributed, above what a replacement level hitter, fielder, and pitcher would have done, with adjustments only for within the season. It should be noted that a team which is at replacement level in all three of batting, pitching, and fielding will be an extraordinarily bad team, on the order of 20-25 wins in a 162-game season."

WARP3 is an updated version of WARP, which includes a few additional factors to increase the accuracy of the stat.

In essence, WARP3 is a rate stat that encompasses offense and defense. So, it should suit our purposes. I went with the WARP3 that's Adjusted for All-Time.


In 2007, Dunn had a WARP3 of 5.8, while Griffey had a 6.4 WARP3. Taken together you get 12.2.

In 2006, Murton had a WARP3 of 6.0. And, Werth had a WARP3 of 4.8 in 2007 and so far has a WARP3 of 3.9 in 2008, so let's say he's at 4.4. Taken together, you'd get 10.4.

So, Dunn/Griffey would provide an advantage of 1.8 Wins Above Replacement Players over Murton/Werth.

Admittedly, I don't know the ins-and-outs of WARP3, so I fail to see
why Murton posted the following:

2005: .321/.386/.521 with a WARP3 of 1.7.
2006: .297/.365/.444 with a WARP3 of 6.0.
2007: .281/.352/.438 with a WARP3 of 2.7.

If I had to guess, I'd infer that it largely came down to defense.


In 2005, Murton played a poor leftfield, posting a Rate2 of only 97. So, despite stellar offensive numbers, he was below average
defensively.
In 2006, Murton played a stellar leftfield, posting a Rate2 of 114. So, even though he had less impressive offensive numbers, he was stellar defensively.
In 2007, Murton had solid offensive numbers and played an exceptional leftfield (Rate2 of 129), but spent the majority of the time in rightfield (Rate2 of 102), so the defensive impact was lower.

So, I suppose his 2006 season combined solid
offense with tremendous defense to give him a very high WARP3.

SUMMARY

From my admittedly rather rough estimates, Dunn/Griffey would provide 24 more offensive runs, but Murton/Werth would save 61 more runs on defense. From these rough estimates, it looks like a 37 run advantage by going with the Murton/Werth tandem.

On a WARP3 basis, it looks like Dunn/Griffey provide an advantage of 1.8 Wins Above Replacement Players over Murton/Werth. Perhaps Murton's WARP3 wouldn't be so high, but I doubt Griffey's would be either.


Going into the analysis, I really didn't know how I was going to tackle it or how it was going to turn out, but I didn't attempt to jigger it in my favor. I know that there is a significant subjective element to it and that it is a rough take (at best), but I did attempt to base the approximated inputs on realistic estimates. And, while I'm sure there is a significant +/- error built into the calculations, I'm not so sure that going from Dunn/Griffey to Murton/Werth wouldn't be a lateral move or at least a fairly minimal downgrade. I suspect that Werth/Murton could do a very solid job of replacing the aggregate production of Dunn/Griffey for a fraction of the cost. Even if Dunn and Griffey would be better in 2009, would they be so much better to justify the additional money and the opportunity costs?

To make a long story short, I can't really conceive of a way to replace Dunn's production with just one player. However, I think you can certainly do it with 2 players. While you could, of course, make the argument to keep Dunn and just replace Griffey, I think we might be better off letting both of them go, which would maximize both our cash savings and compensatory draft picks. From where I sit, it's always better to be both "leaner and meaner" and very strong on the defensive side of the game.

While I certainly don't offer this as indisputable proof that Murton/Werth would be the better tandem, it might speak to the feasibility of replacing Dunn without bringing about the end of the organization as we know it. Their may be problems with the methodology or inputs in this analysis and we could argue all day about the appropriate metrics to be used, but I suspect that the underlying theory is a sound one.

The path to the promised land is paved with great defense and it's time for the Reds to take the first step on that journey.

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