rLF - A Quick Stat



With all of the discussion about the value of defense recently, I decided to create a very rough and quick statistic to show its value in a way that even the casual fan can understand. I termed the stat "rLF" and the first test subject is everyone’s favorite third baseman, Adrian Beltre.

Adrian Beltre has often been a source of controversy between the Statheads and the casual fan. Although no one denies he is a good player, there is an argument as to whether or not he is worth his "value" – that is, the 11ish million he makes per year because of his (seemingly) low production offensively.

While much of the controversy lies in his basic stats, such as his batting average, slugging, HR’s, etc. – and I would argue his offensive stats themselves if you equate for his bad luck are already worth the contract – the other part of his game that is underappreciated is his defense.

As Jeff and others have pointed out of late, defense is not only underappreciated, it is also not hard to find. An ~average defender can be found in the minors for next to nothing. Finding a good defensive fielder with a good bat may be more difficult, but "average" is fairly easy to find, and you won’t have to trade the farm to get it.

Despite his error today, Adrian Beltre appears to have both. He has a good bat that has been unlucky of late, and a glove that may not have been the best in the American league last year (Screw You Brandon Inge) but was easily in the top 3. According to everyone that has watched him play, he is at least a 5 < X < 15 above average run saver with his glove. For the sake of argument, let’s split the difference and say that, with his glove, he prevents 10 runs from scoring on average.

As Jeff often says, a run saved is as important as a run scored. So what I decided to do was create a quick stat that shows the value of those runs prevented by converting it into offensive numbers.

Why offensive numbers? Because those are the statistics that make the most sense to the average fan. If you are trying to explain how much his defense positively affects his value, it would be far easier to say what Adrian Beltre would need to HIT to equal the same production if he was just an average defender.

I used average as the baseline because an average defender is not difficult to find. There may be a better way, but I’m not a stats guru and I don’t have a lot of time to spend on this… ever.

The Method

I entered Beltre’s basic stats into a spreadsheet (BB, Singles, Doubles, Triples, HRs). To find out the runs created by Beltre I used THT’s RC (Runs Created) stat. It was quick and easy, though there may be a better way to calculate these values. Again, if a run created is worth the same as a run saved, these two should be roughly equal in terms of overall value.

Next I added Adrian’s defensive runs saved approximation (10 runs, I termed it "Appx D" for simplicity) to THT’s RC, as an estimate for the total value of runs Beltre has contributed altogether (Defense+Offense). I divided the new number by the old RC, since the old RC only accounts for offense. Again for the sake of simplicity, I termed this value Ddif.

Finally, I multiplied this value by all of the core stats (this is where regression analysis would likely come in handy, in case he had an uncharacteristic amount of home runs, etc., but that’s not something I plan on doing). PA would not change because the purpose of this is to show what Beltre would have had to bat in order to equal the runs he saves defensively over average in the same amount of plate appearances. AB does change to account for the walks, but it is not multiplied by Ddif either, because it is based on PA.

(note: I’m still not positive if I should be including walks, but they will remain included for now)

I then found what the new and updated BA/OBP/SLG would be for Beltre. Assuming he saves 10 runs above average with his glove, if he was an average defender, he would have to bat .312/.359/.546 to produce the same amount. Or, if you want to put it in more positive terms, Beltre essentially had a .905 OPS in 2007 if he were an average defender.

(For those that are curious, at 5 < x < 15, Beltre is .294/.339/.514 < x < .331/.378/.579)

I’m positive there is a better way to do it, and I’m positive someone has likely done this before. But at least these numbers give you a very easy to calculate talking point if you are trying to explain why Beltre is worth the money. If he saves 10 runs with his glove above average, he was essentially a .905 OPS, rather than a .802 OPS.

I termed the stat rLF to stand for two things: Replacement Level Fan (as in, a number that casual fans can understand) and "Raul in Left Field." So, for fun, I’ll also address the latter of the two.

For Raul in 2007, if we assume he ONLY caused 20 runs to score below average (and I think it is possible it is more like 30 or more), Raul – as an average defender – put up a .231/.284/.380, or a .665 OPS.

So that is my quick stat using what little I know about [baseball] statistics. At the very least, it will make it a little easier to talk about the value of Beltre and other players to casual fans, and although I’m sure there must have been someone that has done this before, hopefully this works as an easier way to calculate it.


Edit - Jeff sent me Tango's RC. I like using the idea of Tango's RC more, since they are not dependent on the situation the player actually encounters, but an approximation of what each one is worth with the situation removed (much like defense). I'm not going to retype this whole thing, but you can find Tango's numbers here. And here is the result:


I like this result much better. Beltre becomes a 300 hitter with above average power and good defense. Ibanez is not god awful but for a left fielder he comes basically useless.


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