THE THINGS YOU LEARN

Erik,

Remember during game 3 of the Cubs/Padres contest we were trying to figure out what a slugging average is? Well, I found a formal definition, which meant nothing to me until I pencilled it out. Here's how it works:

Slugging percentage is a statistical measure of a batter's effectiveness in making extra-base hits. A single is worth one base; a double, two; a triple, three; and a home run, four. Slugging percentage is total bases divided by at-bats.

That sounds all well and good, but for a math-addled loser like me, it's meaningless. But here's what it looks like when you compare two players with entirely different at-bat experiences in a single game.

Game 1
	Joe Batter	Bob Hitter
Singles	1(=1)	0
Doubles	1(=2)	0
Triples	1(=3)	0
Home Runs	1(=4)	1(=4)
At Bats	4	1
SLG	2.500	4.000

In the example above, Joe gets four hits, totalling 10 bases, divided by 4 at bats, for an improbably high SLG. Bob is at bat once, but hits a home run, giving him a significantly higher SLG. The SLG is relatively unforgiving and rewards only high extra bases: Bob performed fewer times and probably yielded fewer runs, but Joe had more chances at bat. How might the figures have changed if each had been at bat only once, or 4 times?

Game 2
	Joe Batter	Bob Hitter
Singles	3(=3)	0
Doubles	0	0
Triples	1(=3)	2(=6)
Home Runs	0	0
At Bats	8	2
SLG	0.750	3.000

In this example, Joe has 4 hits worth 6 bases, three of them "only" singles, but is at bat 8 times, lowering his overall SLG. Bob is at bat only twice, but gets two triples, which gives him 6 bases, proving he's a more effective batter than Joe. Interesting stuff, eh?