Right, it's mostly just a matter of how much m...

2009-12-08T07:02:49.911-07:00

Right, it's mostly just a matter of how much math you're willing to do and how precise you want to be. (2*OBP+SLG)/3 is good because it is simple to calculate, whereas 1.75*OBP is a pain to try to estimate in your head, so it loses a little functionality. (1.75*OBP+SLG)/3 is better if you have a spreadsheet or calculator or something, and it's still simple to remember the formula and type it in, which is probably the biggest advantage over something more precise like the equation in the article. If you are doing a whole list of players and are running the calculations in Excel, the complex formula wouldn't be much more cumbersome than the simpler formula, except there's no way someone will have the more precise formula memorized for immediate use. Also, as long as you are using 1.75 instead of 2, you'd probably want to use a divisor closer to 3.05 to scale the mean a bit better, which goes back to how precise do you want to be compared to how much you want to have to remember or rely on computational aids.

Honestly, I don't think the formula in this article is of much practical use except in a few rare cases (though if you do want to be more precise and don't mind a little extra work, I guess it's up to someone to decide if it's worth using). If there is something of use to take from this exercise, it's probably that OPS (or other incarnations thereof) are a messy operation that doesn't really work off of a clean set of logic like something like wOBA. Combining unlike terms such as OBP and SLG distorts value to some extent even if you weight them properly, and they happen to work well enough at valuing most players mostly by accident.

Not that you should really care about that if you are just trying to get a quick and decent estimate of a hitter's value. The shortcut works well enough, so you might as well take advantage of that.

The biggest problem with (2*OBP+SLG)/3 is that the...

2009-12-06T23:45:44.723-07:00

The biggest problem with (2*OBP+SLG)/3 is that the "2" is an oversimplification. It's been known for awhile that the best fit is a multiplier around 1.75. Just use (1.75*OBP+SLG)/3 and you will find the league average is very close to .330.

Of course your fitted curve will give a better fit than a linear equation, but it's not always worth the extra math.

Comments on 3-D Baseball: Converting OBP/SLG to wOBA

Right, it's mostly just a matter of how much m...

The biggest problem with (2*OBP+SLG)/3 is that the...