Friday, December 19, 2008

Huh? Part 1: VORP

I've got some time off, thanks to the holidays, so expect the postings to ramp up. Remember when you could look on the back of a baseball card and see a player's batting average and RBI and doubles, and ridiculously false notes about a different player completely? (Not kidding: I saw a baseball card for a not-very-well-known player that said Mark Koenig threw a baseball 130 mph in the 1930s. Just...false.)

Today it feels like you need a slide rule to follow which players are actually good. Damn that Rob Neyer with his....math and his...statistics! Well, today we begin to explain some of the less obvious (though helpful) statistics.

VORP: Value Over a Replacement Player.

Baseball Prospectus defines it as "The number of runs contributed beyond what a replacement-level player at the same position would contribute if given the same percentage of team plate appearances. VORP scores do not consider the quality of a player's defense."

The Replacement Player "performs at 'replacement level,' which is the level of performance an average team can expect when trying to replace a player at minimal cost, also known as "freely available talent." So maybe "Value Over the Astros" is more accurate.

How do you find it?

1. Find the league's average runs per out.

2. Multiply this by the player's total outs. The resulting number is the number of runs an average player would have produced with that number of outs.

3. Muliply the number of runs by .8 (the number depends on the position),

4. The resulting number of runs is what you would expect a Scrub to put up.

Now you need to know how many runs your Starter created. Runs Created was "invented" by Bill James (now a special advisor to Theo Epstein), where the goal is to determine how many runs a player creates (this isn't hard. Well, the definition isn't, anyway).

To determine Runs Created:

1. Add the number of hits to the number of walks.

2. Multiply by the number of total bases.

3. Divide by the number of at-bats plus walks.

4. This is the Runs Created (generally divided by some number of outs).

Simply subtract the replacement's runs created from the player's actual runs created, and the result is VORP.

It's not easy. It basically is a more accurate way of measuring a player's value over a scrub. But listen, no one's going to go figuring this out on their own, so let somebody else do it. Like Baseball Prospectus. According to Baseball Prospectus, who are the three Astros with the largest VORP?

Lance Berkman: 72.5
Carlos Lee: 44.1
Ty Wigginton: 26.2

Michael Bourn actually has a VORP of -11.8, meaning a replacement player would be an upgrade over 2008 Michael Bourn. But that's not nice.

If you didn't know, now you know.