How bad is an 'average' runner?

So I'm watching Friday's Pirates-Brewers game online on Fox Sports Wisconsin, and I come across this gem. Top of the second, no outs, Adam LaRoche on first, Xavier Nady strikes out on a hit-and-run attempt and Johnny Estrada easily throws out LaRoche on his way to second. The Brewers announcers take turns complimenting Estrada's defense, and the color commentator (Bill Schroeder, I believe) commentates:

As a catcher, what you really want to do is throw out the average baserunners. The Freddy Sanchezes and Jack Wilsons are gonna get their stolen bases, but you really need to get the average runners, and Estrada got LaRoche.

Here are some fun numbers I found on the internets:

Jack Wilson

2006: 142 G, 4 SB, 3 CS

Career: 889 G, 30 SB, 22 CS

Freddy Sanchez

2006: 157 G, 3 SB, 2 CS

Career: 350 G, 5 SB, 4 CS

Adam LaRoche

2006: 149 G, 0 SB, 2 CS

Career: 426 G, 0 SB, 4 CS (the play in question becomes career CS number 5!)

So, what you really aspire to do as a catcher defensively is to throw out guys who have attempted five stolen bases in their careers. The guys who steal one base successfully per thirty-five games, well, they're just gonna get their stolen bases.

If LaRoche is an 'average' baserunner, then who is a 'bad' baserunner? And if Jack Wilson and Freddy Sanchez are above-average baserunners, does there exist a word in the English language to convey how good of a baserunner Carl Crawford is? Maybe something Dr. Seussish? Fanshmablasticular?