Buster is an interesting study. We picked him, mostly as a shortstop, for the Aflac All American game after his jr year in high school. He was a shortstop/RHP.
Here is one report from 2004.
Buster Posey is a strong lean athletic 6'1/180 RHP/SS from Leesburg, GA. Posey is already a polished four pitch pitcher with excellent athletic ability. He threw an effortless 90-92 mph with a sharp, deep slider, a power curveball and an effective fading change up. He’s one of the very top pitchers in the 2005 class. We've seen him up as high as 94 mph with very good command. He's also a highest level SS with his great arm, good hands and nice actions. He shows big time hitting ability also with surprising power. At the top college in the country he is a top player immediately. It will be interesting to see if MLB clubs will draft him early as a pitcher. He's got one of the very best arms in the country, but he's not the big RHP they normally draft early. Buster is an excellent student. He was selected to the AFLAC All American Team. PG Grade: 10
Perfect Game USA's Player Rating System
10 - Potential very high draft pick, Top DI in the nation prospect
I thought he was a top 3-4 round type coming out of high school as either a shortstop or a pitcher. He was a Freshman all american as a shortstop his first year in college. Thanks to the coaching staff at Florida State he became a catcher the following year. At that position he became a cinch first rounder.
I'm sure, looking back at it, that the scouting community did NOT see Buster as a first round type out of high school. 50th round was because Buster really wanted to go to college and didn't beat around the bush about that. If signable at that round, he would have went top 5 rounds IMO. However, then would he be the catcher we now know? College (Florida State) was great for him!