Left-handed specialists are the field-goal kickers of Major League Baseball, and the St. Louis Cardinals just signed theirs, 37-year-old sidearmer Randy Choate, to a three-year deal. It's not worth very much money—$7.5 million, apparently—and Choate is very good at his job; since reaching the majors with the New York Yankees in 2000, he's held left-handers to a career line of .201/.278/.284. He'll give the Cardinals a lockdown option against top left-handed hitters, and he's proven himself able to go 80 times in a season.

But: He also barely pitches. Like a placekicker, he's on the field all the time, but he's rarely there for very long. In leading baseball with 80 appearances last year, Randy Choate completed a grand total of 38.2 innings. Jaime Garcia, the Cardinals' injury-plagued walking World Baseball Classic controversy, threw 36 innings in September, while his shoulder was falling off. To steal another football term, bringing him in is like calling a trick play—you have to make sure the situation is right, and you have to be certain the other team won't react quickly enough (in this case, with a pinch hitter.)

In his last three years, Randy Choate threw about 108 innings. He was better than the kind of starter you'd get for $7.5 million these days, but only against certain players—and only for a little more than half as many innings as you'd expect from a guy making 30 starts. The Cardinals got what they wanted, but what they wanted is a very specialized tool for one of their 25 active roster spots.