Wednesday, June 27, 2007

Five Baseball Stats You Should Know

I'm not sure if anyone else will give a crap about these but I just finished reading Moneyball and they seemed pretty interesting to me. These are not the five most important stats, in fact some may be completely worthless.


This one most people have heard of already but I thought I would try to explain exactly what it’s quantifying and why it’s so much better than Batting Average. OPS actually stands for “On-base plus slugging” and it is essential measuring the same thing as runs created, just in a much simpler way. The on-base percentage represents the “on-base factor”, while the slugging percentage represents the “advancement factor”. OPS just adds them together instead of multiplying them. OPS is a far better indicator of a players offensive contribution than BA because it takes into consideration most of the statistics that lead to runs, not just hits.

Range Factor

= (Putouts + Assists) / Innings Played

It’s a much better measure of defensive ability than errors, because if you think about it, errors are completely subjective. An error is one person’s opinion of a play made (or not made) on a ball the fielder was able to reach. Range factor takes into account how many balls the fielder was able to reach, thus giving a better indication of their actual contribution to the team.

Runs Created

Created by Bill James, it takes a hitter offensive statistics and uses them to assess how many runs he essentially “created”. It can be summed up by saying it is equal to the product of the on-base factor and the advancement factor divided by the opportunity factor. The actual equation is a little more complicated:

(H+BB–CS+HBPGIDP)*(TB + (.26*(BB-IBB+HBP)) + (.52*(SH + SF + SB)))
= -------------------------------------------------------------------------------
(AB + BB + HBP + SH + SF)

Yikes. How it works I’m not exactly sure, but I trust Bill James because he’s much smarter than me. I did try it out that and it’s pretty accurate. So let's take the hottest hitter in baseball right now, Magglio Ordonez. He created 81 runs for the Tigers as of yesterday. Just how important is that to his team? Let's see what would happen if we switched him with one of the worst right fielders in baseball, the Cubs' Jaque Jones, who has contributed only 19 runs to his team. That's right, 19! In order to find out the effect of the hypothetical switch we need to look at....

Pythagorean Win Expectancy

This much simpler formula attempts to predict how many should have won based on the number of runs they scored and the number of runs they allowed. The theory is that:

Win % = R2 / (R2 + RA2)

Using this we can find out how many wins the Cubs and Tigers would be expected to have if they had the other team's right fielder. I took the difference in run contribution between the two players (62) and added it to the Cubs total and subtracted it from the Tigers total. The result? The Cubs would have won 7 more games because of Magglio and the Tigers would have lost 5 more. Kind of interesting. And now for our last stat...


League Leaders
(748 Tied)...........2
Mike Lowell........1 (don't laugh he had testicular cancer)
Alex Rodriguez...0

.....just in case anyone was still reading.


Guy said...

You should check in with A-Rod's Playmate-on-the-side (or Jeter, either or) to confirm your hypothesis.

Either way, nice burn.

Daris said...

good stuff log. you should attach a spreadsheeet with your calculations, i want to see proof.

Daris said...

just to let everyone know, log did send me his spreadsheet comparing jones and faglio so that I could audit it.

It is my opinion that his numbers accurately reflect the effects the player switch would have on each team. (FASB No.234)

Dr. Health said...

Range factor takes into account how many balls the fielder was able to reach, thus giving a better indication of their actual contribution to the team.