Looking at an alleged “efficiency” statistic and why the advice is useless.
Regular readers know that one of my pet peeves is when self-proclaimed experts give bad advice. To be clear, I do not consider myself or our other contributors to be “experts” as I defined them here. We all strive to become experts, but there are very few. Some attain expert status by acclaim, but other foist it upon themselves.

Of course, it is the self-proclaimed expert that you need to be wary of in your daily travels in cyberspace. Some of them routinely give bad advice, or at least worthless advice. Much of it is under the guise of “statistics” or “analysis.”

Here is another example from a site that I have referred to previously. The podcaster “invented” a new stat that he called an efficiency stat. Is it a complicated metric of the kind you might find on BaseballHQ or Baseball Prospectus?? Not quite. It was a simple ratio stat; for runs it was AB/runs, for RBI it was AB/RBI etc.

Two problems here. The first is that he called it a ratio of runs per AB and RBI per AB. But that is wrong. What he is measuring is the converse; it is the number of at bats per counting stat. This is the type of error that no serious analyst or expert could make; it is on the order of simple arithmetic.

With regard to the “stat” itself, as he defined it, the stat can have value in analytical terms, or in leagues with at-bat caps. But even there he is way off. But the basis for the stat was that it was supposed to target guys that are “efficient” at accumulating the stat.

For that purpose the stat is not really that helpful. Why?? Because of playing time. It does you no good to use an at-bat/counting stat ratio to measure accumulation. The way to accumulate runs or RBIs is to get players that will have at bats AND will get those stats. This should be self-evident, and probably is to most of us.

What is worse is that this stat is used to give us sage advice like “try to acquire A-Rod or Gary Sheffield.” Thanks for the tip. To be fair though; he did point out that Carlos Pena was having a surprisingly good year and should be targeted over some other big name players. That advice is helpful. But you don’t need a contrived, incorrectly defined stat to figure it out.

The second problem is that ABs is not the most useful measurement here. The reason should be clear: it ignores walks. When I am trying to accumulate runs or stolen bases I don’t ignore walks. A SB or run scored on a walk is just as good as one scored on a hit. Since he was allegedly tailoring this advice to Yahoo leagues that had at-bat maximums, ignoring walks is even worse!! If you are trying to accumulate a stat while minimizing at-bats, walks are the perfect vehicle. A guy with a lot of walks will accumulate the stat on his walks without using up at-bats.

The use of At-Bats also changes the result. Lets take a quick example. Nick Swisher has 314 AB, 42 runs and 70 walks. By the “efficiency” stat Swisher has a ratio of 314/42, or 7.47. Including walks, his runs stay the same, but his numerator changes to AB+BB, this gives a ratio of 9.14. A lower number is better, according to the metric. So including walks apparently makes him LESS efficient(!)

In the case of a player with very few walks, the ratio will not change nearly as much, for obvious reasons. Taking Kenji Johjima for example: he has 291 AB, 32 runs and 11 BB. So his ratio using AB only is 291/32 or 9.09. Using BB in the numerator, we get 291+11/32 or 9.43.

Simply put, the definition used by the podcaster radically alters the results in the instance where a guy has a lot of walks. Yet if you want to measure someone’s efficiency at accumulating a counting stat why ignore, in the case of Swisher, those extra 70 plate appearances??

Nothing here is earth shattering, but on the other hand, it shows that even simple analysis is needed since self-proclaimed experts can get it wrong. Don’t take any analysis at face value. Try to become an expert yourself; then you can avoid being misled by non-expert advice.

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