Catching depth is hard to come by. That needs to be said from the outset for anyone scratching their heads wondering why the Kansas City Royals would give up anything for a back-up catcher from the Houston Astros of all teams, especially one with back problems. After all, the numbers for Humberto Quintero are not inspiring.

A closer look reveals that Quintero is among the worst hitters in baseball. Last year, he hit .240 with 2 home runs and 25 RBI. That was his best batting average since 2006. Enough said there. However, the Royals gave up Kevin Chapman for Quintero's defense. How much that's worth is, well, very difficult to figure out, to be honest.

Baseball Nation's Jeff Sullivan takes a closer look and writes, "Obviously, it's defense. Last summer, Mike Fast studied the effect of pitch-framing, and Quintero scored well. His receiving was found to save about five runs per full season over the average backstop. Beyond that, last fall, Bojan Koprivica studied the effect of pitch-blocking. Quintero scored very well. In fact, he finished first, as the best pitch-blocker in baseball. That's another five or six runs per full season over the average backstop."

For more on the Royals trade, check out Royals Review.