When should I try to pick a guy off at First?

Sunday, one of my catching students asked me, "when is the best time to try and pick a guy off at first?" 

The answer is actually three-fold.

The very best time for a Catcher to pick a guy off at first is when your pitcher is in trouble, the bases are juiced (which would cause your first baseman to be behind the runner) and you need to do something to help him get out of the inning.  In college, my first baseman (Todd Wodraska, now Vice-Mayor of Jupiter, Florida...And one of the best first basemen I ever played with) and I could look at one another and "just know" when he would creep in behind the runner to set up the pick.  However, if you don't possess this higher level of communication, a simple "open glove" sign from the first baseman, followed by a rub of the cleat by the catcher should do the trick.

The second thing you should look for is you should identify the "slowest" guy on the team (meaning, more often than not, he is a poor baserunner) and the "fastest" guy on the team (meaning, he'll take chances trying to get a big jump) immediately.  Both of these types are excellent candidates for a pick, and should be noted by the catcher and first basemen as possible targets.  Normal, middle-of-the-road type runners are usually very conservative on the basepaths and as a result, very hard to pick.

And the third and perhaps most important thing you should look for (pay attention:  this is more advanced, professional type instruction) is a "Bunt and Miss", or a "Swing and Miss" with a Left Handed Hitter at the plate.  In these two situations, the baserunner will "lean" setting up the quick pick from behind the hitter due to the fact his sightline of the catcher will be blocked by the hitter at the plate.  This situation, (with respect to the score, the inning, the dominance (or lack thereof) of your pitcher) is the perfect situation for a pick.  And both Catcher and First Baseman should anticipate the moment, and once it happens, "carpe diem" or "Seize the day!" and pick that runner off!