bird dog
n.— «I think that I cannot provide you with any type of definite answer. I don’t think that there is any type of machine. We have what is called the bird dogs, and we try to identify the players quite early for the pitchers.» —“2006 World Baseball Classic: Round 2 Interviews: Workout Day In San Juan: Manny Acta” in San Juan, Puerto Rico Noticias.info Mar. 11, 2006. (source: Double-Tongued Dictionary)